CN111997058B

CN111997058B - Construction method for preventing pile top concrete from chiseling and over-grouting

Info

Publication number: CN111997058B
Application number: CN202010769666.9A
Authority: CN
Inventors: 徐晨旭; 张卫东; 吴昊; 李晓倩
Original assignee: Sinohydro Bureau 11 Co Ltd; PowerChina 11th Bureau Engineering Co Ltd
Current assignee: Sinohydro Bureau 11 Co Ltd; PowerChina 11th Bureau Engineering Co Ltd
Priority date: 2020-08-04
Filing date: 2020-08-04
Publication date: 2021-11-23
Anticipated expiration: 2040-08-04
Also published as: CN111997058A

Abstract

The invention belongs to the field of engineering construction, in particular to a construction method for pile top concrete free from chiseling and overfill prevention for pile foundation engineering. The invention optimizes the pouring process of the cast-in-place concrete pile, reduces the amount of concrete pouring, and avoids the occurrence of the pile head chisel process in the later stage. Increase the density of the pile top concrete to form pile top concrete that can meet the design requirements of the pile top elevation and design strength, without over-filling concrete. On the premise that the pile top concrete meets the design strength, the construction method can reduce labor and mechanical input, reduce the consumption of concrete, reduce the construction period, and reduce the pollution to the environment, and has certain popularization and application value.

Description

Construction method for preventing pile top concrete from chiseling and over-grouting

Technical Field

The invention belongs to the field of engineering construction, and particularly relates to a construction method for pile top concrete chiseling-free and over-irrigation-prevention of pile foundation engineering.

Background

In order to ensure the concrete strength of the pile top in the concrete pile foundation engineering, the concrete pouring surface is usually specified to be higher than the designed elevation of the pile top by 0.5-1m in the construction, and the concrete of the over-poured part of the pile top is chiseled after the concrete strength of the pile body reaches the design requirement.

The prior method for removing pile top super-poured concrete comprises the following steps: manual chiseling method, mechanical cutting method, physical separation method, chemical spalling method and the like. The common construction method is that the pile top concrete is chiseled by a manual air blowing pick, in the process of chiseling the pile top concrete, because part of the main reinforcement of the reinforcement cage extends into the concrete at the part beyond the pouring of the pile top, the construction difficulty is increased, in order to separate the reinforcement from the concrete to be chiseled, and in some new processes, the main reinforcement of the reinforcement cage is separated from the concrete by adopting a partition plate method or a reinforcement sleeve method before the concrete is poured.

According to the construction idea of early concrete super-irrigation and later-stage concrete chiseling super-irrigation, the chiseling work of the pile top super-irrigation is an important construction process, and mechanical equipment and constructors need to be reasonably arranged.

For the construction of chiseling the concrete on the pile top, the prior construction method has the following problems:

(1) the construction efficiency is low: taking a small foundation pit with 50 piles as an example, pile heads are manually broken for 2-3 piles per day, and pile heads are mechanically broken for 5-8 piles per machine team. If 3 people are selected to perform manual chiseling at the same time, all chiseling needs 6-8 days; 6.25-10 shifts are needed for mechanical removal.

(2) The construction cost is high: in order to reduce the construction period of pile head chiseling and provide a working surface for subsequent work, the investment of personnel and mechanical equipment needs to be increased, and the management cost is relatively increased. The super-poured concrete also increases the construction cost, and the cost of the concrete with the pile diameter of 1m is about 300 yuan for the super-poured concrete with the diameter of 1 m.

(3) There is a security risk: pile top concrete chiseling construction belongs to high strength construction operation, and the work progress needs man-machine cooperation, the concrete fragment of chiseling can splash all around, and the safety risk in the construction has been increased to complicated environment.

(4) The environmental protection problem exists: dust, cement paste and noise are generated in the pile top concrete chiseling construction, and dust prevention and noise reduction measures need to be made in the construction process.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a construction method for preventing pile top concrete from chiseling and over-irrigation.

In order to achieve the purpose, the invention adopts the following technical scheme: a construction method for preventing pile top concrete from chiseling and over-filling comprises the following steps:

(1) the installation preparation work of the cast-in-place bored concrete pile top concrete strength hoisting equipment: sealing the pressure sensing piece and the connecting circuit, wherein the pressure sensing piece is adhered to the end head of the vibrating rod, the connecting circuit is fixed along the vibrating rod, and the end part of the slurry pump is 1-1.3 m higher than the end part of the vibrating rod;

(2) scale position preparation work: calculating the difference between the elevation delta h2 of the designed pile top of the concrete cast-in-place pile and the actual elevation delta h1 of the ground to obtain the depth of the empty concrete cast-in-place pile, ensuring that the lower end part of the vibrating rod is 1 meter lower than the designed elevation delta h2 of the pile top by controlling the lowering length of a rope with length scales, and pouring concrete to the elevation delta h2 of the designed pile top without over-pouring concrete;

(3) the equipment is in place: after pile hole excavation is finished and hole inspection is passed, installing a blanking guide pipe, fixing the lantern ring on the steel wire rope along the direction of the guide pipe, and putting the lantern ring to the scale position calculated in the step (2);

(4) pouring concrete: installing a hopper and pouring concrete;

(5) pumping and discharging sediments: along with the elevation delta h2 of the pouring top surface of the concrete, when sediment at the bottom contacts a pressure sensing piece adhered to the end part of the vibrating rod, the display reading of the pressure sensing piece has a mutation phenomenon, and at the moment, a mud pump is started to pump upwelling sediment out of the hole;

(6) concrete vibrating: when the display reading of the pressure sensing piece is changed suddenly again, the concrete is shown to be in contact with the pressure sensing piece, the vibrating rod is started, and sediment on the upper portion is vibrated during vibrating to be beneficial to pumping and discharging of the mud pump;

(7) and (4) observation: when the display reading of the pressure sensing piece does not change any more;

(8) lifting equipment: closing a slurry pump, keeping the vibrating rod to continue vibrating, and slowly pulling out the cast-in-place bored concrete pile top concrete strength lifting equipment;

(9) ending work: cleaning the vibrating rod, checking whether the pressure sensing sheet is damaged or not, and timely replacing the vibrating rod if the pressure sensing sheet cannot be used again;

(10) and (3) post-processing: after the concrete cast-in-place pile reaches the design strength, the pile head part of the concrete cast-in-place pile is only required to be chiseled and cleaned up, and then the subsequent construction can be carried out.

This pile bolck concrete intensity lifting means is annotated in preferred watering includes the stick that vibrates, pressure sensing piece, slush pump and rope, vibrates the fixed pressure sensing dish that sets up in stick bottom that vibrates, and the rope sets up in stick one side that vibrates, and the rope passes through the staple bolt and vibrates stick and slush pump looks fixed connection, and the slush pump sets up in stick one side that vibrates.

The side wall of the upper portion of the preferable blanking guide pipe is fixed with a fixing ring, the fixing ring comprises a first fixing ring and a second fixing ring, the first fixing ring is arranged on the upper portion of the second fixing ring, a steel wire rope is fixed between the first fixing ring and the second fixing ring, the steel wire rope is arranged between the first fixing ring and the second fixing ring in an overhead mode, the outer side of the rope is fixedly connected with a lantern ring, the steel wire rope penetrates through the lantern ring, and the lantern ring can slide up and down on the steel wire rope.

Preferably, the upper part of the blanking conduit is provided with a hopper which is communicated with the blanking conduit.

Compared with the prior art, the invention has the beneficial effects that: compared with the conventional cast-in-place pile pouring method, the construction method which adopts the pile top concrete and avoids chiseling and over-pouring has the advantages that:

(1) the labor, material and equipment investment is reduced, and the cost is saved. Taking a small foundation pit with the diameter of 50 piles being 1m as an example, the mixed concrete cost is about 1.5 ten thousand yuan (3.14 × 0.5 × 1 × 50 × 400), and the manpower cost is about 1.6 ten thousand yuan (3 × 800 × 7).

(2) The progress is accelerated, and the construction period is shortened. Taking a small foundation pit with 50 piles as an example, the construction period can be shortened by 5-8 days.

(3) Reducing the environmental pollution. The dust, cement paste and noise generated in the pile top concrete chiseling are reduced.

On the premise of meeting the requirement that the pile top concrete meets the design strength, the construction method can reduce the labor and mechanical investment, reduce the concrete consumption, shorten the construction period and reduce the pollution to the environment, and has certain popularization and application values.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the present invention.

Fig. 2 is a schematic diagram of the structure at a in fig. 1.

Detailed Description

The present invention will be described in further detail with reference to the following examples, which are provided only for illustrating the present invention and are not intended to limit the scope of the present invention.

Referring to fig. 1-2, a construction method for preventing pile top concrete from chiseling and over-irrigation includes the following steps:

(1) the installation preparation work of the cast-in-place bored concrete pile top concrete strength hoisting equipment: sealing the pressure sensing piece 2 and a connecting circuit, wherein the pressure sensing piece 2 is adhered to the end head of the vibrating rod 1, the connecting circuit is fixed along the vibrating rod 1, and the end part of the slurry pump 4 is 1-1.3 m higher than the end part of the vibrating rod 1;

(2) scale position preparation work: calculating the difference between the elevation delta h2 of the designed pile top of the concrete cast-in-place pile 11 and the actual elevation delta h1 of the ground to obtain the depth of the empty concrete cast-in-place pile, ensuring that the lower end part of the vibrating rod 1 is 1 meter lower than the designed elevation delta h2 of the pile top by controlling the lowering length of the rope 5 with length scales, and pouring concrete to the elevation delta h2 of the designed pile top without over-pouring concrete;

(3) the equipment is in place: after pile hole excavation is finished and hole inspection is passed, installing a blanking guide pipe 9, fixing a lantern ring 6 on a steel wire rope 7 along the direction of the guide pipe 9, and lowering to a scale position obtained through calculation in the step (2);

(4) pouring concrete: installing a hopper 10 and beginning to pour concrete;

(5) pumping and discharging sediments: along with the elevation delta h2 of the top surface of the concrete, when sediment at the bottom contacts the pressure sensing piece 2 adhered to the end part of the vibrating rod 1, the display reading of the pressure sensing piece 2 has a sudden change phenomenon, and at the moment, a mud pump 4 is started to pump and discharge upwelling sediment out of the hole;

(6) concrete vibrating: when the display reading of the pressure sensing piece 2 is changed suddenly again, the concrete is contacted with the pressure sensing piece 2, the vibrating rod 1 is started, and sediment on the upper part is vibrated to be beneficial to pumping and discharging of the mud pump 4;

(7) and (4) observation: when the display reading of the pressure sensing sheet 2 does not change any more, the vibrating compaction is indicated;

(8) lifting equipment: the slurry pump 4 is closed, the vibrating rod 1 is kept vibrating continuously, and the cast-in-place bored concrete pile top concrete strength lifting equipment is slowly pulled out;

(9) ending work: cleaning the vibrating rod 1, checking whether the pressure sensing sheet 2 is damaged or not, and replacing the vibrating rod in time if the vibrating rod cannot be used again;

(10) and (3) post-processing: after the concrete cast-in-place pile 11 reaches the design strength, the pile head part of the concrete cast-in-place pile 11 is only required to be chiseled and cleaned up, and the subsequent construction can be carried out.

Pouring pile top concrete intensity lifting equipment comprises a vibrating rod 1, a pressure sensing piece 2, a slurry pump 4 and a rope 5, wherein a pressure sensing disc 2 is fixedly arranged at the bottom of the vibrating rod 1, the rope 5 is arranged on one side of the vibrating rod 1, the rope 5 is fixedly connected with the vibrating rod 1 and the slurry pump 4 through a hoop 3, and the slurry pump 4 is arranged on one side of the vibrating rod 1; the vibrating rod 1 is an insertion type vibrating rod, the diameter of the vibrating rod is 50-80mm, and the vibrating frequency of the vibrating rod is an intermediate frequency type 83-133 HZ (5000-8000 times/min). The pressure sensing piece 2 is a film type flexible pressure sensing piece. The slurry pump 4 has low lift and a pipe diameter of 100 mm. The rope 5 is for taking length scale, tightly fixes the staple bolt for vibrating spear and slush pump pipe on rope 5, and the lantern ring 6 through fixing on rope 5 is followed wire rope 7 on the pipe and is transferred downwards, ensures that the pipeline of the in-process vibrating spear 1 of descending and slush pump 4 is near the stake center.

A fixing ring 8 is fixed on the side wall of the upper part of the blanking guide pipe 9, the fixing ring 8 comprises a first fixing ring 81 and a second fixing ring 82, the first fixing ring 81 is arranged on the upper part of the second fixing ring 82, a steel wire rope 7 is fixed between the first fixing ring 81 and the second fixing ring 82, the steel wire rope 7 is arranged between the first fixing ring 81 and the second fixing ring 82 in an overhead mode, the outer side of the rope 5 is fixedly connected with a lantern ring 6, the steel wire rope 7 penetrates through the lantern ring 6, and the lantern ring 6 can slide up and down on the steel wire rope 7;

the upper part of the blanking conduit 9 is provided with a hopper 10, and the hopper 10 is communicated with the blanking conduit 9.

The invention achieves the following effects:

(1) the cast-in-place concrete pile casting process is optimized, the concrete casting amount is reduced, and the later pile head chiseling procedure is avoided: in the pouring process of the cast-in-place pile, upwelling sediments are removed by utilizing cast-in-place pile top concrete strength lifting equipment, the compactness of the pile top concrete is increased, the pile top concrete which can meet the pile top elevation and the design strength of the design requirement is formed, and super-pouring concrete is not needed.

(2) The concrete consumption is saved: and by controlling the concrete pouring elevation, the super-pouring of concrete is avoided, the using amount of concrete is reduced, and the concept of green and environment-friendly construction is met.

(3) Shortening the construction period: due to the fact that pile head chiseling construction is omitted, subsequent construction is advanced, and the whole construction period is shortened.

(4) The quality of the concrete is ensured: the strength of the concrete pile head part is ensured by vibrating the vibrating rod in the cast-in-place bored concrete pile top concrete strength lifting equipment.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

Claims

1. a construction method of pile top concrete exempt from chiseling, preventing overfilling, is characterized in that, comprises the steps:

(1) Installation preparation of the concrete strength lifting equipment on the top of the cast-in-place pile: seal the pressure sensor sheet and the connecting line, paste the pressure sensor sheet on the end of the vibrating rod, and fix the connecting line along the vibrating rod. The end of the pump is 1-1.3 meters higher than the end of the vibrator;

(2) Preparatory work for the scale position: Calculate the difference between the design elevation Δh2 of the top of the concrete cast-in-place pile and the actual ground elevation Δh1 to obtain the depth of the empty concrete cast-in-place pile. The lower end of the tamping rod is 1 meter lower than the design elevation Δh2 of the pile top, and the concrete is poured to the design elevation Δh2 of the pile top without over-pouring concrete;

(3) The equipment is in place: after the excavation of the pile hole is completed and the hole inspection is completed, the blanking guide tube is installed, and the collar is fixed on the wire rope along the direction of the guide tube, and lowered to the scale position calculated by step (2);

(4) Concrete pouring: install the hopper and start pouring concrete;

(5) Sediment extraction: As the elevation of the top surface of the concrete pouring rises, when the bottom sediment contacts the pressure sensor sheet attached to the end of the vibrator, the display reading of the pressure sensor sheet will change abruptly. Turn on the mud pump to pump the upwelling sediment out of the hole;

(6) Vibration of concrete: when the displayed reading of the pressure sensor sheet suddenly changes again, it means that the concrete has contacted the pressure sensor sheet. At this time, the vibrating rod is turned on, and the upper part of the slag is vibrated during the vibration, which is helpful for the pumping of the mud pump. Row;

(7) Observation: when the displayed reading of the pressure sensor sheet no longer changes in detail;

(8) Lifting equipment: turn off the mud pump, keep the vibrating rod vibrating continuously, and slowly pull out the concrete strength lifting equipment on the top of the cast-in-place pile;

(9) Finishing work: clean the vibrating rod, check whether the pressure sensor is damaged, and replace it in time if it cannot be used again;

(10) Post-processing: After the concrete cast-in-place pile reaches the design strength, it is only necessary to clean up the pile head of the concrete cast-in-place pile, and then the subsequent construction can be started;

The equipment for improving the concrete strength of the cast-in-place pile top includes a vibrating rod, a pressure sensing piece, a mud pump and a rope. The pressure sensing piece is fixed at the bottom of the vibrating rod, the rope is set on one side of the vibrating rod, and the rope passes through the hoop It is fixedly connected with the vibrating rod and the mud pump, and the mud pump is arranged on one side of the vibrating rod;

A fixing ring is fixed on the upper side wall of the feeding guide. The fixing ring includes a fixing ring 1 and a fixing ring 2. The fixing ring 1 is arranged on the upper part of the fixing ring 2. A steel wire rope is fixed between the fixing ring 1 and the fixing ring 2. Between the first ring and the second fixed ring, the outer side of the rope is fixedly connected with the collar, the wire rope passes through the collar, and the collar can slide up and down on the wire rope;

A hopper is arranged on the upper part of the feeding duct, and the hopper is communicated with the feeding duct.