Structural system combining stress release and in-pit reinforcement of foundation pit
By pre-embedding of grouted steel pipes and loose gravel in the stress release hole, and injecting cement slurry into the solidification area after the prefabricated pile construction is completed, the foundation pit instability problem caused by prefabricated pile construction is solved, and an efficient and economical foundation pit reinforcement effect is achieved.
Patent Information
- Application Number
- CN202422336780.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-05-16
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The soil extrusion effect and excessive void water pressure brought about by prefabricated pile construction lead to unstable foundation pits, and the existing stress relief hole reinforcement methods are costly and have a long construction period.
The grouted steel pipe is pre-embedded in the stress relief hole and filled with loose gravel. After the construction of the prefabricated piles is completed, cement slurry and loose gravel are injected into the grouted steel pipe to solidify, forming a reinforcement area within the foundation pit, and combining the outer support piles to form a new support structure system.
Effectively eliminate soil extrusion effect and over-space water pressure, improve foundation pit stability and control deformation ability, reduce construction costs and construction period, and form a high-strength pit reinforcement area.
Smart Images
Figure CN222878678U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of geotechnical engineering, in particular to a structural system combining stress release with reinforcement in a foundation pit. Background Art
[0002] Precast piles have the advantages of low engineering cost, fast construction speed, civilized and clean construction site, etc., and are widely used in the foundation of various civil construction, hydraulic, municipal and other projects. Precast piles are generally driven by static pressure or hammering. Since they are constructed without taking soil, as the precast piles continue to sink into the soil, soil squeezing effect and excess pore water pressure are caused. As a result, the ground is vertically lowered, and the deep soil moves horizontally outward along the pile circumference. This causes cracks in surrounding roads, buildings (structures), and municipal pipeline ruptures and other safety accidents. Before the construction of precast piles, stress relief holes are often set between the precast engineering piles and the supporting piles, and the holes are filled with loose sand or gravel to eliminate the soil squeezing effect and excess pore water pressure caused by the construction of precast piles. Since the stress relief holes are empty for taking soil and the filling material in the holes is loose, it will cause disturbance of the soil in the pit, reduce the strength of the soil in the pit inside the supporting piles, and have an adverse effect on the stability of the foundation pit and the ability to control deformation. The use of high-pressure jet grouting piles or mixing piles to reinforce stress release holes is costly, uneconomical, and takes a long time. Utility Model Content
[0003] Purpose of the utility model: The utility model mainly solves the current technical problems of unsafe foundation pits and high processing costs caused by the construction of stress release holes, and proposes a structural system combining stress release with reinforcement in the foundation pit. By pre-burying grouting steel pipes in the stress release holes and filling them with loose gravel, after the construction of prefabricated engineering piles is completed, before the foundation pit is excavated, cement slurry and loose gravel are injected into the grouting steel pipes to solidify to form a reinforcement area in the foundation pit. The reinforcement area in the pit and the outer supporting piles form a new support structure system to control the deformation of the foundation pit, protect the safety of the surrounding environment of the foundation pit, and avoid accidents.
[0004] In order to solve the above technical problems, the utility model proposes: a structural system combining stress release and reinforcement in the foundation pit, including: stress release holes 10, grouting steel pipes 20, loose gravel 30, prefabricated engineering piles 40, water-stop curtains 50, support piles 60, crown beams 70, bottom plate cushions 80, basement bottom plates 90, and basement exterior walls 100.
[0005] A water-stop curtain 50 is provided on one side of the support pile 60, and a stress release hole 10 is provided on the other side; the upper part of the other side of the stress release hole 10 is the basement outer wall 100, and the lower part of the other side of the stress release hole 10 is the prefabricated engineering pile 40;
[0006] The basement exterior wall 100 is arranged on the basement floor 90; the basement floor 90 is located above the floor cushion layer 80;
[0007] The top of the prefabricated engineering pile 40 is fixedly connected to the basement floor 90 and the floor cushion 80 to form a foundation;
[0008] The basement floor 90 and the floor cushion 80 are respectively fixedly connected to one side of the support pile 60;
[0009] The stress release hole 10 is arranged between the prefabricated engineering pile 40 and the support pile 60; the grouting steel pipe 20 is pre-buried in the stress release hole 10; the top of the grouting steel pipe 20 is higher than the ground to prevent soil from falling in and clogging; the stress release hole 10 is filled with loose gravel 30; after the construction of the prefabricated engineering pile 40 is completed, cement slurry 203 is injected into the grouting steel pipe 20; the cement slurry 203 flows out through the grouting hole 201 and solidifies with the loose gravel 30 to form a reinforcement area in the foundation pit;
[0010] The upper end of the supporting pile 60 is fixedly connected to the crown beam 70; the water-stop curtain 50 is arranged on the outside of the supporting pile 60 to prevent water outside the pit from flowing into the foundation pit; the reinforcement area in the pit and the outer supporting piles 60, the crown beam 70 on the top of the supporting pile, and the water-stop curtain 50 form a new supporting structure system, that is, a structural system combining stress release and reinforcement in the foundation pit.
[0011] The water-stop curtain (50) is a cement-soil continuous wall structure, the support piles 60 are arranged vertically; the stress release holes 10 are arranged vertically in two rows, and the distance between two adjacent stress release holes 10 in each row is equidistant; and the stress release holes 10 in two adjacent rows are arranged in a staggered plum blossom shape.
[0012] The release hole 10 is pre-buried with a grouting steel pipe 20 and filled with loose gravel 30 and is constructed before the prefabricated engineering pile 40 to eliminate the soil squeezing effect and excess pore water pressure caused by the construction of the prefabricated engineering pile 40 and protect the safety of the surrounding environment.
[0013] The water-stop curtain 50 and the support pile 60 are constructed after the construction of the prefabricated engineering pile 40 is completed and the soil squeezing effect and the excess pore water pressure are eliminated, so as to prevent the soil squeezing effect of the prefabricated engineering pile 40 from causing the support pile 60 to deflect and the water-stop curtain 50 to crack;
[0014] The top of the grouting steel pipe 20 is higher than the ground to prevent soil from falling in and clogging it. Grouting holes 201 are arranged at intervals in the lower part, ranging from below the basement floor 90 to the bottom of the grouting steel pipe 20. Cement slurry 203 flows out through the grouting holes 201 and mixes with loose gravel 30 to consolidate. Angle steel barbs 202 are arranged at the grouting holes 201 to prevent soil from clogging.
[0015] The loose gravel 30 is filled from the bottom of the stress relief hole 10 to the ground.
[0016] After the foundation pit is excavated to the bottom, the grouting steel pipe 20 is cut off, and the cutting range is the part above the bottom plate cushion layer 80 to the ground, and then recycled.
[0017] The implementation steps are as follows:
[0018] First, a stress release hole 10 is constructed by a hole-forming machine and the soil in the hole is removed, and a grouting steel pipe 20 is pre-buried, the top of the grouting steel pipe 20 is higher than the ground, and the bottom reaches the bottom of the stress release hole 10;
[0019] Further, loose gravel 30 is filled into the stress release hole 10 to the ground;
[0020] Further, constructing prefabricated engineering piles 40;
[0021] Further, after the construction of the prefabricated engineering piles 40 is completed and the soil squeezing effect and the excess pore water pressure dissipate, the water-stop curtain 50 and the support piles 60 are constructed;
[0022] Further, after the construction of the support piles 60 is completed, the support piles 60 are constructed to top the crown beam 70;
[0023] Further, cement slurry 203 is injected into the grouting steel pipe 20, and the cement slurry 203 flows out through the grouting hole 201 and solidifies with the loose gravel 30 to form a reinforcement area in the foundation pit;
[0024] Further, after the reinforced area in the pit reaches the strength, the foundation pit is opened to the bottom of the pit, and the grouting steel pipe 20 is cut out, ranging from above 80 of the bottom plate cushion layer to the ground, and recycled;
[0025] Furthermore, the construction floor cushion layer 80, the basement floor 90 and the prefabricated engineering piles 40 are fixedly connected to form a foundation.
[0026] Beneficial effects: In order to eliminate the soil squeezing effect and excess pore water pressure caused by the sinking of precast engineering piles, stress release holes are usually set between the precast engineering piles and the supporting piles, and the holes are filled with loose materials. After the construction of the precast engineering piles is completed, the loose material in the release holes will cause disturbance of the soil in the pit, reducing the strength of the soil in the pit inside the supporting piles, affecting the bearing capacity of the supporting piles, and having an adverse effect on the stability of the foundation pit and the ability to control deformation; if high-pressure rotary jet piles or mixing piles are used to reinforce the stress release holes, the cost is high, uneconomical, and the construction period is long. The utility model provides a structural system combining stress release with reinforcement in the foundation pit. After the construction of the prefabricated engineering piles is completed, cement slurry and loose gravel are injected into the grouting steel pipe to solidify to form a reinforcement area in the foundation pit before the foundation pit is excavated. The reinforcement area in the pit and the outer supporting piles form a new structural system to control the deformation of the foundation pit, which not only solves the current safety and technical problems caused by the construction of stress release holes, but also solves the problem that it is uneconomical and takes a long time to reinforce the stress release holes by using high-pressure jet grouting piles or mixing piles. This structural system has the advantages of simple operation, low engineering cost, saving construction time, high reinforcement strength in the pit, and strong ability to control the deformation of the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 It is a cross-sectional view of a structural system that combines stress relief with reinforcement in the foundation pit;
[0028] Figure 2 It is a plan view of a structural system combining stress release with reinforcement in the foundation pit;
[0029] Figure 3 It is the plane projection diagram of the stress relief hole;
[0030] Figure 4 It is a side projection diagram of the grouting steel pipe.
[0031] In the figure: 10, stress relief hole; 20, grouting steel pipe; 201, grouting hole; 202, angle steel barb; 203, cement slurry; 30, loose gravel; 40, precast engineering pile; 50, water-stop curtain; 60, supporting pile; 70, crown beam; 80, bottom plate cushion; 90, basement bottom plate; 100, basement exterior wall. DETAILED DESCRIPTION
[0032] The present invention is further explained in detail below in conjunction with the accompanying drawings. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention by those skilled in the art (including but not limited to support form, number of stress release holes, grouting form) all fall within the scope defined by the claims attached to this application.
[0033] refer to Figure 1-4 As shown, the utility model provides a structural system combining stress release and pit reinforcement:
[0034] in Figure 1 It is a cross-sectional view of a structural system that combines stress relief with reinforcement in the foundation pit; Figure 2 A schematic plan view of a structural system combining stress release with reinforcement in a foundation pit; Figure 3 It is the plane projection diagram of the stress relief hole; Figure 4 It is a side projection diagram of a grouting steel pipe; the utility model structural system includes: a stress release hole 10, a grouting steel pipe 20, loose gravel 30, a prefabricated engineering pile 40, a water-stop curtain 50, a supporting pile 60, a crown beam 70, a bottom plate cushion 80, a basement bottom plate 90, and a basement outer wall 100.
[0035] A water-stop curtain 50 is arranged on one side of the support pile 60 , and a stress release hole 10 is arranged on the other side; the upper part of the other side of the stress release hole 10 is the basement outer wall 100 , and the lower part of the other side of the stress release hole 10 is the prefabricated engineering pile 40 .
[0036] The stress release hole 10 is arranged between the prefabricated engineering pile 40 and the supporting pile 60; the grouting steel pipe 20 is pre-buried in the stress release hole 10; the top of the grouting steel pipe 20 is higher than the ground to prevent soil from falling in and clogging; the stress release hole 10 is filled with loose gravel 30; after the construction of the prefabricated engineering pile 40 is completed, cement slurry 203 is injected into the grouting steel pipe 20; the cement slurry 203 flows out through the grouting hole 201 and solidifies with the loose gravel 30 to form a reinforcement area in the foundation pit.
[0037] The upper end of the supporting pile 60 is fixedly connected to the crown beam 70; the water-stop curtain 50 is arranged on the outside of the supporting pile 60 to prevent water outside the pit from flowing into the foundation pit; the reinforced area in the pit and the outer supporting pile 60, the crown beam 70 on the top of the supporting pile, and the water-stop curtain 50 form a new supporting structure system.
[0038] The water-stop curtain (50) is a cement-soil continuous wall structure, the support piles 60 are arranged vertically; the stress release holes 10 are arranged vertically in two rows, and the distance between two adjacent stress release holes 10 in each row is equidistant; and the stress release holes 10 in two adjacent rows are arranged in a staggered plum blossom shape.
[0039] The release hole 10 is constructed before the prefabricated engineering pile 40 to eliminate the soil squeezing effect and excess pore water pressure caused by the construction of the prefabricated engineering pile 40 and protect the safety of the surrounding environment.
[0040] The water-stop curtain 50 and the supporting piles 60 are constructed after the construction of the prefabricated engineering piles 40 is completed and the soil squeezing effect and the excess pore water pressure are eliminated, so as to prevent the supporting piles 60 from being deflected and the water-stop curtain 50 from being cracked due to the soil squeezing effect during the construction of the prefabricated engineering piles 40 .
[0041] The top of the grouting steel pipe 20 is higher than the ground to prevent soil from falling in and clogging it. Grouting holes 201 are arranged at intervals in the lower part, ranging from below the basement floor 90 to the bottom of the grouting steel pipe 20. Cement slurry 203 flows out through the grouting holes 201 and is mixed and consolidated with loose gravel 30. Angle steel barbs 202 are arranged at the position of the grouting holes 201 to prevent soil from clogging it.
[0042] The loose gravel 30 is filled from the bottom of the stress relief hole 10 to the ground.
[0043] The basement exterior wall 100 is disposed on a basement floor 90 ; the basement floor 90 is located above a floor cushion layer 80 .
[0044] The top of the prefabricated engineering pile 40 is fixedly connected to the basement floor 90 and the floor cushion 80 to form a foundation.
[0045] The basement floor 90 and the floor cushion 80 are respectively fixedly connected to one side of the support pile 60 .
[0046] After the foundation pit is excavated to the bottom, the grouting steel pipe 20 is cut off, and the cutting range is the part above the bottom plate cushion layer 80 to the ground, and then recycled.
[0047] The specific construction steps are as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown in FIG. , a stress release hole 10 is first constructed by a hole-forming machine and the soil in the hole is taken out, and a grouting steel pipe 20 is pre-buried. The top of the grouting steel pipe 20 is higher than the ground, and the bottom is at the bottom of the stress release hole 10.
[0048] The stress relief hole 10 is then filled with loose gravel 30 until it reaches the ground.
[0049] Then the prefabricated engineering piles are sunk 40 meters into the soil by static pressure or hammering.
[0050] After the construction of the prefabricated engineering piles 40 is completed and the soil squeezing effect and the excess pore water pressure are dissipated, the water-stop curtain 50 and the supporting piles 60 are constructed.
[0051] The supporting piles 60 and the crown beam 70 are then cast.
[0052] Before excavation of the foundation pit, cement slurry 203 is injected into the grouting steel pipe 20. The cement slurry 203 flows out through the grouting hole 201 and solidifies with the loose gravel 30 to form a reinforcement area in the foundation pit.
[0053] After the reinforced area in the pit reaches the required strength, the foundation pit earthwork is opened to the bottom of the pit, and the grouting steel pipe 20 is cut off, ranging from above 80 of the bottom plate cushion layer to the ground, and then recycled.
[0054] The bottom plate cushion layer 80 and the basement bottom plate 90 are then fixedly connected with the prefabricated engineering piles 40 to form a foundation.
[0055] This can solve the existing problems of reduced soil strength inside the support piles due to the construction of stress release holes, affecting the bearing capacity of the support piles, and increasing costs, being uneconomical, and having a long construction period caused by adopting other measures such as high-pressure rotary grouting and mixing piles to reinforce the stress release holes.
Claims
1. A structural system combining stress release and pit reinforcement, comprising: Stress relief hole (10), grouting steel pipe (20), loose gravel (30), prefabricated engineering pile (40), water-stop curtain (50), support pile (60), crown beam (70), bottom plate cushion (80), basement bottom plate (90), basement outer wall (100); The invention is characterized in that: a water-stop curtain (50) is arranged on one side of the support pile (60), and a stress release hole (10) is arranged on the other side; the upper part of the other side of the stress release hole (10) is the basement outer wall (100), and the lower part of the other side of the stress release hole (10) is the prefabricated engineering pile (40); The basement exterior wall (100) is arranged on the basement floor (90); the basement floor (90) is located above the floor cushion layer (80); The top of the prefabricated engineering pile (40) is fixedly connected to the basement floor (90) and the floor cushion (80) to form a foundation; The basement floor (90) and the floor cushion (80) are respectively fixedly connected to one side of the support pile (60); The stress release hole (10) is arranged between the prefabricated engineering pile (40) and the support pile (60); a grouting steel pipe (20) is pre-buried in the stress release hole (10); the top of the grouting steel pipe (20) is higher than the ground to prevent soil from falling in and clogging; the stress release hole (10) is filled with loose gravel (30); after the construction of the prefabricated engineering pile (40) is completed, cement slurry (203) is injected into the grouting steel pipe (20); the cement slurry (203) flows out through the grouting hole (201) and solidifies with the loose gravel (30) to form a reinforcement area in the foundation pit; The upper ends of the support piles (60) are fixedly connected to the crown beams (70); the water-stopping curtains (50) are arranged outside the support piles (60) to prevent water outside the pit from flowing into the foundation pit; the reinforcement area inside the foundation pit, the outer support piles (60), the crown beams (70) on the tops of the support piles, and the water-stopping curtains (50) form a new support structure system, i.e., a structural system combining stress release with reinforcement inside the foundation pit.
2. A structural system combining stress release and pit reinforcement according to claim 1, characterized in that: The water-stop curtain (50) is a cement-soil continuous wall structure, and the support piles (60) are arranged vertically; the stress release holes (10) are arranged vertically in two rows, and the distance between two adjacent stress release holes (10) in each row is equidistant; Two adjacent rows of stress release holes (10) are arranged alternately in a plum blossom shape.
3. A structural system combining stress release and pit reinforcement according to claim 1, characterized in that: The release hole (10) is pre-buried with a grouting steel pipe (20) and filled with loose gravel (30) and is constructed before the prefabricated engineering pile (40) is constructed, so as to eliminate the soil squeezing effect and excess pore water pressure caused by the construction of the prefabricated engineering pile (40) and protect the safety of the surrounding environment.
4. The structural system combining stress release and pit reinforcement according to claim 1 is characterized in that: The water-stop curtain (50) and the support piles (60) are constructed after the construction of the prefabricated engineering piles (40) is completed and the soil squeezing effect and the excess pore water pressure are eliminated, so as to prevent the support piles (60) from being deflected and the water-stop curtain (50) from being cracked due to the soil squeezing effect during the construction of the prefabricated engineering piles (40).
5. The structural system combining stress release and pit reinforcement according to claim 1, characterized in that: The top of the grouting steel pipe (20) is higher than the ground to prevent soil from falling in and clogging it. Grouting holes (201) are arranged at intervals in the lower part, ranging from below the basement floor (90) to the bottom of the grouting steel pipe (20). Cement slurry (203) flows out and mixes with loose gravel (30) for consolidation. Angle steel barbs (202) are arranged at the positions of the grouting holes (201) to prevent soil from clogging them.
6. The structural system combining stress release and pit reinforcement according to claim 1, characterized in that: The loose gravel (30) is filled from the bottom of the stress release hole (10) to the ground.
7. The structural system combining stress release and pit reinforcement according to claim 1, characterized in that: After the foundation pit is excavated to the bottom, the grouting steel pipe (20) is cut off, and the cutting range is the part above the bottom plate cushion layer (80) to the ground.