CN218757506U - Protection structure for sensitive building close to water-rich sandy soil foundation pit - Google Patents

Abstract

The utility model relates to a close on sensitive building protection architecture of rich water sand foundation ditch, be located between foundation ditch (1) and sensitive building (4), including division wall (2) and recharge well (3), recharge well (3) locate between division wall (2) and sensitive building (4). Compared with the prior art, the utility model discloses can reduce simultaneously in the stratum foundation ditch earthwork excavation and hole precipitation to closing on sensitive building influence.

Description

Protection structure for sensitive building close to water-rich sandy soil foundation pit

Technical Field

The utility model belongs to the technical field of foundation and foundation engineering construction technique and specifically relates to a close on sensitive building protection architecture of rich water sand foundation ditch.

Background

With the continuous promotion of the urbanization process, underground space resources are increasingly tense, the problem of traffic congestion is increasingly apparent, and the rapid development of the underground space resources becomes an effective way for solving the problem. The underground space development usually involves a foundation pit excavation project in a central area of a city, and unloading effect caused by excavation can change the initial stress and strain state of a stratum soil body, so that peripheral sensitive buildings are easily exposed to risks of overlarge settlement, inclination, even collapse and the like. In addition, when a foundation pit is constructed in a water-rich sandy stratum, special geological conditions such as high underground water level, large sand layer thickness, small cohesive force, strong permeability and the like need to be faced, the drying condition and the pit bottom stability of construction are ensured by inevitably carrying out in-pit drainage and pressure reduction and precipitation, the underground water level is obviously reduced outside the pit within the influence range of a funnel formed by precipitation, and a peripheral sensitive building is subjected to consolidation settlement due to the increase of effective stress of a soil body below the peripheral sensitive building, so that the differential settlement of the peripheral building is further increased.

At present, aiming at the protection problem of a sensitive building close to a water-rich sandy soil foundation pit, the adverse effect generated by foundation pit excavation is reduced by using a wider isolation pile technology in a soft soil area for reference, but the following defects still exist:

first, the spacer piles are typically arranged with a certain pile spacing, which results in insufficient integrity of the spacer piles; when the sand-soil separation pile is applied to a water-rich sandy stratum with small cohesive force, sand-soil particles easily penetrate through gaps among the piles of the separation pile to cause water and soil loss under the action of seepage force caused by precipitation in a pit, and the deformation and separation effect of the stratum is not ideal;

secondly, the problem that the underground water level of a sensitive building outside the pit obviously drops due to precipitation in the pit cannot be solved only by arranging the isolation piles, and the difference settlement of the soil body below the isolation piles is further increased due to the increase of effective stress, so that the safety of the building is endangered.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a close on sensitive building protection architecture of rich water sand foundation ditch in order to overcome the defect that above-mentioned prior art exists, can reduce simultaneously in the stratum foundation ditch earthwork excavation and the hole precipitation to closing on sensitive building influence.

The purpose of the utility model can be realized through the following technical scheme:

a sensitive building protection structure close to a water-rich sandy soil foundation pit is positioned between the foundation pit and a sensitive building and comprises a partition wall and a recharge well, wherein the recharge well is arranged between the partition wall and the sensitive building.

Furthermore, the number of the recharging wells is multiple.

Further, a plurality of recharging wells are arranged at intervals along a direction parallel to the partition wall.

Furthermore, the distance between the adjacent recharging wells is 4-8 m.

Furthermore, a plurality of recharging wells are evenly arranged at intervals.

Furthermore, the partition wall is a reinforced concrete wall.

Further, the recharging well is an incomplete well.

Further, the incomplete well adopts a bridge type filter pipe.

Furthermore, the bridge type strainer comprises a solid pipe, a filtering section and a settling pipe from top to bottom in sequence.

Further, the length of the filtering segment is not less than 10m.

Compared with the prior art, the utility model discloses have with following beneficial effect:

(1) The protection structure of the utility model comprehensively utilizes the advantages of the isolation wall and the recharge well, respectively plays the roles of isolating stratum deformation and maintaining the underground water level of the building, can simultaneously reduce the influence of foundation pit earthwork excavation and in-pit precipitation in the stratum on the nearby sensitive building, and avoids the building from generating excessive settlement or inclination;

(2) The recharging well can effectively maintain the underground water level close to sensitive buildings around the water-rich sandy soil foundation pit, reduce consolidation settlement caused by the increase of the effective stress of the soil body and obviously reduce the influence caused by precipitation in the pit;

(3) The utility model discloses the division wall is the reinforced concrete material, and isolation pile has better wholeness relatively, can effectively avoid rich water sandy stratum medium sand granule to pass and keep apart the space between the stake and lead to soil erosion and water seriously, obviously cuts off the stratum deformation that foundation ditch excavation off-load arouses to reduce rich water sand foundation ditch excavation to closing on the influence of sensitive building.

Drawings

FIG. 1 is a schematic view of the position of the partition wall and the recharge well of the present invention;

FIG. 2 is a schematic view of the vertical surface of the isolation wall and the recharge well of the present invention;

FIG. 3 is a schematic diagram of a recharge well;

the reference numbers in the figures illustrate:

1. foundation pit, 2 isolation wall, 3 recharge well, 4 sensitive building, 5 sensitive building foundation, 6 cohesive soil, 7 clay ball, 8 medium coarse sand, 3-1 solid pipe, 3-2 bridge type filter pipe and 3-3 sedimentation pipe.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiment of the present invention is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

A protection structure of a sensitive building close to a foundation pit with water-rich sandy soil is shown in figures 1 and 2, is positioned between the foundation pit 1 and the sensitive building 4 and comprises a partition wall 2 and a recharge well 3, and the recharge well 3 is arranged between the partition wall 2 and the sensitive building 4.

The number of the recharging wells 3 is multiple, the recharging wells 3 are uniformly arranged at intervals along the direction parallel to the partition wall 2, the distance between every two adjacent recharging wells 3 is 4-8 m, the recharging pressure is 0.08MPa, and the recharging amount of a single well is not less than 9.0m ³ /h。

The separation wall 2 is a reinforced concrete wall, the distance between the wall and the sensitive building 4 is selected according to the excavation depth of the foundation pit 1, the form of the enclosure structure and the form of the sensitive building foundation 5, and the closer the excavation depth of the foundation pit 1 is, the poorer the supporting effect of the enclosure form is and the smaller the bearing capacity of the sensitive building foundation 5 is, the closer the separation wall 2 needs to be to the building.

Referring to fig. 3, the recharging well 3 is an incomplete well, the incomplete well adopts a bridge type filter pipe, the bridge type filter pipe sequentially comprises a solid pipe 3-1, a filtering section 3-2 and a sedimentation pipe 3-3 from top to bottom, the external diameter of the recharging well 3 is 650mm, the internal diameter is 273mm, the length of the sedimentation pipe is 1000mm, the length of the filtering section is not less than 10m, and specifically depends on the distribution condition of an aquifer, the external filler of the recharging well 3 is respectively cohesive soil 6, clay balls 7 and medium coarse sand 8 from top to bottom, wherein the cohesive soil 6 and the clay balls 7 play a role in hole sealing.

The construction process of the sensitive building protection structure close to the water-rich sandy soil foundation pit comprises the following steps:

s1, parameters such as length, thickness, rigidity and setting range of the partition wall and related parameters such as depth of the underground water recharging well and length of the filtering section are determined before construction according to the actual engineering situation and design requirements.

S2, before the foundation pit 1 is excavated, constructing a separation wall 2 according to the earlier design requirements, and specifically comprising the following steps:

s201, positioning and paying off: determining construction positions of a guide wall and a separation wall in an active area soil body between a foundation pit 1 and a sensitive building 4 according to design requirements;

s202, building a guide wall: constructing a guide wall as a guide of a subsequent groover, storing slurry and preventing the collapse of surface soil outside a pit;

s203, excavating groove sections: before digging a groove, dividing a partition wall into a plurality of construction groove sections in advance, wherein the length of each groove section is usually 3-7 m, and ensuring that the groove is filled with slurry all the time in the groove digging process;

s204, bottom cleaning and pulp changing: when the excavation in the groove section is finished, bottom cleaning and slurry changing in the groove section are carried out, and the purpose is to remove residual slurry residues at the bottom of the groove section until the relevant design requirements are met;

s205, hoisting a reinforcement cage;

s206, constructing a joint: in order to ensure the water-resisting property of the partition wall 2 in the water-rich sandy stratum, an I-shaped steel joint form is recommended;

s207, pouring concrete: the rising speed of concrete pouring is not less than 2m/h, the bottom of the guide pipe needs to be buried 2-4 m below the concrete surface, is not more than 6m, and is not less than 1m, the bottom of the guide pipe is strictly forbidden to be lifted out of the concrete surface, and in addition, the concrete material is required to be according to the design requirement;

s208, constructing the next groove section of the isolation wall 2, and repeating the corresponding construction steps;

and S3, measuring and lofting between the sensitive building 4 and the partition wall 2, marking the position of the corresponding coordinate point of each recharge well 3 on the ground surface according to the design coordinate, and then constructing the recharge wells 3 at the corresponding positions according to the design requirement.

The embodiment provides a protection structure for a sensitive building close to a water-rich sandy soil foundation pit, wherein a partition wall 2 with good integrity is arranged in a soil body of an active area between an existing sensitive building 4 and a foundation pit 1 to be excavated, the arrangement range of the partition wall 2 is determined according to the excavation influence range of the foundation pit 1, and the partition wall 2 can be fully utilized to partition stratum deformation caused by excavation unloading of the foundation pit 1, so that the influence of excavation of the water-rich sandy soil foundation pit 1 on the adjacent sensitive building is reduced, in addition, a recharging well 3 is arranged between the existing sensitive building 4 and the partition wall 2 to maintain the underground water level of the building, and the influence of precipitation in the pit on the sensitive building is effectively reduced.

The foregoing has described in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be devised by those skilled in the art in light of the principles of this invention without the use of inventive faculty. Therefore, the technical solutions that can be obtained by a person skilled in the art through logic analysis, reasoning or limited experiments based on the prior art according to the concepts of the present invention should be within the scope of protection defined by the claims.

Claims (7)

1. A sensitive building protection structure close to a foundation pit with water-rich sandy soil is positioned between a foundation pit (1) and a sensitive building (4), and is characterized by comprising a partition wall (2) and a recharging well (3), wherein the recharging well (3) is arranged between the partition wall (2) and the sensitive building (4);

the isolation wall (2) is a reinforced concrete wall;

the recharge well (3) is an incomplete well, and the incomplete well adopts a bridge type strainer;

and the outside of the recharging well (3) is provided with external recharging well fillers respectively comprising clay (6), clay balls (7) and medium coarse sand (8) from top to bottom.

2. A sensitive building protection structure near a water-rich sandy soil foundation pit according to claim 1, wherein the number of the recharge well (3) is plural.

3. A sensitive building protection structure near a water-rich sandy soil foundation pit according to claim 2, wherein a plurality of recharge wells (3) are arranged at intervals in a direction parallel to the partition wall (2).

4. A sensitive building protection structure near a water-rich sandy soil foundation pit according to claim 3, wherein the distance between adjacent recharge wells (3) is 4-8 m.

5. A sensitive building protection structure near a water-rich sandy soil foundation pit according to claim 2, wherein a plurality of recharging wells (3) are arranged at even intervals.

6. The protection structure for sensitive buildings near a water-rich sandy soil foundation pit as claimed in claim 1, wherein the bridge type water filtering pipe comprises a solid pipe (3-1), a filtering section (3-2) and a settling pipe (3-3) from top to bottom in sequence.

7. The sensitive building protection structure near the water-rich sandy soil foundation pit as claimed in claim 6, wherein the length of said filtering section is not less than 10m.

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