Foundation pit corner enclosure and underground water control structure

Abstract

The utility model belongs to the technical field of building and municipal construction, and particularly discloses a foundation pit corner enclosure and underground water control structure which comprises an underground diaphragm wall, a high-pressure jet grouting pile, an inclined strut and a dewatering well. The underground diaphragm wall is a surrounding wall body arranged on the periphery in the foundation pit, a wall bottom grouting pipe is arranged in the underground diaphragm wall, and a reserved grouting pipe is arranged at the position, located at the joint, outside the wall. The high-pressure jet grouting piles comprise corner inner high-pressure jet grouting piles and corner outer high-pressure jet grouting piles; the inclined strut comprises a triangular plate brace and an angle brace which are both mounted at the corner of the enclosing purlin, and the enclosing purlin is mounted on the inner circumference of the underground diaphragm wall; the multiple dewatering wells are arranged on the inner side of the corner inner high-pressure jet grouting pile and the outer side of the corner outer high-pressure jet grouting pile respectively. The problems of foundation pit corner deformation and underground water leakage are solved through a combined structure of triangular plate supports, angle supports, corner inner and outer high-pressure jet grouting pile reinforcement, dewatering, underground diaphragm wall seam reinforcement and wall bottom grouting.

Description

Technical Field

[0001] The utility model relates to the technical field of building and municipal construction, and in particular to a foundation pit corner enclosure and groundwater control structure. Background Art

[0002] During foundation pit construction, retaining structures are usually set up to ensure the safety of underground structure construction and the surrounding environment of the foundation pit. The most commonly used retaining structure is the underground continuous wall, which is formed by mechanical drilling and other means on the edge of the excavated foundation pit to form pile holes in the foundation soil, and then steel cages are placed in the pile holes and concrete is poured to form support piles. The support piles are fitted together to form a support wall.

[0003] Corner deformation during foundation pit excavation is often one of the important factors leading to foundation pit instability. Traditional retaining structures are difficult to completely avoid corner deformation problems, posing a safety hazard. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a foundation pit corner enclosure and groundwater control structure, which can avoid the deformation problem of the foundation pit corner, greatly improve the stability of the foundation pit structure, and ensure the safety of the foundation pit construction.

[0005] In order to achieve the above purpose, the specific technical solutions adopted by the utility model are as follows:

[0006] A foundation pit corner enclosure and groundwater control structure, comprising:

[0007] The underground continuous wall is an enclosing wall set around the foundation pit;

[0008] High-pressure rotary grouting piles, including high-pressure rotary grouting piles inside corners and high-pressure rotary grouting piles outside corners, which are respectively arranged inside and outside the corners of the underground continuous wall;

[0009] Diagonal braces, including triangular plate braces and angle braces, both installed at the corners of the perimeter purlins, the perimeter purlins are installed on the inner periphery of the underground continuous wall, and the installation position thereof is higher than the high-pressure jet grouting piles in the corners;

[0010] A plurality of dewatering wells are respectively provided on the inner side of the high-pressure rotary jet grouting pile inside the corner and on the outer side of the high-pressure rotary jet grouting pile outside the corner.

[0011] Preferably, the foundation pit corner enclosure and groundwater control structure further includes a wall bottom grouting pipe, the underground continuous wall is formed by connecting a plurality of unit wall segments, and the wall bottom grouting pipe is vertically arranged in each unit wall segment at the corner, and its bottom position is lower than the bottom end of the unit wall segment. Grouting the bottom of the continuous wall through the wall bottom grouting pipe can enhance the consolidation of the soil at the bottom of the wall, reduce the settlement of the wall, and reduce the lateral displacement of the wall, making the underground continuous wall more stable.

[0012] Preferably, at least two of the wall bottom grouting pipes are provided in each unit wall section at the corner.

[0013] Preferably, the foundation pit corner enclosure and groundwater control structure also includes a reserved grouting pipe, which is vertically arranged outside the corner of the underground continuous wall and located at the joint between the unit wall sections. The joint is a weak point of the underground continuous wall. A loose joint will affect the structural stability and water retaining capacity of the underground continuous wall. The reserved grouting pipe can fill the gap defects of the joint itself or generated during later use.

[0014] Preferably, at least two groups of the triangular plate supports and angle supports are arranged at intervals along the vertical direction to improve the internal support level.

[0015] Preferably, the bottoms of the underground continuous wall, high-pressure jet grouting piles and precipitation wells are all in the pressurized aquifer.

[0016] The utility model has the following beneficial effects:

[0017] 1. By setting high-pressure jet grouting piles inside and outside the underground continuous wall to reinforce the soil inside and outside the corners of the foundation pit, and setting triangular plate supports and angle supports to provide internal support for the corners, the stability of the corners of the foundation pit can be effectively improved and the possibility of deformation can be reduced.

[0018] 2. By setting a grouting pipe at the bottom of the underground continuous wall and a reserved grouting pipe outside the wall, the structural stability of the underground continuous wall can be ensured and the possibility of deformation at the corners of the foundation pit can be further reduced.

[0019] 3. Set up drainage wells inside and outside the corners of the underground continuous wall. On the one hand, pumping and drainage wells can be used to avoid the deterioration of soil stability and even sudden surges in the foundation pit caused by groundwater seepage, thereby effectively improving the stability of the corners of the foundation pit. On the other hand, the sealing of the underground continuous wall can be judged according to the changes in the water level in the drainage wells outside the wall, and the timing of grouting the reserved grouting pipes can be determined.

[0020] In summary, the utility model solves the problems of corner deformation and groundwater leakage of foundation pits through a combined structure of triangular plate supports, angle supports, high-pressure rotary jet pile reinforcement inside and outside the corners, dewatering, reinforcement of underground continuous wall seams, and grouting at the bottom of the wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 : The main view of the foundation pit corner enclosure and groundwater control structure described in Example 1.

[0022] Figure 2 : Figure 1 A partial enlarged schematic diagram of .

[0023] Figure 3 : An overhead view of the foundation pit corner enclosure and groundwater control structure described in Example 1.

[0024] Figure 4 : Figure 3 A magnified schematic diagram of center A.

[0025] In the figure: 1-underground continuous wall, 2-grouting pipe at the bottom of the wall, 3-reserved grouting pipe, 4-high-pressure rotary jet pile inside the corner, 5-high-pressure rotary jet pile outside the corner, 6-triangular plate support, 7-angle support, 8-dewatering well; Ⅰ-ground, Ⅱ-foundation pit, Ⅲ-pressure aquifer, Ⅳ-purlin, Ⅴ-counter support. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] A foundation pit corner enclosure and groundwater control structure, such as Figure 1-4 As shown, it is used for corner deformation and groundwater control of foundation pit II opened on the ground I. The structure includes an underground continuous wall 1, a wall bottom grouting pipe 2, a reserved grouting pipe 3, a high-pressure rotary jet pile, a diagonal brace and a dewatering well 8; the high-pressure rotary jet pile includes a corner inner high-pressure rotary jet pile 4 and a corner outer high-pressure rotary jet pile 5, and the diagonal brace includes a triangular plate brace 6 and an angle brace 7. The bottoms of the underground continuous wall 1, the wall bottom grouting pipe 2, the reserved grouting pipe 3, the high-pressure rotary jet pile and the dewatering well 8 are all in the confined aquifer III.

[0029] Specifically, the underground continuous wall 1 is an enclosing wall arranged around the foundation pit II, which is formed by connecting a plurality of unit wall sections; the wall bottom grouting pipe 2 is vertically arranged in each unit wall section at the corner, and its bottom position is about half a meter deeper than the bottom end of the unit wall section. Each unit wall section is about 6 meters long and is composed of a steel cage and concrete poured in the steel cage. During construction, pile holes are first driven, and then the steel cage is placed in the pile holes. Then, two wall bottom grouting pipes 2 are placed in each steel cage, and concrete is poured. After the curing period, grouting is injected into the wall bottom grouting pipe 2 to achieve grouting reinforcement of the continuous wall 1.

[0030] The reserved grouting pipe 3 is vertically arranged at the joint of adjacent unit wall sections of the underground continuous wall 1 and arranged outside the corner of the underground continuous wall 1, and its pipe body is provided with a plurality of drainage holes. The reserved grouting pipe 3 is used to seal when a gap appears at the wall joint to prevent groundwater from leaking or even gushing due to cracks.

[0031] The high-pressure rotary jet grouting piles 4 inside the corner and the high-pressure rotary jet grouting piles 5 outside the corner are respectively arranged inside and outside the corner of the underground continuous wall 1 to reinforce the soil inside and outside the corner of the foundation pit.

[0032] Two supports are provided above the high-pressure jet grouting piles 4 in the corners in the enclosed area of ​​the underground continuous wall 1, and each support includes a purlin IV installed on the inner peripheral wall of the underground continuous wall 1 and a brace V inscribed in the purlin IV. The triangular plate brace 6 and the angle brace 7 are installed at the corners of each purlin IV to provide multiple internal supports for each corner of the foundation pit II in the vertical direction.

[0033] The dewatering wells 8 are respectively provided with a plurality of inner sides of the high-pressure rotary jet piles 4 inside the corner and outer sides of the high-pressure rotary jet piles 5 outside the corner. The pumping pipe is extended into the well pipe of the dewatering well 8 to carry out dewatering and pressure reduction, thereby avoiding groundwater leakage and sudden surge, and avoiding corner deformation caused by them.

[0034] The above-mentioned foundation pit corner enclosure and groundwater control structure provides internal support through triangular plate supports 6 and angle supports 7, and the soil is reinforced by high-pressure rotary spray columns inside and outside the corners. The bottom grouting and wall joint reinforcement of the underground continuous wall 1 are carried out through the wall bottom grouting pipe 2 and the reserved grouting pipe 3. The water is lowered and the pressure is reduced through the internal and external dewatering wells 8. Such combined measures can effectively solve the deformation problem of the foundation pit corners and improve the safety of foundation pit construction.

[0035] This specific implementation method is only an explanation of the utility model, not a limitation of the utility model. Any changes made by those skilled in the art after reading the specification of the utility model will be protected by the patent law as long as they are within the scope of the claims of the utility model.

Claims

1. A foundation pit corner enclosure and groundwater control structure, characterized in that: include: The underground continuous wall (1) is an enclosing wall arranged around the foundation pit (II); The high-pressure rotary jet piles include high-pressure rotary jet piles (4) inside the corner and high-pressure rotary jet piles (5) outside the corner, which are respectively arranged inside and outside the corner of the underground continuous wall (1); Diagonal braces, including triangular plate braces (6) and angle braces (7) both installed at the corners of the perimeter purlin (IV), the perimeter purlin (IV) being installed on the inner periphery of the underground continuous wall (1), and being arranged at a position higher than the high-pressure jet grouting piles (4) in the corners; A plurality of dewatering wells (8) are respectively provided on the inner side of the high-pressure rotary grouting pile (4) inside the corner and on the outer side of the high-pressure rotary grouting pile (5) outside the corner.

2. The foundation pit corner enclosure and groundwater control structure according to claim 1 is characterized by: It also comprises a wall bottom grouting pipe (2), the underground continuous wall (1) is formed by connecting a plurality of unit wall segments, the wall bottom grouting pipe (2) is vertically arranged in each of the unit wall segments at the corners, and its bottom position is arranged lower than the bottom end of the unit wall segment.

3. The foundation pit corner enclosure and groundwater control structure according to claim 2 is characterized by: At least two wall bottom grouting pipes (2) are arranged in each unit wall section at the corner.

4. The foundation pit corner enclosure and groundwater control structure according to claim 2, characterized in that: It also comprises a reserved grouting pipe (3), which is vertically arranged outside the corner of the underground continuous wall (1) and located at the joint between the unit wall sections.

5. The foundation pit corner enclosure and groundwater control structure according to claim 1, characterized in that: At least two groups of the triangular plate supports (6) and angle supports (7) are arranged at intervals along the vertical direction.

6. The foundation pit corner enclosure and groundwater control structure according to claim 1, characterized in that: The bottoms of the underground continuous wall (1), high-pressure jet grouting piles and dewatering wells (8) are all located in the pressurized aquifer (III).

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