Method for lifting and restoring subsided foundations of deep plant equipment

Abstract

This application relates to a method for lifting and restoring the subsidence of deep plant equipment foundations, which belongs to the technical field of preventing foundation subsidence and correcting displacement, and it is based on the ratio of the compressive elastic modulus of the supporting layer to the base layer, i.e., E S1 / E S2 and Z / b, S1 determining the ground pressure diffusion angle based on the value of Z / b; S2 determining the load diffusion range based on the ground pressure diffusion angle; S3 using slurry injection to reinforce the unstable soil body in the soft base layer based on the load diffusion range, to form a slurry injection reinforcement body; S4 using slurry injection to reinforce the bearing layer according to the load diffusion range, and arranging slurry injection holes distributed on both sides of the equipment foundation along the two triangular areas of the direction line of the stress diffusion angle; S5 using slurry injection to reinforce within the middle range of the bearing layer to lift it; and S6 creating an irregular composite ground support at the bottom of the soft base layer, this application achieves the effects of providing deep reinforcement for the foundation, saving materials, and ensuring that the foundation meets the requirements of permanent settlement stability and displacement correction.

Description

[Technical Field]

[0001] The present application relates to the technical field of preventing foundation subsidence and correcting displacement, and in particular to a method for lifting and restoring the foundation of deep-seated plant equipment. [Background technology]

[0002] In recent years, with the rapid development of our country's construction industry, equipment foundations have become an increasingly widespread component of construction. Some equipment foundations have a series of characteristics, such as large diameter, large volume, and large additional stress on the ground. In addition, if the selected ground is relatively weak or backfilling problems occur, the equipment foundations are likely to settle unevenly. This situation not only significantly delays the progress of construction, but is also likely to cause property losses and even casualties.

[0003] There are many reasons why equipment foundations settle unevenly, but simply put, they can be divided into external and internal factors. External factors are mainly due to the ground conditions at the construction site, and uneven settlement of equipment foundations can be caused by a series of ground problems, such as the selected ground being too weak, the soil quality of the ground being uneven, or the backfill soil not being sufficiently compacted. Rainfall, earthquakes, changes in groundwater levels, etc. can also cause uneven settlement of equipment foundations. Internal factors include excessive load on the equipment itself that exceeds the design calculation value, or the placement of equipment foundations being too close together, which can easily cause uneven settlement of equipment foundations.

[0004] The currently most commonly used measures to address the problem of plant equipment foundation settlement include statically driving in piles with anchor rods and reinforcing with slurry injection. A Chinese patent with publication number CN112343078A is currently available for reference, which discloses a method for precisely lifting plant equipment foundations. This patent involves lifting plant equipment foundations in three steps. S1: In forming the curtain wall, holes are drilled vertically downward on both sides of the equipment that need to be lifted to form curtain holes, and slurry is injected into the curtain holes to form two parallel curtain walls; S2: In forming the reinforcement, slurry injection holes are arranged diagonally downward along the length of the curtain wall at the outer edge of the equipment, and slurry is injected into the slurry injection holes. Slurry is then injected into the slurry injection holes at the bottom of the base plate of the equipment foundation between the two curtain walls to form a reinforcement attached to the underside of the base plate, which is combined with the two curtain walls to form a U-shaped structure; S3: In lifting, holes are drilled downward using the slurry injection holes as lifting holes, and excavated below the reinforcement and between the two curtain walls. Slurry is injected under pressure into the bottom of the lifting holes to fill and reinforce the surrounding backfill layer, and then slurry is injected under pressure using retreating slurry injection to lift the equipment to the set lifting height.

[0005] Compared to the above-mentioned conventional techniques, the inventor believes that this technique has a clear advantage in lifting shallow subsidence of equipment ground, but has the disadvantage that a large amount of slurry injection material is required to reinforce and lift deep layers of equipment foundations, resulting in material waste. Summary of the Invention [Problem to be solved by the invention]

[0006] In order to achieve the effect of deep reinforcement of foundations, saving materials and ensuring that the foundations meet the requirements of permanent settlement stability and deviation correction, this application provides a method for lifting and restoring the settlement of deep plant equipment foundations. [Means for solving the problem]

[0007] The method for lifting and restoring the subsidence of deep plant equipment foundation according to the present application adopts the following technical solution.

[0008] The ratio of the compressive elastic modulus of the support layer to that of the soft base layer, i.e., E S1 / E S2 S1, which determines the ground pressure diffusion angle based on the value of Z / b; S2 determines the load diffusion range based on the ground pressure diffusion angle; S3: Reinforce the unstable soil body in the soft base layer by slurry injection based on the load diffusion range, and form a slurry injection reinforcement body; S4: Reinforce the bearing layer by injecting slurry according to the load diffusion range, and arrange slurry injection holes distributed on both sides of the equipment foundation along the two triangular areas of the direction line of the stress diffusion angle; S5: Reinforcement by slurry injection within the middle of the bearing layer and lifting it up; and S6 to create an irregular composite ground support at the bottom of the soft base.

[0009] The above technical solution determines the slurry injection range based on the load force transmission mechanism. To determine the slurry injection range, the stress diffusion angle must first be determined. When the foundation receives a load from above and transmits it to the bearing layer, the bearing layer is responsible for gradually and evenly distributing the load across the earth's crust. This distribution method is diffusion, and the range gradually expands downward at a certain angle according to the diffusion rule. This diffusion angle is the stress diffusion angle. The magnitude of the stress diffusion angle is determined in step S1. Once the slurry injection range is determined, a significant saving of slurry injection material is achieved, and an irregular composite ground support is formed at the bottom of the bearing layer, fulfilling the roles of support and anti-subsidence. In step S5, lifting is performed by injecting slurry into the middle of the bearing layer to prevent subsidence and lift and correct the ground position. Finally, the overall technology achieves deep reinforcement of the foundation, saves materials, and ensures the foundation meets the requirements of permanent settlement stability and displacement correction.

[0010] Optionally, the composite ground support in step S6 is a combination of two inclined slurry injection passages, and there is an intersection between the two inclined slurry injection passages.

[0011] By adopting the above technical solution, the composite ground support is formed by the cross-injection method, which is easy to operate and meets the construction needs. Secondly, the two slurry injection channels form an intersection, which is further combined with the reinforcement formed in step S3 to finally form a stable triangular support, which provides stable support to the upper bearing layer.

[0012] Optionally, the composite ground supports are provided in spaced-apart sets.

[0013] By adopting the above technical solution, multiple sets of composite ground supports are installed to reinforce the supporting effect on the upper supporting layer, and the spacing between them reduces the disturbance between the composite ground supports and the disturbance to the upper foundation during construction.

[0014] Optionally, in step S6, after the slurry injection into all the inclined passages is completed, a secondary reinforcing slurry injection is carried out at the intersection of the slurry injection passages.

[0015] By adopting the above technical solution, secondary slurry injection is performed at the intersection of the slurry injection passages, thereby ensuring stable force transmission at the intersection.

[0016] Optionally, in step S6, a secondary reinforcing slurry injection is performed at the intersections of all the slurry injection passages, and the secondary slurry injection areas at the intersections of adjacent slurry injection passages are interdigitated and overlap each other.

[0017] By adopting the above technical solution, the reinforcing bodies formed by the secondary slurry injection overlap and interlock with each other, thereby integrating all of the composite ground supports, avoiding the phenomenon of some composite ground supports settling independently, and after integration, further strengthening the support for the upper foundation and the effect of preventing the upper foundation from settling.

[0018] Optionally, in step S4, a retreat type slurry injection process integrated with excavation and injection is adopted, and the excavation is retreated one step for each lifting, and the slurry is injected one step.

[0019] By adopting the above technical solution, the backward slurry injection process can reduce disturbance to the strata outside the triangular area, and the backward injection makes it easier to withdraw the drill rod.

[0020] Optionally, the reinforcement formed by the interlocking overlapping secondary slurry injections at the intersections of adjacent slurry injection passages is generally horizontal.

[0021] By adopting the above technical solution, the horizontal reinforcing body is in a state where it exhibits the maximum strength-bearing surface, and the presence of the reinforcing body can be made to exert the maximum effect.

[0022] Alternatively, Z / b in step S1 can be used with a difference value between 0.25 and 0.5.

[0023] Optionally, in step S4, adjacent slurry injection holes are distributed at intervals.

[0024] By adopting the above technical solution, the slurry injection holes are distributed at intervals to reduce disturbance to areas other than the ground triangle.

[0025] Optionally, the vertical projection of the slurry injection reinforcement formed in the support layer is located entirely on the slurry injection reinforcement formed in the weak base layer.

[0026] By adopting the above technical solution, the limitation on the projection of the slurry injection reinforcement formed in the supporting layer is actually a limitation on the area of ​​the slurry injection reinforcement formed in the soft base, and the slurry injection reinforcement formed in the soft base can fully support the supporting layer above it. [Effects of the Invention]

[0027] As mentioned above, the present application includes at least one of the following beneficial technical effects. 1. By determining the slurry injection range based on the load force transmission mechanism, the amount of slurry injection material can be significantly reduced. By creating an irregular composite ground support at the bottom of the bearing layer, the settlement problem of deep plant equipment foundations can be solved. 2. The cross-shaped composite ground support, combined with the slurry injection reinforcement formed in the soft base, forms a stable triangular support, which prevents settlement and provides stable support for the equipment foundation. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a schematic diagram of the structure of an embodiment of the present application; [Figure 2] 1 is a diagram showing the state in which a support layer and a reinforcement body in a weak base layer are formed. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present application will be described in further detail below in conjunction with FIGS.

[0030] The embodiments of the present application disclose a method for lifting and restoring subsidence of a deep plant equipment foundation.

[0031] Referring to Figures 1 and 2, the method for lifting and restoring deep plant equipment foundation subsidence includes the following steps:

[0032] In S1, the ratio of the compressive elastic modulus of the support layer 4 to the soft base layer 5, i.e., E S1 / E S2, and Z / b, the ground pressure diffusion angle, i.e., θ, is determined. To determine the slurry injection range, the stress diffusion angle must first be determined. When the foundation 3 receives a load from above and transmits the load to the ground bearing layer 4, the ground bearing layer 4 is responsible for gradually dispersing the load and transmitting it evenly to the earth's crust. This gradual dispersion method is diffusion, and the diffusion rule is to gradually expand the range downward at a certain angle. The ground pressure diffusion angle is determined based on the "Ground and Foundation Design Code."

[0033] Ground pressure diffusion angle: JPEG2026508538000002.jpg35169where, E S1 is the compressive elastic modulus of the upper soil, and E S2 is the compressive modulus of the subsoil, Z refers to the depth from the calculation point to the base, and b refers to the width of the base of the foundation.

[0034] If Z / b<0.25, θ=0° and must be determined by testing as necessary; if Z / b>0.50, the θ value remains unchanged.

[0035] Z / b can be used with a difference value between 0.25 and 0.50, and if ES1 / ES2 is 3, Z / b is calculated as 0.375, and the corresponding θ is 14.5°.

[0036] In S2, the load diffusion range is determined based on the ground pressure diffusion angle, and based on the value of θ, the area extending downward to the soft base layer 5 and spanning the entire bearing layer 4 is the range of load transfer and diffusion.

[0037] In S3, based on the load diffusion range, the unstable soil body in the soft base layer 5 is reinforced by slurry injection to form a slurry injection reinforcement body.

[0038] In step S4, the bearing layer 4 is reinforced by slurry injection according to the load diffusion range, and slurry injection holes are arranged at intervals on both sides of the equipment foundation 3 along the two triangular areas of the direction line of the stress diffusion angle. A retreat-type slurry injection process integrated with excavation and injection is used during slurry injection, retreating one step for each lifting and injecting one step of slurry. After the slurry injection is completed, it is necessary to ensure that the vertical projection of the slurry injection reinforcement formed in the bearing layer 4 is completely positioned on the slurry injection reinforcement formed in the soft base layer 5.

[0039] In S5, slurry is injected into the middle area of ​​the support layer 4 to reinforce and lift it.

[0040] In step S6, an irregular composite ground support 6 is constructed at the bottom of the soft base 5. The composite ground support 6 is a combination of two inclined slurry injection passages, and the two inclined slurry injection passages have intersections. The two inclined slurry injection passages intersect each other to form a set, and multiple sets of the composite ground support 6 are installed at intervals. After slurry injection into all the inclined passages is completed, a secondary reinforcing slurry is injected at the intersections of the slurry injection passages, and the secondary slurry injection areas at the intersections of adjacent slurry injection passages interlock and overlap to ensure that the reinforcement body formed by the secondary slurry injections at the intersections of adjacent slurry injection passages interlock and overlap is generally horizontal.

[0041] This method can reinforce and raise the deep settlement of independent foundations and strip foundations. Compared to ordinary composite piles, the force transmission of the composite ground support 6 is more uniform, allowing the upper load to be transmitted evenly to deeper soil layers. After slurry injection into the inclined passage is completed, a secondary reinforcing slurry injection is performed at the intersection of the slurry injection passage, ensuring stable force transmission at the intersection. This achieves the requirement of permanently stabilizing settlement for the equipment foundation 3, while also achieving the purpose of correcting displacement of the equipment foundation 3.

[0042] The examples of the specific embodiments are all preferred embodiments of the present application and do not limit the scope of protection of the present application, and therefore any equivalent changes made based on the structure, shape and principle of the present application should be included in the scope of protection of the present application. [Explanation of symbols]

[0043] 1...ground, 2...slurry injection pipe, 3...foundation, 4...support layer, 5...soft base layer, 6...composite ground support.

Claims

1. A method for lifting and restoring a subsidence of a deep plant equipment foundation, comprising: The compression modulus ratio between the support layer (4) and the soft base layer (5), i.e., E Ｓ１ / E Ｓ２ S1 determining a ground pressure diffusion angle based on the values ​​of Z / b; S2 determines the load diffusion range based on the ground pressure diffusion angle; Based on the load diffusion range, the unstable soil body in the soft base layer (5) is reinforced by slurry injection to form a slurry injection reinforcement body (S3); S4: Reinforce the support layer (4) by injecting slurry according to the load diffusion range, and arrange slurry injection holes distributed on both sides of the equipment foundation (3) along the two triangular areas of the direction line of the stress diffusion angle; S5: Reinforcement by injecting slurry into the middle of the support layer (4) and lifting it up; and (S6) creating an irregular composite ground support (6) at the bottom of the soft base (5).

2. The method for lifting and restoring the foundation of deep-seated plant equipment according to claim 1, characterized in that the composite ground support (6) in step S6 is a combination of two inclined slurry injection passages, and there is an intersection between the two inclined slurry injection passages.

3. The method for lifting and restoring the foundation of a deep plant facility according to claim 2, characterized in that a plurality of sets of the composite ground supports (6) are installed at intervals.

4. 4. The method for lifting and restoring the foundation of a deep-seated plant equipment according to claim 3, wherein in step S6, after completion of slurry injection into all inclined passages, a secondary reinforcing slurry is injected into the intersections of the slurry injection passages.

5. The method for lifting and restoring the foundation of deep-seated plant equipment according to claim 4, characterized in that in step S6, secondary reinforcing slurry injection is carried out at the intersections of all slurry injection passages, and the secondary slurry injection ranges at the intersections of adjacent slurry injection passages are interlocked and overlap each other.

6. The method for lifting and restoring the foundation of deep-seated plant equipment as described in claim 1, characterized in that in step S4, a retreat-type slurry injection process integrated with excavation and injection is adopted, and each time the excavation is lifted, the excavation is retreated one stage and the slurry is injected one stage.

7. 6. The method for lifting and restoring a subsidence of a deep plant equipment foundation as claimed in claim 5, wherein the reinforcement formed by the secondary slurry injections at the intersections of adjacent slurry injection passages interlocking and overlapping with each other is generally in a horizontal state.

8. 2. The method for lifting and restoring deep plant equipment foundation subsidence as claimed in claim 1, wherein Z / b in step S1 can be used with a difference value between 0.25 and 0.

5.

9. 2. The method for lifting and restoring the foundation of deep-seated plant equipment according to claim 1, wherein in step S4, adjacent slurry injection holes are spaced apart.

10. 2. The method for lifting and restoring the foundation of a deep-seated plant equipment according to claim 1, characterized in that the vertical projection of the slurry injection reinforcement formed in the supporting layer (4) is completely located on the slurry injection reinforcement formed in the soft base layer (5).

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