HK1162625A - Monitoring system for concrete pilings and method of installation - Google Patents

Description

Concrete piling monitoring system and installation method

Technical Field

The present invention relates to a monitoring system for long term tracking of concrete pile foundations and structures, and to a method of installing and connecting such a system to pile foundations and structures having measuring instruments and sensors pre-cast therein.

Background

Currently, there is no effective method for communicating information from concrete structures such as pile foundations or pier pitches to determine the structure or the conditions generated by installing the structure, and since the manual addition of strain measuring instruments/accelerometers and other monitoring devices to monitor the force and speed in the pile foundations during installation requires a large amount of work, only about one tenth of the concrete structures such as the pile foundations to be monitored are actually monitored for pressure load and stress/strain related information. When a pile foundation is typically placed with the neckline cable around the structure, and then the structure is lifted with a crane, it is not possible to place anything on the outside of the pile foundation, as it may have a high risk of damage or cutting out by the neckline cable during placement. Currently, after placing a pile foundation for driving, manual attachment work is performed on the required measuring instruments and sensors in such a manner as to climb to a desired position and attach the measuring instruments and sensors to the fixed pile foundation. This is not only labor intensive, but also time and cost intensive, and may pose a safety risk to the personnel. Therefore, limited monitoring is typically performed, and therefore a high design safety factor is required for the structure. A method of enabling wireless monitoring during driving would be of significant value, reducing the cost and time associated with the testing process, thereby enabling more tests to be performed. However, there are a number of technical obstacles to doing so, including the wireless transmission of sensor data from the pile foundation.

The fundamental problem with placing a radio frequency antenna against or embedding a radio frequency antenna in concrete is that the performance of the radio frequency is greatly reduced due to the large dielectric composition of concrete over time. This represents a very difficult and challenging application environment. For air with a dielectric constant of 1.0 and water with a dielectric constant of 80, the concrete varies between 20 (new) and 6 (after two or three months of complete curing, depending on the water content).

The concrete structure in this application will be used 28 days after casting, or at a faster time, and then has a dielectric constant of about 9.0.

Placing relatively high dielectric value concrete close to the radio frequency antenna causes most of the energy radiated by the (currently detuned) antenna to radiate from the antenna and into the concrete. A typical antenna is designed to operate in a free-air environment regardless of whether the remaining radio frequency energy associated with the free-air is severely attenuated by a distorted and/or unstable pattern (pattern).

Furthermore, after the structural element, such as a pile foundation, has set, no more data are collected for analysis, which can be used, in view of cyclic loading, for long-term stability and structural integrity of the structural element and for monitoring that the structural element, when exposed to a harsh environment, may degrade over time and cause structural damage.

It would be desirable to provide a more efficient and cost effective method and system for monitoring such concrete structures during the entire useful life of the structure. It would be further desirable to provide a system that can be easily deployed during the casting and manufacturing process, which can be monitored in a cost effective manner, and thus can monitor all concrete structures in a particular application, and particularly pile foundations for buildings, bridges and roadbeds, to allow for a more efficient use design without compromising the safety and reliability of the complete structure. Furthermore, it would be desirable to provide a system for life cycle monitoring of a concrete structure containing all concrete structure elements, regardless of whether the pilings are cut off at the top after setting. It is also desirable to provide a method of monitoring buried metrology instruments regardless of the final state of the structure.

Disclosure of Invention

The present invention provides a system for tracking and monitoring manufacturing, installation and/or life cycle related data for concrete structures such as foundation piles, and related system components and methods for tracking, storing and accessing such data.

The invention provides a method for monitoring a pile foundation, which comprises the following steps: inserting a sensor sleeve between the strands or reinforcements in a pile form to place the sensor in a core region of a pile; connecting a radio module to the pile foundation, the radio module in communication with the sensor suite; casting the pile foundation; driving into the pile foundation and obtaining data from the sensor package during driving; monitoring data from the sensor package during driving and at least one of monitoring and using the data during driving to adjust driving parameters for the pile foundation; and using absolute internal strain information from the data obtained from the sensor package within the pile core to maximise driving efficiency in real time during driving of the pile.

According to a preferred embodiment of the above method, further comprising: the absolute internal strain information is monitored to ensure that the driving force does not exceed a level that creates an damaging tensile stress condition in the pile foundation.

According to a preferred embodiment of the above method, further comprising: monitoring the absolute internal strain information to change preload during the driving; and using this information to predict pile foundation failure.

According to a preferred embodiment of the above method, further comprising: the sensor package is inserted into a top end of the pile foundation and a second sensor package is inserted into a top portion of the pile foundation.

According to a preferred embodiment of the above method, further comprising: detecting irregular wave velocities using the data and a known distance between the sensors in the pile foundation; and comparing the irregular wave velocity with a predefined condition for a failed detection.

According to a preferred embodiment of the above method, further comprising: data from the sensor package is stored in a memory.

According to a preferred embodiment of the above method, further comprising: the data obtained is transmitted to a pile history database for further life cycle and long-term monitoring.

According to a preferred embodiment of the above method, further comprising: retrofitting the pile foundation by providing a network monitoring node connected to the sensor suite; the specific address information of a known pile foundation is reserved by logically linking a sensor suite address identification; and connecting the node to an external gateway for long-term monitored data transmission.

According to a preferred embodiment of the above method, further comprising: cutting off a top of the pile foundation; and pulling excess wire or cable located within a hollow tube from a wire reservoir adjacent a top end of a pile to connect the sensor suite located at a top end of the pile to the network monitoring node.

According to a preferred embodiment of the above method, further comprising: the position of the sensor assembly is fixed using a spring loaded support member having a U-shaped frame that is inserted generally vertically into the pile form and resiliently engages at least two opposing strands via an outward spring force.

According to a preferred embodiment of the above method, the method comprises: forming a cast concrete pile foundation having a sensor package located in a core region of the pile foundation; driving into the pile foundation and obtaining data from the sensor package during driving; retrofitting the pile foundation by providing a network monitoring node connected to the sensor suite; the specific address information of a known pile foundation is reserved by logically linking a sensor suite address identification; and connecting the node to an external gateway for long-term monitored data transmission.

According to a preferred embodiment of the above method, further comprising: pile foundation data is stored in a memory located in the pile foundation.

According to a preferred embodiment of the above method, further comprising: for a pile foundation which is cut off at its top after driving, excess wire or cable located within a hollow tube is pulled from a wire reservoir adjacent to a top end wire or cable reservoir to connect a top end sensor package to the network monitoring node.

According to a preferred embodiment of the above method, further comprising: providing a global position determination system at the pile foundation; obtaining a position of the pile foundation; and obtaining soil properties of the location.

According to a preferred embodiment of the above method, further comprising: providing a rewritable memory in the pile foundation; and storing and updating the data in the rewritable memory.

According to a preferred embodiment of the above method, the suspension assembly comprises: a first U-shaped frame and a second U-shaped frame connected to each other; at least one strand engaging member located on each of the U-shaped frames offset facing each other and adapted to engage opposing reinforcing strands or rails of a concrete structure; and a slidable shelf attached to the frame for supporting at least one measuring instrument.

According to a preferred embodiment of the above method, at least one of the strand engaging members is formed from a spring material.

According to a preferred embodiment of the above method, the first and second U-shaped frames are resiliently biased away from each other; and a center spring extending between the slidable shelf and the frame to center the slidable shelf in the U-shaped frame, the slidable shelf including the provision of an additional sensor.

According to a preferred embodiment of the above method, further comprising: a first opening having at least two opposing V-shaped sidewalls for registering a first induction housing located in the slidable shelf or a mosaic plate connected thereto; and a second opening defined in the slidable shelf or the mosaic plate connected thereto for a second sensor.

According to a preferred embodiment of the above method, further comprising: a strand measuring instrument connected to the sliding shelf.

According to a preferred embodiment of the above method, further comprising: an accelerometer connected to the sliding shelf.

In one aspect of the invention, a permanently embedded antenna with a reflector is provided that does not protrude from the surface of the structure during manufacturing and transport. The antenna is inserted flush into a side wall of the concrete structure and extends only from the exterior surface to a limited extent into the structure, thus not compromising the structural integrity. In addition, the antenna is far away from the steel rib inside the structure, so that the loss of the integrity of the related structure caused by the entry of moisture is avoided.

The antenna inlay/design must be able to withstand repetitive shock application environments with high amounts of hammering up to about plus/minus 1000 times the gravitational acceleration force. This may occur, for example, during the driving of reinforced concrete piles.

In addition, the antenna is in an external operating environment that contains moisture exposure, but does not retain or retain moisture to avoid damage or failure of the antenna's performance.

The antenna of the present invention is permanently embedded in the structure and it is disposable and has low cost characteristics.

According to another aspect of the present invention, an antenna device is provided that is buried below the surface of the concrete structure during manufacture. The antenna assembly includes an actuator that moves the antenna from a first stowed position to a second deployed position in which the antenna projects from the concrete surface. The actuator may be triggered manually or by a specific load or directional shock wave transmitted through the concrete structure, such as a first blow by a pile driving hammer, or by a control command or other electronic signal.

The present invention also provides an economical and fast method of installing sensors and instrumentation into a pile form using a U-beam suspension assembly in a simple and repeatable manner prior to casting. The U-beam suspension assembly provides vertical positioning of the sensor/gauge, reducing possible damage to the sensor/gauge during casting, and preferably automatically centers the sensor/gauge in the pile form prior to casting to ensure correct reading of the sensor.

The invention also provides history tracking and log memory to allow for tracking of pile information during complete setting of the pile, which information may also be used to provide active feedback to the worker during setting.

The invention also provides a method for monitoring the life cycle of pile foundations and other concrete structural elements. The method comprises the following steps: one or more sensors/gauges are inserted between the strands in a pile form to position the sensors in a pile core area. This may be, for example, strain gauge instruments, accelerometers, pore pressure, temperature and/or humidity sensors, and the like. Pile casting is then performed and the sensors are enclosed together. Preferably, a radio/antenna assembly is placed in the form and is also pre-cast into the pile by exposing at least the antenna on the side adjacent the top pile. The pile is driven into the pile at the construction site and data is obtained in real time from the sensor/gauge suite during the driving. The data is transmitted to a control/monitoring system for real-time inspection and analysis of the incoming data. After driving into the pile foundation, the pile foundation is refurbished with a network monitoring node that is connected/bonded to the existing sensor/instrumentation package. Unique address information for a known pile foundation is maintained, preferably by logical link sensor package address Identification (ID). These nodes (and potentially nodes from other sensors in the complete structure) are then connected/simulcast to an external gateway to allow for lifecycle monitoring of some or all of the complete structure.

Drawings

The foregoing summary, as well as the following detailed description of preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustration, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements shown.

Fig. 1 is a perspective view showing a strand in a pile form prior to casting concrete in the form to form the pile.

Fig. 2 is an enlarged perspective view similar to fig. 1.

Fig. 3 is a perspective view showing the pile form exterior after concrete has been cast in the form.

Fig. 4 is an exploded view of a first embodiment of an antenna assembly according to a first embodiment of the present invention.

Fig. 5 is a cross-sectional view of the antenna shown in fig. 4 embedded in one side of a concrete structure such as a pile foundation.

Fig. 6 is a perspective view showing the position of the relative antenna on top of a pile foundation.

Fig. 7 is a side view of a deployable antenna assembly flush mounted to a surface of a concrete structure.

Fig. 8 is a perspective view of the antenna of fig. 7.

Fig. 9 is a perspective view of an alternative embodiment of a deployable antenna according to the present invention.

Fig. 10 is a perspective view of a partially detachable reflector used to form another antenna assembly according to the present invention.

FIG. 11 is a perspective view showing a portion of a removable second reflector assembly in accordance with the present invention.

Fig. 12 is an exploded view of an antenna housing and reflector assembly with an additional and externally exposed electronics module housing.

Fig. 13 is an enlarged cross-sectional view of the polymer plug used in sealing the antenna tube and housing shown in fig. 12.

Fig. 14 is a front elevational view, in the form of a first aft cover, of the antenna reflector assembly shown in fig. 12.

Fig. 15 is a front elevational view of a second aft cover of the antenna reflector assembly shown in fig. 12.

FIG. 16 is a perspective view of another antenna assembly according to the present invention, similar to that shown in FIG. 12, but without the electronics module housing.

FIG. 17 is a perspective view of an antenna assembly similar to that shown in FIG. 12 with a release liner surrounding the electronic module housing cover.

Fig. 18 is a rear perspective view of the antenna assembly shown in fig. 17.

Fig. 19 is a cross-sectional illustration through a pile form profile showing the relative positions of antenna assemblies according to the present invention in the pile form profile.

Fig. 20 is a cross-sectional view through the exterior of a pile foundation showing a strand and U-bar suspension assembly according to the present invention for vertical embedment of measurement instrumentation in the pile foundation.

Fig. 21 is an exploded perspective view of the U-shaped bar suspension assembly.

FIG. 22 is a side elevational view of a portion of the structure of the assembled U-bar suspension assembly with a strain gauge, an accelerometer, and an electronic module mounted thereon.

FIG. 23 is a side elevational view, similar to FIG. 22, of another embodiment of a U-shaped bar suspension assembly having the strain gauge, accelerometer, and electronics module.

FIG. 24 is a perspective view of the electronics and sensor mounted to the central portion of the U-shaped bar suspension assembly of FIG. 23.

FIG. 25 is a rear perspective view of a sensor shown in relative nesting relation to the U-shaped bar suspension assembly of FIG. 24.

Fig. 26 is a cross-sectional view of a water seal housing for the accelerometer.

Figure 27 is a structural illustration of a pile foundation showing the connection between the roof and top sensor/measurement instrument package and the radio/electronics compartment.

Fig. 28 is a diagram of a pile structure similar to that of fig. 27 in which the pile includes a wire reservoir and guide tube to allow a buried tip gauge to be connected to the pile, and after driving, the pile has a cut-away top.

Fig. 29 is a cross-sectional view through the pile foundation, taken along line 29-29 of fig. 28.

Fig. 30 is a structural view of the pile sensor and antenna device of fig. 28, which does not show the pile.

FIG. 31 is a block diagram of a pile foundation showing the common data backbone and an in-pile transmission system.

Fig. 32 is a perspective view of a top of a drive-in pile with radio electronics replaced by network node modules.

FIG. 33 is a perspective view of a pile foundation with cut-away top portions showing connection to a network node module.

FIG. 34A, B, C is a flowchart illustrating a life cycle monitoring system according to the present invention.

Figure 35 is a perspective view of a concrete cap cast over the top of a plurality of pilings having monitoring sensors connected together at a node for connection to other elements of the structure and/or telemetry chaining for data acquisition and monitoring.

Fig. 36 is a perspective view of a system for tracking the depth of penetration of a pile foundation according to the present invention.

Fig. 37 is a perspective view of an alternative system for tracking the depth of penetration of a pile foundation.

Detailed Description

Certain terminology is used in the following description for convenience only and is not limiting. The words "below," "above," "left," and "right" refer to directions as indicated in the drawings. As used herein, the recited use of "at least one of A, B and C" means either A, B or C, or any combination thereof, wherein A, B and C represent the noted features of the invention. Accordingly, the terms "a" or "an" are defined as including one or more of the referenced item, unless specifically indicated otherwise.

Referring to fig. 1, there is shown the placement of the strands 12 of a pile foundation 10 within a pile foundation form 14 prior to the casting of concrete on the pile foundation form 14 to form a pile foundation 10. Sensors 16 and antenna elements 18 for transmitting data from the pile during or after set-up are shown connected to the strand 12, or suspended from the strand 12 or above the strand 12, preferably by cable lashing or similar retaining means. Sensors and antennas for monitoring the pile foundation, preferably by direct wireless data transmission, transmit data collected by sensors embedded in the pile foundation for setup and/or life time monitoring of the pile foundation, and possibly also for storing pile foundation data, as described in more detail below.

Fig. 2 shows an enlarged view of a preferred antenna/radio assembly 60, the antenna/radio assembly 60 being temporarily positioned on top of the pile strand 12, the strand 12 then floating in the concrete cast in the form, so that the top surface of the antenna/radio assembly 60 will be positioned on the surface of the pile. In addition, the sensor 16 is attached to a preferred suspension assembly for positioning the sensor between the strands 12, which will be described in further detail below.

Figure 3 shows the piling 10 being cast on the outer form 14 after the concrete has been poured. The surface of the antenna 18 is left exposed for signal transmission before, during and/or after driving of the pile. Likewise, the cover 64 of the antenna/radio assembly 60 maintains an exposed cover. As described in detail below, the antenna 18 may also be removed and associated with the cover 64 of the electronics module housing.

Fig. 4 and 5 show a first embodiment of an antenna assembly 18 according to the present invention. The antenna assembly 18 is then flush mounted on the concrete structure side of the pile foundation 10 or the like as shown in figure 3 during manufacture. It must be ensured that the antenna can be decoupled from the surrounding concrete of the pile foundation 10. This can be achieved by providing a corner reflector 24, preferably made of metal, such as steel or aluminum, or plastic with an electrically conductive coating. Although gain has been achieved in other ways by previous corner antennas, in this case insulation is provided in an unconventional manner between the antenna and the surrounding concrete structure 12 in which it is embedded. In a typical corner reflector application, the reflector is placed at a wavelength away from the antenna 1/2 so that the reflected waves will sum up and gain in phase. Due to the depth limitation in the application of the present invention caused by the reinforcement in the concrete, the metal surface of the corner reflector 24 can be placed only far enough away from the antenna to minimize detuning effects on the antenna (causing loss of impedance errors), nor can the metal surface of the corner reflector 24 be too far away from the antenna to minimize destructive interference caused by the reflected wave. In one application, a preferred distance is 2.1 for a reference wavelength of 916 megahertz (MHz), which provides a space of approximately 1/6 wavelengths.

In another embodiment of the present invention having shorter wavelengths/higher frequencies (e.g., 2.4 megahertz (GHz)), a smaller overall geometry of the embedded antenna element is provided, requiring only approximately 1 inch of space.

Still referring to fig. 4 and 5, an antenna 26 is maintained in position relative to the back metallized reflector having an open cell foam block 28, or other similar moisture-impervious absorbing or supporting spacer. Preferably, a cover plate 30 made of a radio frequency transparent material for the frequency of interest is disposed over the antenna 26. Preferably, the cover is flush with the surface of the concrete structure 12, as shown in figure 3. Preferably, a clasp 31 is placed around the wire or coaxial cable extending from the antenna 26. The complete assembly 18 is preferably assembled using a water seal.

Referring to fig. 6, a preferred arrangement of antennas 18 at opposite faces at the top of the piling 10 is shown. Preferably, the antenna element 18 is located 2d below the top, where d is the width of the pile 10. The sensors 16 are preferably also located 2d from the top underside, while additional top sensors are located 2d from the pile top, as will be described in more detail below. However, the sensor is located at the center/core of the pile cross-section.

Referring to fig. 7 and 8, in another embodiment of the invention, a single (or multiple) retractable spring antenna element 50 is provided. The antenna 52 is maintained flush with the pile surface during manufacture and shipping of the pile. The antenna assembly 50 has an antenna 52 that extends to an extended position and activates solenoid-actuated release only after significant vertical blows such as a physical pile hammer or a control command. An electrically conductive ground 54, preferably made of metal or of an electrically conductive material coated on an insulating substrate, is embedded flush with the surface of the concrete structure, substantially until the antenna is deployed, on the surface as is the cover 30, and then serves as part of the antenna structure when deployed. The length of the antenna is preferably 1/4 lambda, and the ground 54 has a dimension of about lambda/2, which may be a circle or square having a diameter or side length of about lambda/2. While this configuration is preferred, other configurations may be used.

Alternatively, or in addition to distal release, a manual push button manual control 55 may be provided in the event that the automatic extending action of the antenna assembly 50 fails. This may be in the form of a small opening in the floor 54 that allows a user to insert a wand or pin to release the fastener that holds the antenna 52 in the stowed position.

Upon receiving a strike or control command of appropriate strength, the antenna 52 extends vertically from the concrete surface. As shown in fig. 8, this can be achieved simply through a hinge inlay antenna 52. The blow or control activates the solenoid or plunger which then releases the fastener and the antenna is driven and rotated outwardly by the force of a surrounding coil spring or compression spring (not shown). Alternatively, as shown in fig. 9, the assembly 56 may include an antenna 57 in a non-electrically conductive sleeve 58, the non-electrically conductive sleeve 58 generally extending perpendicularly from the surface of an electrically conductive ground 54a on the surface of the concrete structure, and then through a detectable blow as described above or through a control signal, a release catch is activated which releases the antenna 57 to twist outwardly from the sleeve 58 to an extended position above the ground 54 a.

If during set-up an antenna hits a plane (horizontal or ground plane), the internal sensing circuitry switches data transmission to an on-plane antenna, or to an internal radio transceiver in the case of a bonded pile, or allows a direct connection through the socket to output data, as will be discussed in more detail later.

Referring to fig. 10 and 11, two alternative embodiments of the antenna elements 80, 90 are shown. The antenna elements are constructed in a very cost effective manner and use a low loss and low dielectric value material plugs 82, 92 having a thickness of lambda/4, and preferably having a diameter greater than or equal to lambda/2. The plug may be made of plastic or any suitable material that meets the above requirements, preferably having a cylindrical (fig. 10), hemispherical or parabolic (fig. 11) shape. The sides and bottom are covered with an electrically conductive coating 84, 94, such as a metalized foil or any other suitable material. An externally sealed central opening 85, 95 is provided through which the central wires 86, 96 of a coaxial cable 88, 98 extend to a length of lambda/l. The ground braid cables of the cables 88, 98 are soldered together or otherwise connected to the electrically conductive coatings 84, 94 in the region of the central openings 86, 96 and extend through the tops of the plugs 82, 92. The top surface of the plugs 82, 92 act as a cover and are positioned flush with the concrete structure surface during manufacture to provide a low cost antenna.

Referring to fig. 12-15, a preferred embodiment of the upper antenna/radio assembly 60 is shown in detail. The antenna assembly 60 preferably includes a reflector assembly 65 having a reflector body 66 formed from a bent sheet of metal, preferably formed in a V-shape, and having a tail cover 68 and 70 attached to its tail as shown in fig. 14 and 15. Preferably, the reflector assembly 65 is formed from a metallic material, such as aluminum or stainless steel. However, other suitable metallic materials, or polymeric materials having a metallic coating, may be used. A protective cover 72 is provided that is formed using a radio frequency transparent material for the desired frequency. The protective cover 72 is required during pile foundation manufacture to prevent concrete from escaping the antenna assembly 60 during casting, and after the concrete sets, the protective cover 72 can be removed if desired. In a preferred embodiment, this is formed from a heavy card/card or polymeric material having a thickness greater than 0.02 inches and can be adhered, affixed or sealed to the reflector assembly 65.

The antenna assembly 60 additionally includes a housing 61 for wiring, and electronic components associated with the antenna 76, as well as a radio module for transmitting data signals. The antenna 76 is preferably located within an antenna tube 78 formed from a polymeric material such as polyvinyl chloride (PVC) and is preferably connected to the housing 61 in a water-tight manner using a coupler 69 extending from the housing 61, and a plug 79 is inserted from the housing 61 into the coupler 69 and around the antenna base, as shown in detail in fig. 13. The plug 79 is preferably sealed or glued within the housing 61, as at 81 registered. The reflector assembly 65 is disposed over the antenna tube 78 such that the first end cap 68 abuts the housing 61. After the antenna 76 is placed, the rear of the antenna tube 78 is sealed using a tube tail cap 83. A water seal connector 91 can be inserted into the opening on the side of the housing 61 to provide access for wires, cables, etc. with water sealing properties, further performing data signal transmission and transmitting power to various components in the induction system of the pile foundation 10. In addition, a buoyancy compensating plate 87 is preferably attached, such as by rivets, to a flange provided at the bottom of the housing 61, or by any other suitable attachment means, such as clamps, adhesives, cable ties, and the like. The buoyancy compensating plate 87 may be sized to bear a sufficient amount of concrete above it to resist the buoyancy of the antenna assembly 60, thereby maintaining a floating position above the pile strands so that the protective cover 72 is substantially flush with the pile surface.

Preferably, the housing 61, the coupler 69, the plug 79, the antenna tube 78, the anti-float plate 87 and the tube tail cap 83 are all made of polyvinyl chloride (PVC) or similar polymer material and can be combined or bonded together in a simple and efficient manner. The protective cover 72 for the reflector assembly 65 is preferably located within the pile form 14, thus forming part of the outer surface of the pile. In addition, an access cover 64 for the housing is preferably provided and also located on the face of the piling to allow access to the wires, cables, batteries, survey supports and/or electronic components located therein after the piling is formed.

Referring to fig. 16, a reflector element 89 for the second antenna element 62 is shown, including the protective cover 72 and the reflector body 66, which is preferably V-shaped. Two reflector tail caps 70 are used to close the rear ends of the reflector assembly 89 and position the antenna 76 therein in the antenna tube 78. Once the antenna is disposed within the tube 78, the rear end is sealed in a water-tight manner by a tube tail cap 83 or similar type of tail cap so that only the antenna cable extends outwardly from one end of the reflector element 89 to form the second antenna element 62.

Referring to fig. 17 and 18, a preferred antenna/radio assembly 60 with improved arrangement is shown. To allow removal of the access cover 64, a foam or rubber sleeve 63 is provided around the top of the housing 61 and extends up through the mouth of the access cover 64, as shown in fig. 17. This prevents the concrete used to form the pilings 10 from locking the position of the access cover 64 and after the concrete has set, the sleeve 63 can be removed to provide a gap for removal of the access cover 64. Alternatively, the sleeve 63 may be retained as a seal to prevent moisture ingress and condensation.

Preferably a plurality of individually switchable and uniquely identifiable antennas are embedded in the concrete pile base structure, preferably including an additional radio module antenna assembly 60 in the housing 61, and possibly one or more antenna assemblies 62, or other forms of antenna assemblies as defined above. Preferably, the antenna is capable of automatically identifying which antenna position in a receiving system provides the best signal strength in a round robin (round robin) fashion, and retaining the next highest data bandwidth handling capability based on the physical location of the receiving system. Then, for all subsequent data communications, only this antenna (location) is selected and active. To optimize performance, power is not distributed to unused antenna locations during data acquisition. If the signal from the selected antenna may be lost during data acquisition, the system may attempt to automatically establish a connection with one of the remaining antennas.

The antenna selection threshold is preferably determined based on the correlation of the received signal strength signal (RSSI), link quality and calculated test signal transmission bandwidth. The particular communication protocol used to select and enable the antenna may be selected based on the particular system and application being used. However, generally, only the antenna with the best transmission performance is selected and powered. Once selected, full system power will be delivered to the selected antenna to extend system battery life while providing optimal signal strength and highest bandwidth. Also, because the antenna structure is exposed on the surface of the pilings, the use of multiple antennas provides multiple recovery options at the expense of a single antenna.

Referring now to fig. 19, antenna elements 60, 62 are shown within the pilaster form 14. The upper antenna element 60 preferably floats in the concrete above the strands 12 to prevent any moisture sources from entering and reaching the strand structure after manufacture. The lower antenna 62 may be located at the bottom of the form, flush with the bottom surface, and positioned by the weight of the poured concrete. Other antenna component forms described above may also be used. The antenna may also be placed on the opposite side walls of the piling form 14.

A problem encountered with the sensor arrangement shown in figures 1 to 3 is that during concrete pouring and subsequent setting by a vibrator or other means, potential damage to the sensor is increased by the sensor being embedded horizontally on or between the strands 12 in the large cross-section through or throughout which concrete must be poured and/or tamped.

As shown in fig. 20, in accordance with the present invention, a U-shaped bar suspension assembly 120, 120' is preferably provided in the pile form 14 in a substantially vertical manner to facilitate quick, accurate, and repeatable positioning of the sensor. Preferably, this includes an accelerometer 122 and a strain gauge 124 that must be placed laterally within the pile core. The U-bar suspension elements 120, 120' are preferably spring-loaded and allow the sensor to be repeatedly positioned in the centre of the core area of the pile form without the need for additional manual measurements, whilst maintaining the accelerometer in a position perpendicular to the length of the pile to enable accurate acceleration measurements during subsequent driving into the pile and whilst maintaining the strain gauge in a position parallel to the longitudinal axis of the pile to ensure accurate strain measurements.

Referring to fig. 21 and 22, a first embodiment of the U-shaped bar suspension assembly 120 will be described in detail. The U-shaped bar suspension assembly 120 includes upper and lower U-shaped frames 126, 128. The legs of the lower U-shaped frame 128 can slide within the legs of the upper U-shaped frame 126. Springs 130 are positioned in the legs of the upper U-shaped frame 126 and bias the upper U-shaped frame 126 away from the lower U-shaped frame 128. An associated upper baffle/catch 132 and one or more lower catches 134 are attached to the upper and lower U-shaped frames 126, 128, respectively. The baffle/hook 132 and the hook 134 may be made of any suitable material to avoid galvanic corrosion and may have any suitable shape to engage the strand 12 when the U-shaped bar assembly 120 is disposed substantially vertically on the pile base exterior 14, as shown in fig. 22. The upper dam/catch 132 is preferably wide enough to prevent damage to the measuring instrument/sensor assembly during concrete casting and subsequent vibration setting/tamping.

To provide for this, the U-shaped bar suspension assembly 120 can be inserted between the strands 12 with the lower hook 134 engaging a lower strand 12. The U-bar suspension assembly 120 is then pressed in by pressing downward against the force of the spring 130 into the upper frame, so that the legs of the lower U-frame 128 are telescopically received into the legs of the upper U-frame 126. Once the force of the upper U-frame 126 is released, the upper and lower U-frames 126, 128 are deflected away from each other by the spring 130 and the hook portion of the upper retainer/hook 132 engages the underside of the upper strand 12 in the pile form 14.

Referring again to fig. 21 and 22, the U-shaped bar suspension assembly 120 further includes a placement sled 136 connected thereto. The placement sled 136 preferably includes a guide flange 138, the flange 138 contacting the legs of the upper and lower U-shaped frames 126, 128 to secure the mounting platform. The upper portion of the placement sled 136 preferably includes an extension 137, the extension 137 being bent into a generally U-shape to hold and protect an electronic module 159, as shown in fig. 22. Alternatively, this may be a separate piece or part of the electronic module housing.

Preferably, a center spring 140 is provided having a first end connected to the upper U-shaped frame 126 and the lower U-shaped frame 128. The second end of the center spring 140 is connected to the bracket 141 on the upper and lower sides of the placement sled 136 and biases the placement sled 136 to a substantially central position regardless of the distance between the clasps 132, 134 in the position of placement on the strand 12. The brackets 141 are spaced so that the measuring instrument/sensor assembly will be located substantially at the center of the pile foundation, preferably equally spaced "a" from the centerline of the mounting location of the measuring instrument/sensor assembly. As shown in fig. 22, the force vector of the center spring 140 has a major Y-direction component. However, depending on the inlay device, it is also possible to provide an X-direction component to hold the placement sled 136 against the U-shaped frame members 126, 128. The center spring 140 ensures that the placement skid 136 is in a repeatable center position after placement without requiring the placement person to climb down between the strand and the device to make position adjustments of the placement skid 136. The center spring 140 has a lower spring that is fixed relative to the spring 130. Once the suspension assembly is positioned, the placement skid 136 can be clamped and/or maintained in the central position using wire ties, throat clamps, thumb screws, or other similar devices. This prevents concrete and/or subsequent vibration/setting from moving the placement skid 136 away from the spring equilibrium position.

Alternatively, other spring arrangements may be used, or the central spring 140 may be omitted and the mounting platform provided on the U-shaped bar hanger assembly 120 by cable ties, bent wires, or other suitable fasteners such as those mentioned above.

A mounting platform 139 is preferably attached to the placement sled 136 using cable ties, wire ties, or the like. The mounting platform 139 preferably registers whether the placement sled 136 is positioned using alignment holes, protrusions, or other similar means. The accelerometer assembly 122 is preferably attached to the mounting platform 139 with a cable tie or other suitable connector form such as a mechanical fastener, epoxy or other suitable means. Alternatively, the damascene platform 139 may be omitted and its damascene features integrated with the placement sled 136.

Referring to fig. 23 and 24, a second embodiment of the U-shaped bar suspension assembly 120' is shown. The second embodiment 120 'is similar to the embodiment 120 except that the spring 130 is omitted and the mounting platform 139 is omitted, the mounting platform 139 functioning in conjunction with the segment having the placement sled 136'. In the U-shaped bar suspension assembly 120', the U-shaped frames 126, 128 can slide together or apart in the manner discussed above. However, the lower U-shaped frame 128 includes a series of holes on its legs that can be aligned with holes in the legs of the upper U-shaped frame 126 and associated with pins 133. the pins 133 can be pins, bolts, rivets or any other suitable fastener. The U-shaped frames 126, 128 may be adjusted for the particular strand 12 to be spaced from the pile foundation 10 being formed. The bolt pin 133 is then set. The bottom clasp 134' is formed of spring steel or other suitable resilient material. During set-up, the U-shaped bar suspension assembly 120 'is inserted between the strand 12 and the lower spring catch 134' that engages the lower strand. The spring clasps 134' are resiliently deflectable to allow the upper clasps 132 to be inserted under the desired upper strands 12 in the form 14 and then resiliently deflect the upper clasps 132 into engagement with the upper strands. The strands themselves also provide some degree of resilience and can spring out of position to allow the U-bar suspension assembly to be set up. The holes in the lower U-shaped frame 128 feet may be positioned in place for known standard strand locations for most known pile sizes. The placement sled 136' with attached metrology instruments and sensors may be attached to the center of the U-shaped frames 126, 128 using cable ties, clamps, rivets, or any other suitable fasteners.

As shown in fig. 26, the accelerometer assembly 122 preferably includes a housing 142 that maintains a water-tight cavity in which the physical accelerometer device is supported. The housing 142 is preferably formed of a top housing portion 144 and a bottom housing portion 146 that define a cavity 148 in which the physical accelerometer device is disposed. An O-ring 150 is located in the peripheral groove of the upper housing portion 144. Once the physical accelerometer device is positioned behind the pocket 148, the top and bottom housing portions 144, 146 are assembled, preferably with an adhesive securing the portions 144, 146 together. The top and bottom housing portions 144, 146 for the accelerometer housing 142 are preferably made of a low cost polymer material such as polycarbonate resin. A channel 152 is preferably formed around the perimeter of the housing to allow for physical alignment and nesting on the placement sled 136' or the nesting plate 139, if provided separately, with a cable tie in the channel 152, as shown in fig. 22-25.

As shown in fig. 21, an opening 154 is preferably located in the mounting plate 139 in which the accelerometer housing 142 is secured. The opening 154 has a V-shaped sidewall for registration/alignment so that the accelerometer housing 142 can be securely and accurately positioned with the peripheral edge of the housing 142 registered by the V-shaped sidewall. Slots are also preferably provided in the mounting plate 139 to allow the cable bundle to extend for attachment of the accelerometer. The opening 154 also allows concrete for the pile to be formed around the accelerometer element 122 in the housing 142 to ensure that the accelerometer collects the correct data. Alternatively, as shown in FIG. 24, the same type of opening 154 'is located directly in the placement sled 136' to allow for the nesting of the accelerometer assembly 122 in the same manner.

The strain gauge 124 is also preferably located on the placement sled 136' or the mounting plate 139, if provided separately, pre-assembled with cable ties. As shown in fig. 21, it is preferable to provide an opening 156 through the setting plate 139 in the area of the strain gauge 124 so that concrete for the pile can be formed around the strain gauge 124 to ensure that the strain gauge 124 can collect the correct data. In the embodiment shown in fig. 23 and 24, a similar opening 156 'is also provided directly in the placement sled 136'.

An electronics module 159 for the strain gauge 124 and the accelerometer is also preferably attached to the placement sleds 136, 136', as shown in fig. 22 and 24. Alternatively, this may be placed in addition to the pile base profile 14.

The damascene plate 139 is preferably formed of a polymer material, such as Lexan^TMOr any other suitable polymeric material. The upper and lower U-shaped frames 126, 128 are preferably fabricated from metal rods, tubes, or other structures, and the clasps 132, 134 are preferably fabricated from a suitable metal material, preferably steel, and are connected to the upper and lower U-shaped frames 126, 128 by welding, riveting, or other suitable means. The clasp 134' is made of a spring steel material or suitable resilient material as discussed above. The placement rails 136, 136' are preferably made of a suitable metal material such as steel.

The use of the U-shaped bar suspension assemblies 120, 120' enables quick and simple placement of the associated pile strands 12 as sensors such as a strain gauge 124 and accelerometer assembly 122 in a robust and repeatable manner whilst maintaining a precise alignment and positioning so that the accelerometer is perpendicular to and within the length of the formed pile core and the strain gauge 124 extends axially parallel to and within the length of the formed pile core. The U-shaped bar assemblies 120, 120' are designed to provide accurate mechanical registration of the measuring instrument/sensor assembly on the long sleds 136 by accurately positioning the strands 12 in the pile form 14 based on the strand position to ensure accurate and repeatable placement of the measuring instrument/sensor assembly, preferably centrally in the pile core.

Fig. 27 shows the position of sensor 16 in the piling 10, and also shows the position of the antenna/radio 60 and antenna element 62. A single cable 170 extends between the top sensor 16 and the housing 61 for data transmission within the piling 10. The sensors 16 are preferably positioned using the U-bar suspension assemblies 120, 120' or any other suitable system to keep them between the strands 12. By placing an antenna on the opposite side, it is always able to receive a radio frequency signal from the pile foundation regardless of directivity.

Fig. 28 shows an alternative preferred arrangement of sensors and signal transmission system for the piling 10. A bottom end sensor assembly 16b, which preferably includes an accelerometer element 122 and a strain gauge 124, is located near the top end. At least one antenna 18 is located near the top of the pile, and another sensor package 16a is preferably located at or near the top of the pile. It is also possible to indicate the preferred location of the top or bottom sensor packages 16a, 16b depending on the size of the piling. Preferably, the bottom sensor assembly 16b includes a non-volatile memory (NVRAM) that stores pile life history data, metrology tool calibration data, and other pile driving related data. This may be included in the electronics module 159 or otherwise placed.

The sensor package 16a, 16b preferably includes one of the U-shaped bar suspension assemblies 120, 120' to provide for maintaining the accelerometer element 122 and the strain gauge 124, which must be placed in the pile core, as does the conditioning electronics 159. The U-shaped bar suspension assemblies 120, 120' provide a faster and easier nesting function of the sensors 16a, 16b, reducing assembly time and cost.

In the preferred embodiment shown in fig. 28, a tube 230, preferably made of plastic material, extends between the bottom sensor package 16b and the electronics module housing 61 of the antenna/radio assembly 60. The cables or wires 231 extending between the bottom sensor assembly 16b and the electronics module housing 61 are disposed through the barrel 230, as shown in FIG. 29.

Fig. 30 shows a structure of an apparatus not including the pile foundation 10. An enlarged area or reservoir 233 for an excess of wires or cables 231 is located near or at the bottom end sensor assembly 16 b. The enlarged region or reservoir 233 may also be located at the rearward end of the barrel 230 in a ball-type fashion and sealed with wires or cables 231 extending toward the sensor assembly 16 b. This allows excess wires or cables 231 to be pulled out of the cavity 231 to be correlated in the event that the top of the pile foundation 10 is cut away after installation, so that the accelerometer and strain gauge instruments 122, 124, including any other sensors located in the bottom sensor suite 16b and/or non-volatile memory (NVRAM), can still be connected to a network monitoring node for continuous monitoring, as will be described in further detail below. In addition, all data stored in memory and used for the sensor conditioning electronics 159 in the bottom sensor package 16b may also be accessed.

Preferably, the tube 230 is loosely tied up to the strands 12 below the piling 10 using cable ties or other suitable connectors, as shown in fig. 28 and 29, so that the tube 230 is substantially maintained in this position but is not fully clamped and the cable or wire 231 can slide within the tube 230.

Referring to fig. 31, there is shown a schematic representation of a pile 10 illustrating the common data backbone in the form of the cable 170 or 231. In accordance with a preferred system overview of an embodiment of the present invention, wireless coupling devices, either via fiber optics, radio frequency, magnetism, or a hard connection, are located at the top and bottom of the stacked (or combined) vertical concrete pilings, which register as transceiver modules 260. This may be provided as a buried receiver module at the top of each pile and a buried transmitter module at the top, with common data connection through a hard wire link or backbone moving from the top of a pile to the top in a pass-through mode. Alternatively, the transceiver module 260 may provide a bi-directional data depending on its particular application.

With this apparatus, data can be relayed and transmitted for monitoring in connection with driving a pile from or through a pile under a surface. This allows information (data) collection from different embedded sensing modules in the pile to also be commonly connected to the hard-wired backbone. Preferably, a method of identifying the source of the transmitted data is provided, for example, in the network node.

In addition, according to the present invention, a special provision of the same interface, power between the related structures, can be used. This would provide an automatic distribution of internal power sources in the event that sufficient operating current is not available. Due to the (sometimes very remote) operating location, the power source for all structures may also include solar energy obtained using solar panels.

Alternatively, it may provide an auxiliary backup port that is capable of connecting to an auxiliary power source, such as a battery in the event of a failure of an internal power source. External plugs or connections for reading data directly from the accelerometers, strain gauges, temperature sensors and any other sensors through a hard wire backbone buried in the concrete structure may also be provided in the event of a failure of an internal data recorder, signal conditioner or transmitter, so that data from sensors and gauges in the concrete structure may still be collected in the event of a partial system failure.

Central inductive data multiplexing and control including radio interface electronics is preferably provided in the housing 61 or another housing located in the piling, preferably with an access cover located on the surface of the piling.

A pile-base identification, preferably corresponding to a radio address or Media Access Control (MAC) address for the transmitter, is stored in the memory along with data for the data product, the calibration data and sensor details, sensor configuration, gain, offset, metrology tool coefficients, sensitivity, numbering, serial numbers, vendor, etc., and data for verification of system Quality Control (QC). This initial information is preferably stored in non-volatile memory (NVRAM) located in the top measurement conditioning electronics and is additionally added to the memory during pile manufacturing at the casting plant by adding information about the pile foundation such as casting plant, inspector name/number, casting data, pile foundation casting location, concrete mix, concrete specific gravity, pile foundation length, diameter and other geometries, temperature profile (described in more detail below) and/or preload strain, which may be used later. Any casting data or other historical data relating to the formation of the pile may be recorded and therefore assisted in the subsequent driving process. The memory is preferably accessible by the pile leader for radio testing and/or inspection prior to or during subsequent casting to allow Quality Control (QC) to be achieved and any repairs required prior to shipping and/or driving into the pile. The cast plant inspector may also enter key inspection parameters that can be accessed and used during driving of the pile foundation.

All data from the memory may be accessed by radio frequency transmissions from the pilings using antenna elements 60, 62 located on the pilings or other types of antenna elements as mentioned above.

Once at a set location, if available, Global Position System (GPS) location information for the pile foundation, possibly at the time of driving, is entered into the memory. This may be coupled to a known soil property map to verify and/or determine soil properties using the driving data (and utilize the soil survey portion of the driving pile function) and/or modify the driving process.

Strain and force data collected by the strain gauge 124 and accelerometer 122 during driving of the pile may be transmitted by one of the antenna elements 60, 62 via Radio Frequency (RF) for dynamic monitoring during the entire driving of the pile. Thus providing critical absolute internal strain information during the drive versus relative strain externally monitored during drive in a previously known manner. In particular the invention is able to monitor the actual conditions and use this information to ensure that the driving force does not exceed the level at which undesirable tension conditions are created in the pile. The absolute pressure and tension stress information is preferably used to provide real-time feedback to the hammer or crane operator to selectively control hammer energy and optimize the driving process. This information can also be reported and provided with feedback allowing absolute strain readings and ranges to avoid over-driving and subsequent pile failure.

The inspection data, impact data, any re-strike data and the maximum stress may also be recorded in the memory. This data may then be acquired or tracked for each pile and a unique time may be printed or tracked in the memory in a similar manner to actively read/write a Radio Frequency (RF) Identification (ID) tag that can receive and store data as well as transmit data. In addition, the drive inspector, civil engineering inspector and pile foundation drive crane operator may also access the sensor unit electronic memory data during driving to check for information that is verified about the pile foundation and its history. All of these pile history data will be linked to the actual drive-in data header and can be transmitted with the drive-in data to a pile database for further life cycle and/or long term monitoring. Quality assurance/quality control (QA/QC) has the capability to be traceable and declarative. In addition, this data can be used in conjunction with future analysis and comparisons to predict the occurrence of failures or damage.

Thus, the full life cycle of the pile is recorded in the non-volatile memory (NVRAM) and can be accessed via Radio Frequency (RF) transmission using at least one of the lines 60, 62. In addition, in the event of an antenna failure, the housing cover 64 may also be accessed from the surface of the piling 10 to provide a manual electrical connection and/or to perform battery or drive replacement of the sensor unit electronics module, if desired.

The memory is preferably a non-volatile memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), or other writable optical or magnetic medium, and is preferably accessed and controlled by a controller. It is also possible that the memory is an expanded memory module for interfacing with a known Radio Frequency (RF) Identification (ID) module. Preferably, the sensor unit electronics includes a non-volatile memory (NVRAM) capable of capturing information about the sensor and other information about the formed pile. This is used to connect the life cycle of the pile with its associated data.

According to the invention, the concrete strength and preparation can be checked through the concrete structure temperature or curing curve. Many standards specify this process (astm c 1074). Temperature curing curves may also be stored in the sensor unit electronic memory by providing temperature sensors on the pile core and its outer surface. Given that the thermal curing temperature streamlines only radiate outwardly from the pile core and remain constant at the same point along the length of the pile, this data can be accurately tracked using the core and surface temperature sensors to determine a differential temperature gradient in the pile and thus when the concrete has reached a workable strength.

Software may also be used to collect information from the sensor electronics and data logger and present it to the user based on various rules established, for example, by the casting pilot, factory inspector, driver inspector, crane operator, etc. The systems are preferably configured to support each other. For example, the civil engineering inspector may set the system to flag the pile driving inspector when a particular operating (strain, stress, load, etc.) range is exceeded. This may also be provided to the jack operator or other user to ensure that a particular driving threshold is not encountered, or that notification of an error flag is made. The system may also track, calculate and transmit hits based on a threshold.

In addition, by placing measurement instruments at a known distance from the top and top of the pile, the irregular wave velocities can be detected using the relevant data features and used to compare certain predetermined problem conditions, such as excessive strain, wave reflections caused by material discontinuities such as a fractured pile. When such irregularity or a potential irregularity data generation is detected, the operator can be notified.

In a preferred embodiment, the accelerometer is associated with a controlled Alternating Current (AC) coupling or Direct Current (DC) offset servo motor to offset the zero offset effect typically present in piezoelectric accelerometers. In the Piezoelectric (PE) accelerometer application of the present invention, the following known application-specific conditions apply:

the pile foundation always starts at a speed equal to zero.

-the measured events have a total cycle time of less than 200 milliseconds.

The pile foundation always returns to a speed equal to zero.

Because the velocity before and after the measured event is equal to zero and the measured event occurs at a predetermined known time interval, the use of Alternating Current (AC) coupling or fixed Direct Current (DC) offset is controlled using a servo motor control feedback near the zero offset effect (or error) common in Piezoelectric (PE) accelerometers prior to data capture for the purpose of adjusting the accelerometer signal. This will provide better quality accelerometer data.

By using the invention, the kind history of a pile foundation and the driving data thereof can be monitored and recorded. Although the invention makes specific reference to captured accelerometer and strain gauge data during driving, these are preferred forms of data, and other forms of sensor may be used to capture and provide other forms of data, such as a top temperature sensor recording temperature during driving, or bottom and top temperature sensors tracking the temperature gradient of the pile. Other sensor forms may also be used.

Although it is preferred to use a long life battery in conjunction with the sensor unit electronics and memory, it is also possible to provide other sources of power, such as vibration induced current, solar power, or other devices. In addition, access to an additional external power source to replace the internal power source may also be provided.

It is also possible according to the invention to multiplex and control the central sensing data comprising the radio interface electronics for recovery by means of the housing cover 64. However, the sensor measurement instrument will remain embedded and unrecoverable in the system at all times. This will further reduce the cost of the system by providing a recovery device that reuses part of the system.

Referring now to fig. 32, where the top of the pilings 10 is not cut away, the pilings 10 are designed for long term monitoring by removing the radio module from the electronics module housing 61 of the antenna/radio 60 according to the present invention. A replacement and external power network monitoring node 314' is then provided in the housing 61 and connected to any available top/top metrology instrument cable or wire 231.

Referring now to fig. 33, there is shown the pile foundation 10 after driving, the pile foundation 10 having a pile top removed to a cut-out height according to the application requirements. To provide additional monitoring of the life cycle of the piling 10 and its subsequent structure or infrastructure, and to enable access to the information in the memory of the bottom induction kit 16b, the wires or cables 231 can be pulled from the storage 233 after the top of the piling is cut off, and can be associated with a connector or cable connected to a network monitoring node 314, which can be embedded in a capping structure, or located near the piling 10. This can be done using a field technique. Accordingly, if the piling 10 is driven into and cut off the top thereof, regardless of whether this occurs below the top gauge 16a, the cross-section of the tube 230 containing the cable 231 is always exposed, as shown in fig. 33.

Referring now to fig. 34A, B, C and 35, pile life cycle monitoring according to the present invention is provided. This may be accomplished by utilizing a respective pile antenna/radio 60 retrofit action with network monitoring node capability. This provides a method for establishing a power local area network that selects the sensor validation pilings 10 and other sensors. As shown in fig. 35, the retrofit nodes or data ports may be located in the electronic module housing 61 prior to casting the concrete cap 350 and include mechanisms for self-configuring the pile foundation and all connecting pile foundation nodes in the concrete structures that make up the transportation/construction foundation and building. The nodes or data ports are preferably interfaced using a network communication protocol. In addition, the power distributed by the system to all of the metrology instruments/sensors is also monitored. Alternatively, the power distribution and network functions may be correlated.

According to the present invention, constructors will retrieve or add existing pile data ports in the electronic module housing 61 using a wired network that provides wired connections for power and data transfer. The nodes added to the network are preferably self-configured and reporting in a point-to-point or master-slave configuration. The network and/or wires provide redundancy and addressability to ensure that at least a subset of the stub bases are available and/or accessible.

These new infrastructure 10 forming the basis may be connected to a larger network or telemetry uplink 312 such as the integrated packet radio service (GPRS), wired broadband, wire line network, etc., as shown in fig. 35.

Historical life information about each pile 10 (including dynamic setup details/results) will be transmitted locally by the pile 10, while the bottom sensor suite 16b now provides long-term monitoring.

All uploaded telemetry information from the apparatus for long term monitoring of the pile foundation 10 is stored in a remote central repository for inspection, monitoring and reporting.

The system also provides means for retaining the unique address information of a given radio, preferably logically linked to the sensor address Identification (ID), or through other synchronization or mapping means, to replace the radio Identification (ID) with the backbone Identification (ID) of the replacement network monitoring node 314

The connectivity of the current pile sensors 122, 125 connected to the network monitoring node 314 is achieved using low power differential signals for the pile foundation 10. Although more tolerant to radio and material interference, the use of a digital signal structure will better eliminate any possibility of interference and decoupling the radio/monitoring module from the power converter transfer function. According to the present invention, a digital bus structure will be used for all sensors used in the system. In this configuration:

-sensor details and calibration information are maintained in the top sensor conditioning electronics, the digital bus providing a means for sensor calibration and sensor data to communicate with all non-volatile memory (NVRAM);

a shared bus is used to enable the plurality of metrology instruments and the plurality of uniquely identified metrology instrument types to share the same physical wired backbone.

A high speed and power efficient bus protocol for handling the data volume from each measurement instrument;

a smart plug-and-play system is used to enable the automatic identification and self-configuration of the majority of the measuring instruments used, according to the current measuring instruments;

in the case that the radio/monitoring module 60 must be removed, the instrumentation setup/calibration and the pile life history are retained or reflected by the electronics with the bottom sensor 16b (such as non-volatile memory (NVRAM)) for continued use by the replacement network monitoring module 314.

The present invention provides long-term monitoring capability via the overhead metrology data and data stored in the conditioning electronics non-volatile memory (NVRAM), regardless of the final pile configuration. In addition to enclosing the network monitoring node 314 within the lid 350, strain gauges and other sensors may also be located within the lid 350 and connected to additional network nodes for lid gauges and sensors. Additional monitoring capabilities may also be provided as shown in fig. 35, for example, for monitoring other structures such as piers or foundations located on the cap 350. These additional monitoring capabilities may be performed by providing nodes with self-adapting network capabilities. Thus, monitoring of all nodes in a given structure may be performed through the use of a stackable network topology built upon the foundation pile monitoring system described in detail herein. This provides a system or structure in which the pile sensors have been secured with other sensors in a cover which is then secured with other sensors in a pier which is then secured with other sensors in the subgrade and finally provides data for a partially or fully integrated structure (including one or more of the elements mentioned and/or other structural elements) via a telemetry link.

Referring now to fig. 36, an improved apparatus for determining the depth of penetration of a pile foundation and the ultimate bearing capacity of the pile foundation in accordance with the present invention is provided. Current devices for determining the pile penetration depth (and ultimate capacity) of a pile involve having to manually place marks on one side of the pile, and an inspector must be responsible for counting the pile drop (via pile counter) and noting the movement/penetration of these marks through a height reference mark. This process requires full human effort and involvement in the driving process. The present invention allows for automatic and accurate hammer counting via stimulation beyond a set threshold in the Pile interior, or via signal measurement instruments 122, 124 received and interpreted by a tracking/monitoring device such as Pile work Station (SPW)320, a central system controller that collects real-time driving data from sensors and measurement instruments in the Pile 10, which can interface with the highest sensing Pile penetration system, track the number of shots (internal or external), and use dynamic data collected during Pile driving to count and synchronize the shots per unit displacement to communicate information with the inspector in real time to control the driving and provide real-time Pile bearing capacity data.

Tracking the displacement of the pile foundation 10 according to the present invention may also be performed by one of many other methods.

In a first method, laser radar time of flight (time of flight) and triangulation are associated into a pile foundation workstation (SPW) 320. In this configuration, a laser radar system 322 first projects elevation to a reference height relative to a vertical fixed pile foundation 10 to determine the adjacent side A of a right triangle. The lidar 322 then transfers a vertical pin base to a reference point 324 near the top of the pile foundation 10 to determine the relative hypotenuse C of the right triangle. The vertical height of the pile 10 above the reference height is determined by the distance B from the reference height to the reference point 324, the reference point 324 being a known distance X below the top. Knowing the overall length of the piling 10, and the dynamically calculated distance B from the distance X, the piling penetration depth P below the reference height can be simply calculated. The change in height can also be determined simply by a change in C.

Reference mark 324 at the top of the pile 10 will be used to facilitate automatic vertical tracking of a vertically fixed pile and (motorized servo motor control system) self-alignment adjustment by the rotating radar head. A retro-reflective line or mapping object may be used.

As the pile foundation is driven, the radar system 322 will continue to compensate by locking the reference mark 324 for downward movement of the reference mark target. The system dynamically provides data on the original real-time calculated pile height, or the calculated pile penetration depth P, to a tracking monitoring device, pile work Station (SPW) 320. This is used along with the number of hits derived by the internal metrology instrumentation system to calculate/record/track the hits/movements to provide a complete automatic tracking.

Instead, the radar is projected to a common point at the top of the pile 10, which involves the possibility of placing the reference mark on the hammer or cover after the distance perpendicular to the fixed pile (length) surface is obtained at the reference height. The penetration depth is continuously determined by subtracting the reference height (determined by trigonometry) from the total pile length L to measure the pile height. It is preferable to use a vertical reset scanning system (in the case of vertically extended pilings) to handle successively shorter heights. The system may also scan from the top to the bottom of the pile to determine the angle of the fixed pile, not vertically to a point at the reference height of the pile, and then determine the required data using known trigonometric counts. This may also be relevant in pile work Stations (SPW)320, in place of the need for an inspector to physically collect pile driving data. The pile foundation workstation (SPW)320 calculates or keeps track of the shots and synchronizes this data to pile foundation penetration data, and then calculates the shots for each displacement based on the calculated pile foundation penetration depth P.

Alternatively, an infrared-based time-of-flight charge transfer measurement system sensor may be used to detect and reference the center of the hammer or predetermined point on the pile such as the pile cushion by thermal imaging. In addition, a rotating camera system using three-dimensional image sensing and pattern recognition can also be used as a target recognizer instead of the radar head referred to above.

A second method of determining the penetration depth of the driven pile is through the use of an air pressure altimeter, as shown in fig. 37. Two barometers 340, 342 provide two sides, each including a barometric pressure and a height. Generally, when measuring height, the altimeter can be used for a short period after calibration, and constantly performs zero-output calibration of changes in air pressure due to changes in weather conditions. Some systems may obtain information from global position measurement system (GPS) satellites, which do so at known barometric pressure differences. According to the present invention, a digital gas pressure altimeter is mounted (by separate communication) on the pile 10 or the hammer or the cover, preferably removably mounted on the electronic module housing 61 and engaged with one of the wireless digital channels. The height B is then determined by comparing the difference in data transmitted from the pile or the hammer insert altimeter 340 with another altimeter embedded below the fixed reference height (or other known height), such as the altimeter of the previous pile depth mark string. The difference in the outputs of the altimeters 340, 342 is measured and effectively removes the same directional or absolute air pressure from the equation and provides a purely differential local altitude or relative air pressure reading during the drive. The raw data is preferably collected using a monitoring device 344, the monitoring device 344 receiving signals from the two altimeters 340, 342 in a manner similar to that described above. The height is then provided by the altimeter or calculated in the pile work Station (SPW) 320. Preferably, the altimeters 340, 342 are calibrated to each other at the same height before using zero output to tolerate errors. The altimeters 340, 342 may communicate with the monitoring device 344 using wireless or wired connections and/or may directly utilize the pile foundation workstation (SPW)320 using a radio/antenna assembly 60, which radio/antenna assembly 60 is used for a separate wired or wireless connection of the pile foundation mosaic altimeter 340 with the reference altitude altimeter 342 depending on its location. The floor altimeter 342 may be located away from the pile foundation 10 in the operating position as long as the reference height is maintained.

Although these methods assume that the pile is driven in a direction coaxial to gravity, in the case of a tilt pile, corrections and adjustments can be made through tiltmeters and trigonometry. For pilings which generally have high lateral load, they are typically driven at an angle of up to 45 ° (inclined pilings). In this case, the compensation angle is preferably determined using the tilt, while the penetration depth is calculated using known trigonometric techniques.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the specific embodiments described above, which are provided as examples. Other modifications and extensions of the present invention may be made and all such modifications are considered to be within the scope of the present invention as defined by the appended claims.

Claims (21)

1. A method of monitoring a pile foundation, comprising:

inserting a sensor sleeve between the strands or reinforcements in a pile form to place the sensor in a core region of a pile;

connecting a radio module to the pile foundation, the radio module in communication with the sensor suite;

casting the pile foundation;

driving into the pile foundation and obtaining data from the sensor package during driving;

monitoring data from the sensor package during driving and at least one of monitoring and using the data during driving to adjust driving parameters for the pile foundation; and

absolute internal strain information from the data obtained from the sensor package within the pile core is used to maximize driving performance in real time during driving of the pile.

2. The method of claim 1, further comprising:

the absolute internal strain information is monitored to ensure that the driving force does not exceed a level that creates an damaging tensile stress condition in the pile foundation.

3. The method of claim 1, further comprising:

monitoring the absolute internal strain information to change preload during the driving; and

this information is used to predict pile foundation failure.

4. The method of claim 1, further comprising:

the sensor package is inserted into a top end of the pile foundation and a second sensor package is inserted into a top portion of the pile foundation.

5. The method of claim 1, further comprising:

detecting irregular wave velocities using the data and a known distance between the sensors in the pile foundation; and

the irregular wave velocity is compared to a predefined condition for failure detection.

6. The method of claim 1, further comprising:

data from the sensor package is stored in a memory.

7. The method of claim 1, further comprising:

the data obtained is transmitted to a pile history database for further life cycle and long-term monitoring.

8. The method of claim 1, further comprising:

retrofitting the pile foundation by providing a network monitoring node connected to the sensor suite;

the specific address information of a known pile foundation is reserved by logically linking a sensor suite address identification; and

the node is connected to an external gateway for long-term monitored data transmission.

9. The method of claim 7, further comprising:

cutting off a top of the pile foundation; and

excess wire or cable located within a hollow tube is pulled from a wire reservoir adjacent a top end of a pile to connect the sensor suite located at a top end of the pile to the network monitoring node.

10. The method of claim 1, further comprising:

the position of the sensor assembly is fixed using a spring loaded support member having a U-shaped frame that is inserted generally vertically into the pile form and resiliently engages at least two opposing strands via an outward spring force.

11. A method of long term monitoring of a pile foundation, the method comprising:

forming a cast concrete pile foundation having a sensor package located in a core region of the pile foundation;

driving into the pile foundation and obtaining data from the sensor package during driving;

retrofitting the pile foundation by providing a network monitoring node connected to the sensor suite;

the specific address information of a known pile foundation is reserved by logically linking a sensor suite address identification; and

the node is connected to an external gateway for long-term monitored data transmission.

12. The method of claim 11, further comprising:

pile foundation data is stored in a memory located in the pile foundation.

13. The method of claim 12, further comprising:

for a pile foundation which is cut off at its top after driving, excess wire or cable located within a hollow tube is pulled from a wire reservoir adjacent to a top end wire or cable reservoir to connect a top end sensor package to the network monitoring node.

14. The method of claim 11, further comprising:

providing a global position determination system at the pile foundation;

obtaining a position of the pile foundation; and

the soil properties of the location are obtained.

15. The method of claim 11, further comprising:

providing a rewritable memory in the pile foundation; and

storing and updating data in the rewritable memory.

16. A suspension assembly for positioning at least one sensor between strands in a concrete structure, the suspension assembly comprising:

a first U-shaped frame and a second U-shaped frame connected to each other;

at least one strand engaging member located on each of the U-shaped frames offset facing each other and adapted to engage opposing reinforcing strands or rails of a concrete structure; and

a slidable shelf attached to the frame for supporting at least one measuring instrument.

17. The suspension assembly of claim 16 wherein at least one of the strand engaging members is formed of a spring material.

18. The suspension assembly of claim 16 wherein the first and second U-shaped frames are resiliently biased away from each other; and

a center spring extends between the slidable shelf and the frame to center the slidable shelf in the U-shaped frame, the slidable shelf including the provision of an additional sensor.

19. The suspension assembly of claim 16, further comprising:

a first opening having at least two opposing V-shaped sidewalls for registering a first induction housing located in the slidable shelf or a mosaic plate connected thereto; and

for a second sensor, a second opening is defined in the slidable shelf or the mosaic plate connected with the slidable shelf.

20. The suspension assembly of claim 16, further comprising:

a strand measuring instrument connected to the sliding shelf.

21. The suspension assembly of claim 16, further comprising:

an accelerometer connected to the sliding shelf.