CN108824838A - Prestressed concrete cylinder pipe external prestressing strengthening system and its construction method - Google Patents

Abstract

The invention discloses an external prestressed reinforcement system of a prestressed steel cylinder concrete pipe and a construction method thereof, comprising: a plurality of prestressed steel strands arranged on the outer wall of a prestressed steel cylinder concrete pipe, and a plurality of prestressed steel strands The first and last ends of the line are fixed on the anchor plate by anchors; each of the prestressed steel strands is fixed on an anchor plate by an anchor, and the prestressed steel strands are double-wound on the prestressed steel cylinder concrete on the outer wall of the tube. The invention can not only give full play to the high tensile strength of the prestressed steel strand, but also realize the decompression and non-stop water supply of the entire pipeline. The external prestressed reinforcement system acts on the surface of the prestressed steel cylinder concrete pipe structure without damaging the original The integrity of the pipe body structure of the stressed steel cylinder concrete pipe has a good reinforcement effect.

Description

External Prestressed Strengthening System of Prestressed Steel Tube Concrete Pipe and Its Construction Method

technical field

The invention relates to an external prestressing reinforcement technology of a prestressed steel cylinder concrete pipe (PCCP), which can be used for reinforcement of a prestressed steel cylinder concrete pipe with broken wires or structural cracks.

Background technique

Prestressed concrete cylinder pipe (PCCP for short) is composed of protective layer mortar, prestressed steel wire, concrete tube core and anti-seepage steel cylinder. The prestressed steel wire is the main carrier of internal pressure, and the concrete tube core is the main carrier of external load. Due to the influence of manufacturing, installation, operation, overloading and external corrosive environment, cracking and delamination of protective layer mortar, corrosion and fracture of prestressed steel wire, longitudinal cracking of core concrete and corrosion leakage of steel cylinder will occur in PCCP pipes. , affecting the carrying capacity and operating life of PCCP, and even a pipe burst accident. The invention provides an external prestressed reinforcement system of a prestressed steel cylinder concrete pipe (PCCP) and a construction method thereof.

Contents of the invention

The invention provides a method of arranging a plurality of prestressed steel strands along the outer circumference of the prestressed steel cylinder concrete pipe to be reinforced, and reinforcing the overall structure of the prestressed steel cylinder concrete pipe by applying prestress to both ends of the steel strands The external prestressing reinforcement system of the prestressed steel cylinder concrete pipe and its construction method.

In order to achieve the above object, the present invention provides the following technical solutions:

An external prestressing reinforcement system for a prestressed steel cylinder concrete pipe, comprising: a plurality of prestressed steel strands arranged on the outer wall of the prestressed steel cylinder concrete pipe, and the first and last ends of the plurality of prestressed steel strands Fixed to the anchor plate by anchors.

Further, each of the prestressed steel strands is fixed on an anchor plate through an anchor, and the prestressed steel strands are double-wound on the outer wall of the prestressed steel cylinder concrete pipe.

Further, two adjacent anchor plates are arranged alternately on the outer wall of the prestressed steel cylinder concrete pipe, and a plurality of anchor plates are arranged in two rows, and the two adjacent anchor plates connect to the prestressed steel cylinder concrete pipe body The included angles formed between the projection of the end face and the top position of the section and the center of the section are both 15°; an anti-corrosion sealing layer is provided on the outer side of the anchorage and the anchor plate as a whole.

A construction method for external prestressed reinforcement system of prestressed steel cylinder concrete pipe, comprising the following steps:

1) Reinforcing pipeline excavation and support;

2) Preparation for construction, cleaning up the construction area, setting up workbenches and safety enclosures;

3) System layout, base surface treatment, anchor end installation;

4) Ring through the steel strand;

5) Prestress tension and locking;

6) Anti-corrosion at the tensioned anchorage end;

7) Concrete surface protection, pipeline earthwork backfilling.

Further, the specific steps of the step 1) are: excavation of earthwork around the reinforcement pipe, when there are other pipelines around the reinforcement pipe, according to the relative position of the reinforcement pipe and the adjacent pipeline, determine the excavation safety distance, and at the same time, the soil on the side of the pipe monitoring of body deformation; when the safety distance cannot be determined, Larsen steel sheet piles are used to support and isolate adjacent pipelines to ensure that they do not slip laterally, and at the same time monitor the deformation of the soil on the side of the pipeline.

Further, the specific steps of step 3) are: determine the installation position of the prestressed system by measuring and setting out the line, and when the surface of the prestressed steel cylinder concrete pipe is damaged, use epoxy mortar to repair and level it; the anchorage of the prestressed steel strand The slabs are arranged crosswise on the upper part of the prestressed steel cylinder concrete pipe body.

Further, the specific steps of the step 4) are: before looping the steel strands, it is necessary to excavate a cable groove perpendicular to the axis of the prestressed steel cylinder concrete pipe at the bottom of the pipe body, so as to loop through the steel strands. The threading groove is divided into three parts along the length of the pipe. The principle of excavation is the two ends first and then the middle. During the excavation, manual excavation is mainly used to minimize disturbance to the soil foundation at the bottom of the pipe.

When threading, the steel strands should be adjusted in place according to the layout spacing, and should be tightly wound on the surface of the prestressed steel cylinder concrete pipe to be reinforced, and the anchorage end should be locked. After each threading groove is threaded, it needs to be backfilled with self-compacting concrete or special solidified soil.

Further, the specific steps of step 5) are as follows: divide multiple regions along the length of the prestressed steel cylinder concrete pipe body, and the prestressed tension locking sequence is to first select the middle region, followed by the regions at both ends, and then finish symmetrically in the remaining regions .

Further, the specific steps of step 6) are: after all the prestressed steel strands are stretched and locked, paint the surface of the tensioned anchor end in the prestressed reinforcement system with a 3mm-5mm thick anti-corrosion material for sealing treatment, and the anti-corrosion material For polyurea.

Further, the step 7) uses C15 concrete with a thickness of 100mm to protect the prestressed steel strand; before backfilling the pipeline earth, it is necessary to remove the sundries in the trench and remove the accumulated water, and it is not allowed to use it in the case of accumulated water. Backfill. Technical requirements such as backfill thickness and backfill shall be carried out according to the original design.

In the above technical scheme, the beneficial effects of the external prestressed reinforcement system of prestressed steel cylinder concrete pipe and its construction method provided by the present invention are: the present invention can not only give full play to the characteristics of high tensile strength of prestressed steel strands, but also can The entire pipeline can be decompressed without stopping the water supply, and the external prestressed reinforcement system acts on the surface of the pipe body structure of the prestressed steel cylinder concrete pipe, without destroying the integrity of the pipe body structure of the original prestressed steel cylinder concrete pipe, and the reinforcement effect is good. The external prestressed reinforcement system is convenient for laying, anchoring and tensioning, and the construction is quick. The durability of the external prestressed reinforcement system can be achieved by anti-corrosion treatment of the tensioned anchorage end.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings that are required in the embodiments. Obviously, the accompanying drawings in the following description are only described in the present invention For some embodiments of the present invention, those skilled in the art can also obtain other drawings according to these drawings.

Fig. 1 is a schematic structural view of a prestressed steel cylinder concrete pipe external prestressed reinforcement system provided by an embodiment of the present invention;

Fig. 2 is the front view of Fig. 1;

Fig. 3 is a side view of Fig. 1;

Fig. 4 is the structural representation of prestressed steel strand, anchorage and anchor plate in Fig. 1;

Fig. 5 is a schematic diagram of the connection structure of the anchorage and the anchor plate in Fig. 4;

Fig. 6 is a structural schematic diagram of the prestressed steel cylinder concrete pipe body in Fig. 1 .

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figures 1-6, a prestressed steel cylinder concrete pipe external prestressed reinforcement system according to an embodiment of the present invention includes: a plurality of prestressed steel cylinders arranged on the outer wall of the pipe body 1 of the prestressed steel cylinder concrete pipe Steel strands 2 , the first and last ends of multiple prestressed steel strands 2 are fixed on the anchor plate 4 through anchors 3 .

Each prestressed steel strand 2 is fixed on an anchor plate 4 through an anchor 3, and the prestressed steel strand 2 is double-wound on the outer wall of the prestressed steel cylinder concrete pipe body 1.

Two adjacent anchor plates 4 are arranged staggeredly on the outer wall of the prestressed steel tube concrete pipe body 1, and multiple anchor plates 4 are arranged in two rows by bonding glue, and the two adjacent anchor plates 4 are connected to the prestressed The included angle between the projection of the end face of the steel tubular concrete pipe body 1 and the top position of the section and the center of the section is 15°; the outer side of the anchor 3 and the anchor plate 4 is provided with an anti-corrosion sealing layer 5, and the anti-corrosion sealing layer 5 is anti-corrosion material.

The prestressed steel cylinder concrete pipe body 1 includes: a mortar protection layer 11, a prestressed steel wire 12, an inner concrete pipe core 15, an outer concrete pipe core 13 and an anti-seepage steel cylinder 14, and the anti-seepage steel cylinder 14 is embedded in the inner concrete Between the pipe core 15 and the outer concrete pipe core 13 , a mortar protective layer 11 is provided on the outer side of the outer concrete pipe core 13 , and a prestressed steel wire 12 is wound around the joint between the outer concrete pipe core 13 and the mortar protective layer 11 .

Specifically, the external prestressing reinforcement system of the prestressed steel cylinder concrete pipe is to arrange a plurality of prestressed steel strands 2 circumferentially along the outer surface of the prestressed steel cylinder concrete pipe body 1 to be reinforced, and the prestressed steel strands 2 The tension anchor ends of the prestressed steel cylinder concrete pipe body are arranged crosswise on the upper part of the prestressed steel cylinder concrete pipe body 1, and are located at the central angle of the prestressed steel cylinder concrete pipe body 1. The position is 15° and 345°, whichever is convenient for installation. By applying prestress to the two ends of the prestressed steel strand 2, external prestress can be used to reinforce the overall structure of the prestressed steel cylinder concrete pipe body 1, and the two ends of the reinforced prestressed steel strand 2 are fixed on the anchor by the anchor 3 plate 4.

Table 1 Main Mechanical Indexes of Steel Strand

Among them: 15.2mm is the diameter of the steel strand after peeling and washing oil, and the diameter of the steel strand with PE is 18.2mm.

Table 2 Adhesive technical performance indicators for bonding

Table 3 Performance indicators of anti-corrosion materials

project Performance Viscosity (MPa·s) ≥3000 Solid content (%) ≥80 Surface dry time (h) ≤6 Tensile strength (MPa) ≥15 Elongation at break (%) ≥300 Tear strength (N/mm) ≥40 Low temperature bendability (℃) ≤-40 Water impermeability (0.4MPa*2h) impermeable Bond strength (MPa) ≥2.0

A method for producing an external prestressed reinforcement system for a prestressed steel cylinder concrete pipe described in an embodiment of the present invention comprises the following steps:

1) Reinforcing pipeline excavation and support;

When the earthwork around the reinforced pipe is excavated, in order to avoid disturbing the adjacent intact pipe, it is necessary to cooperate with manual excavation; after the mechanical excavation is 1.5m away from the pipe, the rest of the earthwork shall be excavated manually. Before earthwork excavation, determine whether there are underground structures around the pipeline, and if necessary, mark its location and depth to prevent damage. After the precise positioning of the pipeline position, measure and set out the line according to the excavation position, and release the excavation foot and upper opening excavation line. If the pipeline consists of multiple pipelines, the safety distance for excavation shall be determined according to the relative position of the reinforced pipe and the adjacent pipeline, and the deformation of the soil on the side of the pipe shall be monitored at the same time. If the safety distance cannot be determined, measures such as Larsen steel sheet piles must be used to support and isolate adjacent pipelines to ensure that they do not slip laterally, and at the same time monitor the deformation of the soil on the side of the pipeline. Double-row prestressed steel cylinder concrete pipe external reinforcement excavation section and Larsen steel sheet pile support, pipe side soil deformation monitoring cloth.

2) Preparation for construction, cleaning up the construction area, setting up workbenches and safety enclosures;

3) System layout, base surface treatment, anchor end installation;

Determine the installation position of the prestressing system by measuring and setting out the line. If the surface of the prestressed steel cylinder concrete pipe body is damaged, it needs to be repaired and leveled with epoxy mortar. The anchor ends of the prestressed steel strands 2 are cross-arranged on the upper part of the prestressed steel cylinder concrete pipe body 1, and are located at the central angles of 15° and 345° of the prestressed steel cylinder concrete pipe body 1. The base surface needs to be ground and cleaned. Oxygen structural adhesive to fix the anchor plate.

4) Loop through the prestressed steel strand;

Before looping through the prestressed steel strand 2, it is necessary to excavate a cable groove perpendicular to the pipeline at the bottom of the prestressed steel cylinder concrete pipe body 1, so as to loop through the prestressed steel strand 2. The threading groove is divided into three parts along the length of the pipe, with a depth of 200mm. The principle of excavation is the two ends first and then the middle. The excavation is mainly manual excavation to minimize disturbance to the soil foundation at the bottom of the pipe.

The cutting length of prestressed steel strand is calculated using the following formula:

L＝π*D+2*L1+2*A1

In the formula:

D—the outer diameter of the PCCP to be reinforced;

L1—the working length of tension at both ends, each end is about 1m;

A1—the length from the center of the pad in the anchor assembly to the end face of the anchor.

When threading, the prestressed steel strand 2 should be adjusted in place according to the layout spacing, and it should be tightly wound on the surface of the prestressed steel cylinder concrete pipe body 1 to be reinforced, and the anchoring end is locked. After each threading groove is threaded, it needs to be backfilled with self-compacting concrete or special solidified soil. The outer edge of the backfill should be about 100mm higher than the foundation surface to prevent the pipe body from rolling.

5) Prestress tension and locking;

Multiple areas are divided along the length of the prestressed steel cylinder concrete pipe body 1, and the sequence of prestressed tension locking is firstly selected for the middle area, followed by the two end areas, and then completed symmetrically for the remaining areas. The prestress is stretched in stages to 20%, 25%, 50%, 75%, and 100% of the design tensile stress value, and over-tensioned to 115% of the design tensile stress value. , to check whether the stroke displacement of the anchorage at the tension end meets the requirements of the theoretical elongation, and the error between the stroke displacement of the anchorage at the tension end and the theoretical elongation should not be greater than ±6% according to the specifications.

6) Anti-corrosion at the tensioned anchorage end;

After all prestressed steel strands are tensioned and locked, in order to ensure the durability of the tensioned anchorage end, it is necessary to paint 3mm to 5mm of anti-corrosion material on the surface of the tensioned anchorage end in the prestressed reinforcement system for sealing treatment. Quality, each brushing should not exceed 1.0mm, and the next layer should be painted after the anti-corrosion material is dry, which needs to be completed several times.

7) Concrete surface protection, pipeline earthwork backfilling.

C15 concrete with a thickness of 100mm is used to protect the prestressed steel strand 2. Before backfilling the pipeline earthwork, the sundries in the trench must be removed and accumulated water must be removed. Backfilling shall not be carried out in the presence of accumulated water. Technical requirements such as backfill thickness and backfill shall be carried out according to the original design.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements can be made without departing from the technical principle of the present invention. and modifications, these improvements and modifications should also be considered as the protection scope of the present invention.

Claims (10)

1. A kind of external prestressing reinforcement system of prestressed steel cylinder concrete pipe, it is characterized in that: comprise: It includes: a plurality of prestressed steel strands arranged on the outer wall of the prestressed steel tube concrete pipe, and the first and last ends of the plurality of prestressed steel strands are fixed on the anchor plate through anchors. 2. The external prestressed reinforcement system of prestressed steel cylinder concrete pipe according to claim 1, wherein each described prestressed steel strand is fixed on an anchor plate by an anchorage, and the prestressed steel strand The wire is double-wound on the outer wall of the prestressed steel cylinder concrete pipe. 3. The external prestressed reinforcement system of prestressed steel cylinder concrete pipe according to claim 1, wherein two adjacent anchor plates are arranged in a staggered manner on the outer wall of the prestressed steel cylinder concrete pipe, and a plurality of anchors The plates are arranged in two rows, and the angles formed between the projection of the two adjacent anchor plates to the end face of the prestressed steel cylinder concrete pipe, the top position of the section and the center of the section are all 15°; An anti-corrosion sealing layer is provided on the outside of the tool and the anchor plate as a whole. 4. A prestressed steel cylinder concrete pipe external prestressed reinforcement system construction method, comprising the following steps: 1) Reinforcing pipeline excavation and support; 2) Preparation for construction, cleaning up the construction area, setting up workbenches and safety enclosures; 3) System layout, base surface treatment, anchor end installation; 4) Ring through the steel strand; 5) Prestress tension and locking; 6) Anti-corrosion at the tensioned anchorage end; 7) Concrete surface protection, pipeline earthwork backfilling. 5. The external prestressed construction method of prestressed steel tube concrete pipe according to claim 4, characterized in that: said step 1) specific steps are: earthwork excavation around the reinforcement pipe, when there are other pipelines around the reinforcement pipe , according to the relative position of the reinforced pipe and the adjacent pipeline, determine the excavation safety distance, and monitor the deformation of the pipe side soil; when the safety distance cannot be determined, use Larsen steel sheet piles to support and isolate the adjacent pipeline to ensure that Lateral slippage occurs, and the deformation of the soil on the side of the pipeline is monitored at the same time. 6. The external prestressing construction method of prestressed steel cylinder concrete pipe according to claim 4, characterized in that: said step 3) The specific steps are: determine the installation position of the prestressing system by measuring and setting out the line, when the prestressing steel cylinder The surface damage of the concrete pipe body is repaired and leveled with epoxy mortar; the anchor plates of the prestressed steel strands are arranged crosswise on the upper part of the prestressed steel cylinder concrete pipe body. 7. The external prestressing construction method of prestressed steel cylinder concrete pipe according to claim 4, characterized in that: said step 4) The specific steps are: before looping through the steel strands, the prestressed steel cylinder concrete pipe needs to be The bottom of the pipe body is excavated with a cable groove perpendicular to its axis to pass through the steel strand. The threading groove is divided into three parts along the length of the pipe. The principle of excavation is the two ends first and then the middle. During the excavation, manual excavation is mainly used to minimize disturbance to the soil foundation at the bottom of the pipe. When threading, the steel strands should be adjusted in place according to the layout spacing, and should be tightly wound on the surface of the prestressed steel cylinder concrete pipe to be reinforced, and the anchorage end should be locked. After each threading groove is threaded, it needs to be backfilled with self-compacting concrete or special solidified soil. 8. The external prestressing construction method of prestressed steel cylinder concrete pipe according to claim 4, characterized in that: said step 5) The specific steps are: divide a plurality of regions along the length of prestressed steel cylinder concrete pipe body, prestress The tensioning and locking sequence is to select the middle area first, then the two end areas, and then the remaining areas are symmetrically completed. 9. The external prestressing construction method of prestressed steel tube concrete pipe according to claim 4, characterized in that: said step 6) The specific steps are: after all prestressed steel strands are stretched and locked, the prestressed reinforcement system The surface of the anchoring end of the tension is painted with 3mm to 5mm thick anti-corrosion material for sealing treatment, and the anti-corrosion material is polyurea. 10. The external prestressed construction method of prestressed steel cylinder concrete pipe according to claim 4, characterized in that: said step 7) adopts C15 concrete with a thickness of 100mm to protect the prestressed steel strand; It is necessary to remove the sundries in the trench and remove the accumulated water, and it is not allowed to backfill in the case of accumulated water. Technical requirements such as backfill thickness and backfill shall be carried out according to the original design.