CN212248221U

CN212248221U - Structure for limiting horizontal displacement of pile foundation in deformable rock formation

Info

Publication number: CN212248221U
Application number: CN202020919087.3U
Authority: CN
Inventors: 张生; 袁松; 王希宝
Original assignee: Sichuan Communication Surveying and Design Institute Co Ltd
Current assignee: Sichuan Communication Surveying and Design Institute Co Ltd
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2020-12-29
Anticipated expiration: 2030-05-27

Abstract

The utility model discloses a structure of restriction pile foundation horizontal displacement in deformable body stratum relates to pile foundation construction technical field, has solved the technical problem that construction measure among the prior art can't deal with the phyllite stratum and cause pile foundation horizontal displacement. The structure comprises an anti-deformation structure and a buffer structure, wherein the anti-deformation structure is an annular structure which is arranged at the periphery of the pile foundation and anchored into a non-deformation rock stratum, and the buffer structure is arranged between the pile foundation and the anti-deformation structure. The utility model discloses set up the anchor in the non-deformation body stratum of deformation within range of rock stratum and go into the annular anti-deformation structure in the non-deformation body stratum, set up buffer structure between pile foundation and annular anti-deformation structure, prevent the horizontal displacement that the deformation body stratum displacement directly caused the pile foundation through anti-deformation structure on the one hand, on the other hand cushions through buffer structure antagonism deformation structure's displacement to allow the deformation body stratum to warp in the certain limit, the effectual horizontal displacement who restricts the interior pile foundation of deformation body stratum.

Description

Structure for limiting horizontal displacement of pile foundation in deformable rock formation

Technical Field

The utility model relates to a pile foundation construction technical field particularly, indicates a structure of restriction pile foundation horizontal displacement in the deformation body stratum.

Background

In recent years, more and more mountain roads are planned and constructed. The planning and construction of mountain roads and the planning and construction of bridges and tunnels which cannot be opened in the construction of mountainous areas, particularly bridges with high seismic intensity, fault fracture zones and phyllite strata in southwest mountainous areas bring great difficulty to the construction of tunnels. Especially, the phyllite deformable body brings great hidden danger to the bridge structure safety.

Phyllite strata are soft in lithology and easy to argillize and soften when meeting water, so that large deformation can be caused, rock deformation can generate horizontal extrusion acting force on the pile foundation of the bridge, the pile foundation in the range of the deformed rock stratum can generate horizontal displacement, and the pile foundation and the supporting effect of the pile foundation on the bridge are greatly influenced. In the prior art, the foundation treatment is generally carried out on phyllite strata with small volume and shallow depth of burial by adopting a replacement filling mode, but the mode needs a large amount of excavation construction, so that the construction period is long, and the construction cost is high. Is not suitable for the situation of phyllite strata with large volume and deep burial depth. How to effectively treat phyllite strata has become a difficult problem in the engineering world, and although many colleges and construction units do relevant research, a unified and effective treatment method is not provided, because the rock stratum occurrence, the individual conditions of the deformation bodies and the specific strength of phyllite in different areas are different, the method cannot be concluded.

Therefore, it is an urgent technical problem to be solved by those skilled in the art to provide a pile foundation protection structure which is suitable for phyllite strata and can limit the horizontal displacement of a bridge pile foundation.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model discloses the first aspect provides a structure of restriction pile foundation horizontal displacement in the deformable body stratum to solve the technical problem that construction measures among the prior art can't deal with the phyllite stratum and cause pile foundation horizontal displacement.

In order to solve the technical problem, the utility model provides a following technical scheme:

the utility model provides a structure of restriction pile foundation horizontal displacement in deformable body stratum, includes anti-deformation structure and buffer structure, anti-deformation structure is for setting up the loop configuration in pile foundation periphery, the bottom of anti-deformation structure surpasss the bottom of deformable body stratum and in the anchor non-deformable body stratum, buffer structure sets up between pile foundation and anti-deformation structure, the anti-deformation structure resists the power that the deformable body stratum produced because of warping, the displacement that buffer structure buffering anti-deformation structure produced.

On the basis of the technical scheme, the structure for limiting the horizontal displacement of the pile foundation in the deformed body rock stratum can be further improved as follows.

Further, the anti-deformation structure comprises a first protective barrel and a second protective barrel which are anchored into the non-deformation rock stratum, and anti-deformation concrete used for forming the anti-deformation structure is arranged between the first protective barrel and the second protective barrel.

Further, the concrete grade of the deformation-resistant concrete is the same as that of the pile foundation.

Further, a third pile casing for pouring the pile foundation is arranged in the second pile casing, and the third pile casing is anchored into the non-deformation rock stratum.

Further, a sensor for monitoring horizontal displacement of the pile foundation is arranged on the outer side wall of the third pile casing.

Furthermore, coarse sand for forming a buffer structure is filled between the second protective cylinder and the third protective cylinder.

Further, the radius of the third pile casing is 18 cm larger than that of the pile foundation, the radius of the second pile casing is 20 cm larger than that of the third pile casing, and the radius of the first pile casing is 30 cm larger than that of the second pile casing.

Further, the depth of anchoring the deformation-resistant structure into the non-deformed body rock formation is more than 2 meters.

Compared with the prior art, the utility model, have following advantage:

the utility model provides a structure of restriction pile foundation horizontal displacement in deformable body rock stratum sets up the anchor in the deformable body rock stratum within range and goes into the intraformational annular anti-deformation structure of non-deformable body rock, and set up buffer structure between pile foundation and annular anti-deformation structure, prevent the horizontal displacement that the deformable body rock stratum displacement directly caused the pile foundation through anti-deformation structure on the one hand, on the other hand cushions through buffer structure counter deformation structure's displacement, thereby allow the deformable body rock stratum to warp in the certain limit, the effectual horizontal displacement who restricts the pile foundation in the deformable body rock stratum, can be applicable to the intraformational pile foundation protection of various deformable body rock, and the construction is simple, engineering cost is lower.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a cross-sectional view of the structure of the present invention for limiting horizontal displacement of a pile foundation in a deformed body formation;

fig. 2 is the top view of the structure of the utility model for limiting the horizontal displacement of the pile foundation in the deformed rock layer.

Reference numbers and corresponding reference designations in the drawings:

1. a first casing; 2. a second casing; 3. a third pile casing; 4. anti-deformation concrete; 5. coarse sand; 6. a sensor; 7. pile foundations; 8. a deformable body rock formation; 9. a non-deformable body formation.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the following examples and drawings, and the exemplary embodiments and descriptions thereof of the present invention are only used for explaining the present invention, and are not intended as limitations of the present invention.

Example 1

A structure for limiting horizontal displacement of a pile foundation in a deformed body rock stratum is shown in figures 1 and 2 and comprises a first pile casing 1, a second pile casing 2 and a third pile casing 3 which are arranged on the periphery of a pile foundation 7. The radius of the third pile casing 3 is larger than the radius 18 cm of the designed section of the pile foundation 7 (considering the influence of foundation construction errors), the radius of the second pile casing 2 is larger than the radius 20 cm of the third pile casing 3, and the radius of the first pile casing 1 is larger than the radius 30 cm of the second pile casing 2. The bottoms of the first casing 1, the second casing 2 and the third casing 3 all exceed the bottom of the deformable body rock formation 8 and are anchored into the non-deformable body rock formation 9.

As shown in fig. 1 and 2, the deformation-resistant concrete 4 is filled between the first casing 1 and the second casing 2, and preferably, the deformation-resistant concrete 4 has the same concrete grade as that of the pile foundation 7 and is underwater concrete. The deformation-resistant concrete 4 is selected from plain concrete or reinforced concrete according to the conditions of the non-deformation rock stratum 9. The deformation-resistant concrete 4 serves to resist the force generated by the deformation of the transformed body rock layer 8. Coarse sand 5 is filled between the second casing 2 and the third casing 3 for buffering the displacement of the deformed concrete 4.

As shown in fig. 1 and 2, a pile foundation 7 is cast in the third casing 3, and a sensor 6 for monitoring horizontal displacement of the pile foundation 7 is mounted on an outer side wall of the third casing 3. The sensor 6 adopts an FS-ZWY linear displacement sensor or a resistance strain gauge capable of monitoring the horizontal displacement of the pile foundation 7 to transmit the horizontal displacement of the pile foundation 7 in real time. The sensors 6 arranged on the outer side wall of the third pile casing 3 are generally distributed at the upper, middle and lower different positions of the third pile casing 3, the horizontal displacement values of the three different positions are respectively taken to monitor the horizontal displacement of the pile foundation 7, and the monitoring accuracy is ensured.

It should be noted that the thickness of the deformation-resistant concrete 4 between the first casing 1 and the second casing 2 and the thickness of the coarse sand 5 between the second casing 2 and the third casing 3 are appropriately adjusted according to the thickness of the deformation rock layer 8, and are not limited to 30 cm and 20 cm. The anchoring depth of the first casing 1, the second casing 2 and the third casing 3 into the non-deformable rock stratum 9 is adjusted according to the depth of the deformable rock stratum 8, and is generally required to be more than 2 meters. The thickness of the first casing 1, the second casing 2 and the third casing 3 is generally 12 mm, and is appropriately adjusted according to the depth of the deformable rock layer 8.

The utility model discloses set up the anti deformation concrete 4 protection architecture of annular of pile foundation 7 periphery in the within range of the deformation body stratum 8 to fill 5 buffer structure of coarse sand between pile foundation 7 and anti deformation concrete 4, because in the bottom anchor of anti deformation concrete 4 goes into non-deformation body stratum 9, make the bottom of anti deformation concrete 4 receive the restraint of non-deformation body stratum 9. When the deformation of the deformable rock stratum 8 generates force on the pile foundation 7, the deformation-resistant concrete 4 can resist the deformation force, and the horizontal displacement of the deformable rock stratum 8 on the pile foundation 7 is prevented. In addition, the deformation-resistant concrete 4 with the annular structure can also decompose the deformation force into the force acting in the deformable rock stratum 8, and the action of the force of the deformable rock stratum 8 is reduced. Meanwhile, the coarse sand 5 can buffer the displacement of the deformation-resistant concrete 4 due to the deformation force, thereby allowing the deformation body rock layer 8 to deform within a certain range. The sensor 6 arranged on the outer side wall of the third pile casing 3 enables the bridge to reflect the horizontal displacement of the pile foundation 7 in real time during operation and give an early warning in time, so that the serious consequences of bridge damage caused by untimely monitoring of the horizontal displacement of the pile foundation 7 are avoided.

The utility model discloses protect to the single pile basis respectively, need not the excavation of large tracts of land, trade and fill the construction, can effectually prevent the horizontal displacement of 8 interior pile foundations of deformable body terrane 7, be applicable to the pile foundation construction under the multiple geological conditions to the construction is simple, the operation of being convenient for, and engineering cost is lower, and the advantage is obvious, convenient to popularize and use.

Example 2

For better realization the utility model discloses, this embodiment still provides a construction method who restricts pile foundation horizontal displacement in the deformation body stratum on the basis of above-mentioned embodiment, particularly, including following step:

as shown in fig. 1 and 2, the actual situation such as the thickness and the range of the deformed rock layer 8 is first investigated in detail to ensure the accuracy of the geological situation. Calculating the section size of the pile foundation 7 according to the stress condition, the bearing capacity limit state and the normal use limit state of the bridge pile foundation 7, wherein if the bridge pile foundation is an end-bearing pile, the bottom of the pile foundation 7 must completely penetrate through a deformed body rock stratum 8; in the case of friction piles, the frictional force provided by the rock-soil within the range of the deformed body rock stratum 8 is not considered.

As shown in fig. 1 and 2, in the hole forming, the center of the cross section of the first casing 1 is overlapped with the center of the cross section of the pile foundation 7, and the first casing 1 is vertically driven into the ground by construction equipment so that the bottom of the first casing 1 exceeds the bottom of the deformed rock layer 8. And (3) drilling the rock stratum in the area of the first casing 1 to the bottom of the first casing 1 by adopting a drill bit matched with the first casing 1, and simultaneously adopting mud for wall protection.

After the drilling is finished, the third casing 3 is anchored into the non-deformable rock stratum 9 in the area of the first casing 1, so that the center of the section of the third casing 3 coincides with the center of the section of the pile foundation 7. The length of the third casing 3 is longer than that of the first casing 1, so that the third casing 3 is anchored into the non-deformable rock stratum 9 in advance in the early stage of drilling, and drilling of holes of the pile foundation 7 is facilitated. The size of the third casing 3 is based on the cross-sectional dimension of the pile foundation 7 design, allowing a slight enlargement to meet the relevant requirements of the pile foundation construction specifications.

And (3) replacing a drill bit matched with the third casing 3 to drill the rock stratum in the area of the third casing 3 to the bearing stratum of the pile foundation 7, and simultaneously adopting slurry to protect the wall to prevent hole collapse. After pore-forming, the holes of the pile foundation 7 are cleaned through positive and negative circulation of slurry, then a reinforcement cage of the pile foundation 7 is lowered, and concrete is poured to form the pile foundation 7.

After the pile foundation 7 is formed, a second pile casing 2 anchored into the non-deformable rock stratum 9 is installed between the first pile casing 1 and the third pile casing 3, so that the center of the section of the second pile casing 2 coincides with the center of the section of the pile foundation 7. Wherein, adopt the short steel bar welding to protect between a section of thick bamboo 1 and the second protects a section of thick bamboo 2 in order to protect a section of thick bamboo 2 to the second and fix a position. And pouring underwater concrete with the same grade as the concrete of the pile foundation 7 between the first pile casing 1 and the second pile casing 2 to form anti-deformation concrete 4, wherein the slurry between the first pile casing 1 and the second pile casing 2 is ejected out under the action of the gravity of the underwater concrete.

Finally, slurry between the second casing 2 and the third casing 3 is pumped out, and a sensor 6 for monitoring horizontal displacement of a pile foundation 7 is mounted on the outer side wall of the third casing 3. Wherein, the sensor 6 can be installed by adopting a construction mode of firstly pumping out slurry and then sticking the slurry on the outer wall of the third casing 3 through structural adhesive; the sensor 6 can also be installed by adopting a construction mode that the installation box is welded on the outer wall of the third casing 3 in advance and then the installation box is sealed by sealing glue. And then the coarse sand 5 is filled between the second pile casing 2 and the third pile casing 3 to form a buffer structure, so that the construction of a structure for limiting the horizontal displacement of the pile foundation in the deformed rock stratum is completed.

The utility model provides a construction method of restriction pile foundation horizontal displacement in deformable body stratum rock layer need not the excavation of large tracts of land, trades and fills out the construction, and the construction steps is compact, and the construction material, the construction equipment that adopt are conventional construction material, construction equipment, and the implementation of being convenient for, engineering cost is lower, and the advantage is obvious, convenient to popularize and use.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above description is only the embodiments of the present invention, and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The structure for limiting the horizontal displacement of the pile foundation in the deformable body rock stratum is characterized by comprising a deformation-resistant structure and a buffer structure, wherein the deformation-resistant structure is an annular structure arranged on the periphery of the pile foundation (7), the bottom of the deformation-resistant structure exceeds the bottom of the deformable body rock stratum (8) and is anchored into the non-deformable body rock stratum (9), the buffer structure is arranged between the pile foundation (7) and the deformation-resistant structure, the deformation-resistant structure resists the force generated by the deformation of the deformable body rock stratum (8), and the buffer structure buffers the displacement generated by the deformation-resistant structure.

2. A structure for limiting the horizontal displacement of pile foundations in a deformed body rock formation according to claim 1, characterized in that the deformation-resistant structure comprises a first casing (1) and a second casing (2) anchored in a non-deformed body rock formation (9), between which first casing (1) and second casing (2) there is arranged a deformation-resistant concrete (4) for forming a deformation-resistant structure.

3. A structure for limiting the horizontal displacement of pile foundations in a deformed body formation according to claim 2, characterized in that the concrete grade of the deformation-resistant concrete (4) is the same as the concrete grade of the pile foundation (7).

4. The structure for limiting the horizontal displacement of pile foundations in a deformable body formation according to claim 2, characterized in that a third casing (3) for casting the pile foundation (7) is arranged in the second casing (2), the third casing (3) being anchored in the non-deformable body formation (9).

5. A structure for limiting the horizontal displacement of pile foundations in a deformed body formation as claimed in claim 4, characterized in that the outer side wall of the third casing (3) is provided with a sensor (6) for monitoring the horizontal displacement of the pile foundation (7).

6. A structure for limiting the horizontal displacement of pile foundations in a deformed body formation according to claim 5, characterized in that the second casing (2) and the third casing (3) are filled with grit (5) for forming a buffer structure.

7. A structure for limiting the horizontal displacement of pile foundations in a deformed body formation according to claim 6, characterized in that the radius of the third casing (3) is 18 cm greater than the radius of the pile foundation (7), the radius of the second casing (2) is 20 cm greater than the radius of the third casing (3), and the radius of the first casing (1) is 30 cm greater than the radius of the second casing (2).

8. A structure in a deformable body formation to limit the horizontal displacement of pile foundations as claimed in any one of claims 1 to 7, characterized in that the anti-deformation structure is anchored into the non-deformable body formation (9) to a depth greater than 2 meters.