CN113957903A

CN113957903A - Secant pile structure with reinforcing function and construction method thereof

Info

Publication number: CN113957903A
Application number: CN202111247306.3A
Authority: CN
Inventors: 邱太岗; 付成; 王洪新
Original assignee: MCC Tiangong Group Corp Ltd
Current assignee: MCC Tiangong Group Corp Ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-01-21

Abstract

The invention provides an occlusive pile structure with a reinforcing function and a construction method thereof, wherein the occlusive pile structure comprises the following components: the first occlusive piles and the second occlusive piles are alternatively occluded and connected to form the occlusive piles; a crown beam is arranged at the upper part of the secant pile, a reinforcement cage stirrup is annularly arranged inside the first secant pile, and a reinforcement cage longitudinal reinforcement is arranged in a direction vertical to the reinforcement cage stirrup; and a grouting pipe is also longitudinally arranged in the first occlusive pile and used for grouting and leakage repairing in the occlusive pile. The invention has the advantages of simple structure, scientific and reasonable stress, convenient construction, low construction cost, no increase of construction period and safe and reliable construction quality. Through the even muscle mode of cloth of local, the interval of the vertical atress muscle of adjustment steel reinforcement cage makes the secant pile arrangement of reinforcement more reasonable, accords with the atress characteristics more, solves because of secant pile design reason, construction process or misoperation, the secant pile interlock width that leads to is not enough to cause foundation ditch seepage difficult problem.

Description

Secant pile structure with reinforcing function and construction method thereof

Technical Field

The invention belongs to the field of constructional engineering, and particularly relates to an occlusive pile structure with a reinforcing function and a construction method thereof.

Background

Along with the implementation of the national urbanization development strategy, urban land is more and more tense, and along with the continuous enhancement of the development strength of the underground space, the deep foundation pit support provides a safe and reliable construction environment for the development of the underground space. In some urban underground areas, pebbles and construction wastes exist, most of the urban underground areas adopt underground continuous walls or secant piles, and due to improper construction process, design or operation of the secant piles, insufficient meshing width of pile bodies is easily caused, leakage of a foundation pit support structure is caused, and construction inconvenience and even great potential safety hazards are brought to construction. At present, how many projects adopt a method of drilling holes outside a pit, grouting and plugging to remedy when finding hidden dangers, and the method is a post emergency measure and brings numerous adverse effects to underground space construction.

Disclosure of Invention

The invention aims to provide an occlusive pile structure with a reinforcing function and a construction method thereof, which are mainly used for the construction of the occlusive pile of the complex pebble (gravel) underground water rich stratum.

In order to solve the technical problems, the invention adopts the technical scheme that: a bite pile structure with a reinforcing function, comprising: the first occlusive piles and the second occlusive piles are alternatively occluded and connected to form the occlusive piles;

a crown beam is arranged at the upper part of the secant pile, a reinforcement cage stirrup is annularly arranged inside the first secant pile, and a reinforcement cage longitudinal reinforcement is arranged in a direction vertical to the reinforcement cage stirrup;

and a grouting pipe is also longitudinally arranged in the first occlusive pile and used for grouting and leakage repairing in the occlusive pile.

Furthermore, a plurality of groups of longitudinal steel bars of the steel reinforcement cage are arranged on one side, close to the inside of the foundation pit, of the first occlusive pile.

Furthermore, a plurality of groups of longitudinal steel bars of the steel reinforcement cage are arranged on one side, close to the outside of the foundation pit, of the first occlusive pile.

Furthermore, the setting area of one side of the longitudinal steel bars of the steel reinforcement cage close to the inside of the foundation pit is larger than the setting area of one side of the longitudinal steel bars outside the foundation pit.

Furthermore, the first occlusive pile is not provided with a constructional steel bar longitudinally arranged at the longitudinal steel bar of the steel reinforcement cage.

Further, the grouting pipe is arranged at the junction of the first occlusive pile and the second occlusive pile.

Further, the grouting pipe is arranged on the construction steel bar at the junction of the first occlusive pile and the second occlusive pile;

at least one grouting pipe is arranged.

Further, the construction steel bars and the steel reinforcement cage longitudinal steel bars extend into the crown beam;

the grouting pipe extends out of the upper part of the crown beam.

In order to achieve the above object, the present invention further provides a construction method of an occlusive pile structure with a reinforcement function, comprising the steps of:

and (3) guide wall construction: after the field is leveled and the measurement and setting-out are finished, the work of binding the reinforcing steel bars of the guide wall, installing the template and pouring concrete into the guide wall is carried out, and a positioning hole of the secant pile is reserved on the guide wall;

rotary drilling: adopting a rotary drilling mud retaining wall or full casing pipe retaining wall process to form holes, constructing the first secant pile and the second secant pile by a two-step hole jumping process, and cutting the first secant pile to form holes before concrete of the adjacent second secant pile is initially set;

manufacturing a steel reinforcement cage: the reinforcement cage comprises reinforcement cage stirrups arranged circumferentially along the inner part of the first occlusive pile and reinforcement cage longitudinal reinforcements arranged vertically to the reinforcement cage stirrups, the reinforcement cage is processed in a local uniform reinforcement distribution mode, the grouting pipe is arranged at the joint of the first occlusive pile and the second occlusive pile, and the upper end of the pipe orifice of the grouting pipe is temporarily blocked and protected;

hoisting a steel reinforcement cage: the grouting pipe is integrally hoisted along with the reinforcement cage, the reinforcement cage is hoisted into the positioning hole and is installed and fixed, secondary hole cleaning is carried out, and pile bottom sediment is reduced;

concrete pouring: pouring the second secant pile, cutting the first secant pile into a hole before initial setting of concrete adjacent to the second secant pile, and pouring the first secant pile after the second secant pile delays for a certain time;

injecting water into the pipe to open the plug: performing water injection and plugging opening within 5-7 days after the second occlusive pile is poured;

and (3) construction of a supporting structure: performing completeness inspection and quality inspection on the occlusive pile, performing construction on the crown beam, connecting the grouting pipe to be high, enabling the top of the grouting pipe to be higher than the upper surface of the crown beam, and lengthening the grouting pipe to finish the upper end sealing by adding a protective cap;

carrying out layered excavation on the foundation pit: the foundation pit excavation condition acceptance meets the standard, the foundation pit layered excavation is carried out, and the water level and the deformation condition of the foundation pit are observed in the process;

grouting reinforcement: and (3) discovering that the water level outside the foundation pit is abnormal in the excavation process, stopping excavating and troubleshooting hidden dangers, and grouting and plugging the water leakage part through the grouting pipe.

Further, in the guide wall construction step: the diameter D of the positioning hole of the guide wall is 30-50 mm larger than the diameter D of the secant pile, and the strength grade of concrete is not lower than C20;

the concrete pouring step comprises the following steps: the second occlusive pile is cast by adopting ultra-retarding concrete, the first occlusive pile is cast by adopting common concrete, and the retarding time of the ultra-retarding concrete is not less than 60 h;

the construction step of the supporting structure comprises the following steps: the top of the grouting pipe is higher than the upper surface of the crown beam by at least 100 mm.

Due to the adoption of the technical scheme, the method has the following beneficial effects:

the secant pile has the advantages of simple structural design, scientific and reasonable stress, convenient construction, simple process, low construction cost, no increase of construction period and safe and reliable construction quality, and is used for construction of the secant pile of the complex pebble (gravel) underground water rich stratum.

Through the even muscle mode of cloth of local, the interval of the vertical atress muscle of adjustment steel reinforcement cage makes the secant pile arrangement of reinforcement more reasonable, accords with the atress characteristics more, solves because of secant pile design reason, construction process or misoperation, the secant pile interlock width that leads to is not enough to cause foundation ditch seepage difficult problem.

The grouting pipe is used for replacing a structural steel bar, so that the structural requirement can be met, the grouting effect can be met, and the material consumption is not increased.

Drawings

FIG. 1 is a plan view of a secant pile construction guide wall according to one embodiment of the present invention;

FIG. 2 is a cross-sectional view of a secant pile construction guide wall according to an embodiment of the present invention;

FIG. 3 is a plan view of a bite pile reinforcement bar according to one embodiment of the present invention;

fig. 4 is an elevational view of a bite pile reinforcement according to one embodiment of the present invention.

In the figure:

1. concrete guide wall 2, guide wall reinforcing steel bar 3 and secant pile

3-1 parts of meat pile, 3-2 parts of vegetable pile and 4 parts of longitudinal steel bar of reinforcement cage

5. Reinforcement cage stirrup 6, grouting pipe 7 and concrete crown beam

Detailed Description

The invention is further illustrated by the following examples and figures:

in the construction process of the secant pile of the foundation pit support structure, because the internal and external sides of the pit of the secant pile body are stressed differently in the construction stage of the foundation pit, most of the internal part of the pit is a tension area, and most of the internal part of the pit is a compression area. And adjusting the steel cage steel bar spacing according to different stress characteristics. The reinforcing bars of the tension area are more than those of the compression area, the reinforcing bars of the areas outside the tension area and the compression area are properly reduced, the structural requirements are met, the grouting pipe is used for replacing longitudinal structural reinforcing bars at the outer junction of the occlusion pit of the meat and vegetable pile, the leakage part is found in the excavation process of the foundation pit, grouting reinforcement is carried out through the grouting pipe, and the effect of preventing leakage is achieved.

In one embodiment of the present invention, as shown in fig. 3 to 4, a bite pile structure having a reinforcing function, comprises: the pile comprises a first occlusive pile and a second occlusive pile, wherein a plurality of first occlusive piles and a plurality of second occlusive piles are alternatively occluded to form an occlusive pile 3; wherein 3 upper portions of secant pile still are provided with concrete crown beam 7, secant pile 3 and concrete crown beam 7 are the piece of pouring, the inside hoop ligature of first secant pile has steel reinforcement cage stirrup 5, vertical steel reinforcement cage stirrup 5's vertical steel reinforcement cage longitudinal reinforcement 4 that is provided with, steel reinforcement cage stirrup 5 and steel reinforcement cage longitudinal reinforcement 4 constitute secant pile 3's steel reinforcement cage jointly, first secant pile inside still vertically is provided with slip casting pipe 6, when taking place the seepage, can carry out the slip casting through slip casting pipe 6, reach the effect that prevents the seepage.

In the embodiment, the first snap pile is defined as a meat pile 3-1, and the second snap pile is defined as a vegetable pile 3-2.

As shown in fig. 3, a plurality of sets of longitudinal steel reinforcement cage reinforcements 4 are arranged on one side of the meat-meat pile 3-1 close to the inside of the foundation pit, a plurality of sets of longitudinal steel reinforcement cage reinforcements 4 are arranged on one side of the meat-meat pile 3-1 close to the outside of the foundation pit, and the setting area of one side of the longitudinal steel reinforcement cage reinforcements 4 close to the inside of the foundation pit is larger than that of one side of the longitudinal steel reinforcement cage reinforcements close to the outside of the foundation pit. The meat pile 3-1 is not provided with a steel reinforcement cage longitudinal steel bar 4, and a structural steel bar is longitudinally arranged. The grout pipe 6, the construction steel bars and the longitudinal steel bars 4 of the reinforcement cage extend into the concrete crown beam 7, and the grout pipe 6 extends out of the concrete crown beam 7.

In the embodiment, because the pile body of the pile is stressed differently on the inner side and the outer side of the pit in the foundation pit construction stage, most of the inside of the pit is a tension area, and most of the inside of the pit is a compression area. Therefore, the spacing of the reinforcement of the occlusive pile is adjusted according to different stress characteristics. 120 within range that is close to one side in the foundation ditch evenly is provided with the longitudinal reinforcement 4 of steel reinforcement cage of multiunit, 60 within ranges that is close to one side outside the foundation ditch evenly is provided with the longitudinal reinforcement 4 of steel reinforcement cage of multiunit, the longitudinal reinforcement 4 of steel reinforcement cage is calculated according to the atress and is arranged, evenly be provided with the structure reinforcing bar in the region that does not be provided with the longitudinal reinforcement 4 of steel reinforcement cage in meat stake 3-1, compare in the preceding evenly arranged reinforcing bar in the interlock stake, the arrangement of interlock stake arrangement of reinforcement has been changed to this embodiment, can reach better atress effect, the structure of interlock stake 3 is more firm.

The structure reinforcing steel bars are mainly arranged at the junction of the outer sides of the meat-vegetable pile occlusion pits, the positions, close to the inside of the foundation pit and the positions, outside the foundation pit, of the meat-vegetable piles 3-1 are not main stress positions, therefore, the structure reinforcing steel bars are uniformly distributed, the structure reinforcing steel bars are not stress reinforcing steel bars, in the embodiment, the distance between every two adjacent structure reinforcing steel bars is not more than 250mm, the structure reinforcing steel bars are arranged on the left side and the right side, and the size of each structure reinforcing steel bar is larger than 12 mm.

As shown in fig. 3 and 4, the grouting pipe 6 is arranged on the constructional steel bars at the outer junction of the meat-vegetable pile occlusion pit, at least one grouting pipe 6 is arranged along the constructional steel bars, if a leakage part is found in the excavation process of the foundation pit, grouting reinforcement is performed through the grouting pipe 6 for sealing, and the effect of preventing leakage is achieved. It is conceivable that the grouting pipe 6 may be used instead of the longitudinal structural steel bars, and may also serve as a support while having little influence on the manufacturing cost.

In the embodiment, two grouting pipes 6 are arranged, namely, one grouting pipe 6 is arranged at the junction of each meat pile 3-1 and two adjacent vegetable piles 3-2, so that the grouting, leakage repairing and covering areas are wider; and the slip casting pipe 6 is full section slip casting pipe in this embodiment, evenly sets up the hole that can supply concrete thick liquid to flow out on the slip casting pipe 6 promptly, is convenient for follow-up in-process of subsiding, carries out the slip casting to the seepage position. In the construction process, the grouting pipes 6 are integrally arranged along with the reinforcement cages of the meat-bearing piles 3-1 and integrally placed in the reserved apertures in the construction process to pour the occlusive piles, and the grouting pipes 6 are arranged at the junctions of each meat-bearing pile 3-1 and two adjacent vegetable piles 3-2, so that the influence of dismantling or damage of the grouting pipes 6 when the grouting pipes are arranged on the vegetable piles 3-2 and the subsequent drilling construction of the meat-bearing piles 3-1 can be avoided.

As shown in fig. 4, in this embodiment, the crown beam 7 is a member that is actually stressed in the future, and in the process of constructing the crown beam 7, the grouting pipe 6 extends out of the top of the crown beam 7, and meanwhile, the longitudinal steel bars 4 of the steel reinforcement cage are reserved to have a length that is deep into the crown beam 7 when constructing the occlusive pile 3, so that the subsequent construction of the crown beam 7 is facilitated, and the occlusive pile 3 is conducted to the crown beam 7 after being stressed, thereby meeting the stress requirement of the whole occlusive pile and the crown beam, and further prolonging the service life of the whole occlusive pile and the crown beam.

Meanwhile, before the construction of the occlusive pile 3, the concrete guide wall 1 needs to be poured, the arrangement of reinforcing steel bars is carried out firstly, the position of the occlusive pile 3 is reserved during pouring, drilling operation is carried out, the steel reinforcement cage and the grouting pipe 6 of the manufactured occlusive pile 3 are directly placed in the drilled hole, and after the occlusive pile 3 is poured, the concrete guide wall 1 is removed.

The working process of one embodiment of the invention is as follows:

and (3) construction of the concrete guide wall 1: after the site is leveled and the measurement and paying-off are finished, binding of guide wall reinforcing steel bars 2 is carried out, wherein the guide wall reinforcing steel bars 2 are arranged in a bidirectional mode, namely the guide wall reinforcing steel bars 2 are uniformly distributed longitudinally and transversely, and then formwork installation and concrete pouring are carried out;

the concrete guide wall is provided with positioning holes of the secant pile 3, the sizes of the positioning holes are shown in figure 2, the diameter D of each positioning hole is 30-50 mm larger than the diameter D of the secant pile 3, the thickness H1 of the guide wall is more than or equal to 300mm, the thickness H2 of the guide wall is 400-500 mm, the width B1 of the guide wall is more than or equal to 1000mm, the width B2 of the guide wall is more than or equal to 300mm, the construction strength of the concrete guide wall 1 is ensured, the strength grade of the concrete is not lower than C20, and large equipment cannot operate or stop nearby the concrete before the concrete reaches the designed strength; it is conceivable that the respective parameter values may be adjusted appropriately according to the size of the interlocking pile 3 to be constructed, the weight of large-scale equipment, the site construction environment, the condition of the foundation pit, and the like.

Rotary drilling: the hole forming is carried out by adopting a process of rotary drilling mud retaining wall or full casing retaining wall, the meat-vegetable pile of the secant pile is constructed by a two-step hole jumping process, and the meat-vegetable pile 3-1 is cut to form a hole before the concrete of the adjacent vegetable pile 3-2 is initially set.

Manufacturing a steel reinforcement cage: the manufacturing of the reinforcement cage adopts a local uniform reinforcement distribution mode to process the reinforcement cage, two full-section reinforcing grouting pipes 6 are arranged at the joint of meat and vegetable piles of the reinforcement cage 3-1, and temporary plugging protection is carried out at the upper ends of the pipe orifices of the grouting pipes 6.

Hoisting a steel reinforcement cage: the grouting pipe 6 is integrally hoisted along with the whole reinforcement cage, so that the orifice connection quality hidden danger of the positioning hole is avoided, the integral welding quality is higher, and the grouting pipe 6 is prevented from being welded independently, so that the position is inconvenient or the welding quality is not high. And the steel reinforcement cage is hung in the positioning hole and is firmly installed and fixed, and secondary hole cleaning is carried out, so that the pile bottom sediment meets the design requirement.

Concrete pouring: and 3-1 meat piles are cut into holes before the concrete of 3-2 adjacent vegetable piles is initially set, 3-2 vegetable piles are poured by adopting super-retarded concrete, and 3-1 meat piles are poured by adopting common concrete. Wherein the delayed coagulation time of the super delayed coagulation concrete is not less than 60h, the slump during the pouring of dry holes of the super delayed coagulation concrete is more than 140mm, and the slump during the underwater pouring is not more than 180 mm. And arranging a sand pile before the initial pile, and adopting water stopping treatment at the joint of the sand pile.

Injecting water into the pipe to open the plug: injecting water within 5-7 days after the plain piles 3-2 are poured, ensuring that the grouting pipes 6 can be effectively opened, meeting the later grouting requirement, and as a replaceable scheme, injecting low-concentration slurry of non-solidified materials such as bentonite and the like to open plugs;

and (3) construction of a supporting structure: the occlusive pile 3 is subjected to completeness inspection, after the inspection quality meets the requirement, construction of the top beam 7 is carried out, the grouting pipe 6 is connected to be high, the top of the grouting pipe is made to be higher than the upper surface of the top beam 7 by at least 100mm, in the embodiment, the value is taken within the range of 150-200 mm, the requirement of connection with a grouting pump pipe is met, meanwhile, resource waste is avoided, and extension is completed to seal a protective cap.

grouting reinforcement: the water level outside the foundation pit is found to be abnormal in the excavation process, excavation is stopped, hidden dangers are eliminated, grouting plugging is carried out on the water leakage position through the grouting pipe 6, the water leakage position in the pit is temporarily closed under the condition of small water leakage, and back pressure soil plugging is backfilled in the foundation pit under the condition of large water leakage, so that the large loss of slurry is avoided.

This embodiment is through the arrangement of reinforcement mode and through the slip casting pipe of improving the secant pile, because the straightness that hangs down has some deviation, secret stone pillar to cause inclined to one side hole, interlock not in place, perhaps when forming the seepage, carries out the slip casting reinforcement through the slip casting pipe and seals, reaches the effect that prevents the seepage, is fit for the construction of complicated stratum environment and the abundant secant pile of groundwater.

The embodiments of the present invention have been described in detail, but the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims

1. A bite pile structure with a reinforcing function, comprising: the first occlusive piles and the second occlusive piles are alternatively occluded and connected to form the occlusive piles;

2. A bite pile structure with reinforcing function as claimed in claim 1, wherein: and a plurality of groups of longitudinal steel bars of the steel reinforcement cage are arranged on one side of the first occlusive pile close to the inside of the foundation pit.

3. A bite pile structure with a reinforcing function according to claim 2, wherein: and a plurality of groups of longitudinal steel bars of the steel reinforcement cage are arranged on one side of the first occlusive pile, which is close to the outside of the foundation pit.

4. A bite pile structure with reinforcing function as claimed in claim 3, wherein: the setting area of one side of the longitudinal steel bars of the steel reinforcement cage close to the foundation pit is larger than the setting area of one side of the longitudinal steel bars outside the foundation pit.

5. A bite pile structure with reinforcing function as claimed in claim 4, wherein: and the first occlusive pile is not provided with the constructional steel bars longitudinally arranged at the longitudinal steel bar position of the steel reinforcement cage.

6. A bite pile structure with reinforcing function as claimed in claim 5, wherein: the grouting pipe is arranged at the junction of the first occlusive pile and the second occlusive pile.

7. A bite pile structure with reinforcing function as claimed in claim 6, wherein: the grouting pipe is arranged on the construction steel bar at the junction of the first occlusive pile and the second occlusive pile;

at least one grouting pipe is arranged.

8. A bite pile structure with a reinforcing function as set forth in claim 7, wherein: the construction steel bars and the steel reinforcement cage longitudinal steel bars extend into the crown beam;

the grouting pipe extends out of the upper part of the crown beam.

9. A construction method using a bite pile structure with a reinforcing function according to claim 1, characterized by comprising the steps of:

10. A construction method of a bite pile structure with a reinforcing function according to claim 9, characterized in that:

the guide wall construction step comprises the following steps: the diameter D of the positioning hole of the guide wall is 30-50 mm larger than the diameter D of the secant pile, and the strength grade of concrete is not lower than C20;