Compacting grouting foundation structure

Abstract

The utility model discloses a compaction grouting foundation structure in the technical field of civil engineering. The compaction grouting foundation structure comprises a subbase layer, and the subbase layer comprises a grouting target area and a precast pile area arranged around the grouting target area; a grouting pipe is arranged in the grouting targeted area, and compaction grout is injected into the grouting targeted area through the grouting pipe; a precast pile is arranged in the precast pile area, and the precast pile is filled with soil in the circumferential direction. According to the compaction grouting device, grout can be effectively prevented from being diffused to the periphery from the grouting target area in the compaction grouting process, the foundation bearing capacity and the compaction grouting effect are improved, and the grouting cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of civil engineering technology, and in particular to a compaction grouting foundation structure. Background Technology

[0002] When constructing buildings on silty clay soil, compaction grouting is generally used to reinforce the foundation. However, when compaction grouting is performed on loose soil with a high water table, the grout can easily leak out of the foundation through soil cracks or groundwater, resulting in low foundation strength, water pollution, and increased grouting costs.

[0003] To address the technical problem of grout leakage, Chinese invention patent CN116696397A discloses a method for preventing grout leakage through pre-grouting in steeply inclined formations based on freezing. This method involves setting a freezing curtain line outside the grouting curtain target area, arranging vertical or inclined freezing holes along the freezing curtain line, and then injecting water into the freezing holes to form a frozen grout leakage prevention curtain. This prevents grout from overflowing to the ground, effectively filling and sealing formation fractures. However, this method of setting a water-freezing curtain relies on natural low-temperature environments or artificial phase change refrigeration to freeze the curtain, which is difficult to implement and the freezing effect is hard to guarantee. Furthermore, the freezing process lowers the formation temperature, and even with countermeasures, it still affects the formation strength.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a compaction grouting foundation structure to solve the technical problem of insufficient foundation reinforcement effect caused by the diffusion of grout from the grouting target area to the periphery during the compaction grouting process.

[0006] To solve the above-mentioned technical problems, this utility model is implemented using the following technical solution:

[0007] A compaction grouting foundation structure includes a subbase, the subbase including a grouting target area and a precast pile area surrounding the grouting target area; the grouting target area is provided with a grouting pipe, and compaction grout is injected into the grouting target area through the grouting pipe; the precast pile area is provided with precast piles, and the precast piles are circumferentially filled with soil.

[0008] Furthermore, the grouting pipe includes a vertical grouting pipe and an inclined grouting pipe, which are arranged at intervals.

[0009] Furthermore, the inclined grouting pipe gradually moves away from the precast pile area from top to bottom.

[0010] Furthermore, the top of the grouting pipe is provided with a sealing structure.

[0011] Furthermore, the precast piles are vertically arranged in the precast pile area, and the design elevation of the precast piles is lower than the lowest point of the grouting target area.

[0012] Furthermore, the precast pile can be any one of a wooden pile, a concrete square pile, a prestressed concrete pipe pile, or a steel pile.

[0013] Furthermore, a foundation pad layer is laid on the subbase, a foundation layer is laid on the foundation pad layer, and backfill soil is laid on top of the foundation layer.

[0014] Furthermore, the base layer has a phased structure that is larger at the bottom and smaller at the top.

[0015] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0016] This invention provides a compaction grouting foundation structure. A precast pile zone is set around the grouting target area. Compaction grout is injected into the grouting target area through grouting pipes. After construction, the grouting pipes are left in the grouting target area, forming a sealing barrier with the precast piles and surrounding soil. This increases the diffusion resistance of the grout in the medium, effectively preventing the grout from diffusing from the grouting target area to the periphery during compaction grouting, thus improving the compaction grouting effect and the foundation bearing capacity. Compared to setting up a water-freezing anti-grouting curtain, the construction operation of the grouting pipes and precast piles is simpler and easier to implement, reducing grouting construction costs. The compaction grouting foundation structure provided by this invention is suitable for silty clay strata, not only without affecting the strength of the strata but also effectively reinforcing the foundation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a compaction grouting foundation structure provided in an embodiment of this utility model;

[0019] Figure 2 This is a schematic diagram of the structure of a subbase provided in an embodiment of this utility model;

[0020] Figure 3This is a construction process diagram of a subbase provided in an embodiment of this utility model.

[0021] In the diagram: 1-subbase; 2-foundation cushion; 3-foundation layer; 4-backfill soil; 5-grouting target area; 6-precast pile area; 7-precast pile; 8-vertical grouting pipe; 9-inclined grouting pipe. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Example 1

[0023] refer to Figure 1 This utility model embodiment provides a compaction grouting foundation structure, including a subbase 1 located at the bottom of the foundation pit and providing support. For example... Figure 2 As shown, the subbase 1 includes a precast pile area 6 and a grouting target area 5. The precast pile area 6 is arranged around the grouting target area 5, which can increase the resistance to the outward diffusion of grout in the grouting target area 5.

[0024] See also Figure 1 and Figure 2 Precast piles 7 are installed in the precast pile area 6, and the precast piles 7 are surrounded by soil. As one embodiment, multiple precast piles 7 can be installed, evenly distributed in a ring within the precast pile area 6. The number, material, spacing, and depth of the precast piles 7 can be determined in advance according to actual project needs. During construction, the precast piles 7 can be inserted into the precast pile area 6 by pile driving or pile pressing. The precast piles 7, as a single structure, can be prefabricated using wooden piles, concrete square piles, prestressed concrete pipe piles, or steel piles. Compared to silty clay soil layers, they have higher density. Multiple precast piles 7 form a fence-like sealing barrier within the precast pile area 6. To achieve a better sealing effect in the precast pile area 6, after the precast piles 7 are installed, the soil surrounding the precast piles 7 should be further compacted to expel air and moisture between soil particles, increase soil density, and ensure that the soil around the precast piles 7 also has high resistance to prevent grout diffusion.

[0025] Grouting target zone 5 is the core area of ​​the subbase 1 that provides bearing capacity for the upper load, and it is the target area for compaction grouting. For example... Figure 1As shown, a grouting pipe is installed in the grouting target area 5. During the compaction grouting process, the construction personnel inject grout into the grouting target area 5 through the grouting pipe. During the grouting process, the grout gradually discharges the moisture and air from the soil particles and forms grout bubbles in the grouting target area 5. The grout bubbles will gradually increase the pressure on the surrounding soil, eventually forming a "grout-soil" composite, thereby achieving the purpose of improving the soil strength and bearing capacity of the grouting target area 5.

[0026] During construction, the grouting pipe can be gradually raised upwards as the grout is injected until compaction grouting is completed. After compaction grouting is completed, the grouting pipe exposed above the grouting target area 5 can be cut off, and the remaining part of the grouting pipe is left in the grouting target area 5. At this time, the grouting pipe, together with the precast pile area 6 (including the precast pile 7 and the surrounding soil of the precast pile 7), can form a sealing barrier to prevent the grout from spreading to the outside of the grouting target area 5, thereby further improving the technical effect of preventing grout leakage; on the other hand, the left-in grouting pipe can also increase the strength of the soil in the grouting target area 5, playing a role in reinforcing the foundation.

[0027] It should be noted that, to achieve better grout leakage prevention, multiple grouting pipes can be installed, evenly distributed and positioned close to the precast pile area 6. This arrangement not only increases the grout diffusion resistance at the edge of the grouting target area 5 and prevents grout leakage, but also facilitates the uniform and rapid diffusion of grout within the grouting target area 5, thereby improving the compaction grouting efficiency.

[0028] In some embodiments, the grouting pipe may include a plurality of vertical grouting pipes 8 and a plurality of inclined grouting pipes 9, which may be spaced apart from each other. Clearly, the vertical grouting pipes 8 provide vertical compaction grouting to the grouting target area 5. As the grout is gradually injected, the vertical grouting pipes 8 gradually rise upwards, thereby achieving uniform and rapid grouting of the grouting target area 5 in the vertical direction. The inclination angle of the inclined grouting pipes 9 is as follows: Figure 1 As shown, the grouting pipe 9 gradually moves away from the precast pile area 6 from top to bottom, and its bottom end can extend to the bottom of the upper load. The inclined grouting pipe 9 can bear the upper load to a certain extent, helping the "grout-soil" composite located at the bottom of the upper load to share part of the load, thus having the effect of reinforcing the foundation.

[0029] To prevent grout from bypassing the precast pile 7 and leaking out from the bottom of the grouting target area 5, in this embodiment, the design elevation of the precast pile 7 is lower than the lowest point of the grouting target area 5. During compaction grouting, the lower ends of the vertical grouting pipe 8 and the inclined grouting pipe 9 are also not higher than the design elevation of the precast pile 7. Optionally, the design elevation of the precast pile 7 can be 0.5m lower than the lowest point of the grouting target area 5.

[0030] In a civil construction site, the construction process for building the subbase 1 provided in this embodiment of the invention is as follows: Figure 3 As shown:

[0031] Step 1: Clean up the site;

[0032] Step 2: Determine the number, depth, and spacing of precast piles 7 based on the construction area, and arrange the precast pile holes along a straight line;

[0033] Step 3: Based on the determined construction parameters, perform pile driving or pile pressing. Sequentially insert all precast piles 7 into the design elevation by pile driving or pile pressing. The design elevation of precast piles 7 must be 0.5m lower than the lowest point of grouting. During the pile driving or pile pressing process, the precast piles 7 can compact the surrounding soil by squeezing to increase the soil density, thereby preventing grout leakage during the subsequent grouting process.

[0034] Step 4: Compact the soil between and around several precast piles 7 to complete the construction of the precast pile area 6;

[0035] Step 5: Determine the number, depth, and spacing of grouting holes based on the construction area, and arrange vertical grouting pipes 8 and inclined grouting pipes 9 in a staggered manner along a straight line;

[0036] Step 6: Perform vertical compaction grouting according to the planned grouting hole depth, grouting pressure and other parameters. After completing grouting to a certain depth, raise the vertical grouting pipe 8 and continue grouting. Finally, seal the vertical grouting pipe 8.

[0037] Step 7: Continue grouting the next vertical grouting pipe 8 until all vertical grouting is completed;

[0038] Step 8: Perform oblique grouting according to the planned grouting hole depth, grouting pressure and other parameters. After completing grouting to a certain depth, raise the inclined grouting pipe 9 and continue grouting. Finally, seal the inclined grouting pipe 9.

[0039] Step 9: Continue grouting through the next inclined grouting pipe 9 until all inclined grouting is completed;

[0040] Step 10: Cut all exposed grouting pipes to complete the subbase 1 of the compacted grouting foundation structure.

[0041] To prevent grout from leaking out of the top opening of the grouting pipe, the top opening of the grouting pipe located in the grouting target area 5 can be sealed.

[0042] It should be understood that the description of the state and arrangement of the grouting pipes and the material and arrangement of the precast piles 7 in this embodiment is to more clearly illustrate the technical solution of this utility model. In the actual construction process, the grouting pipes can also be set in a vertical state or in an inclined state. The material of the precast piles 7 is not limited to the material provided in this utility model embodiment. Other materials that can achieve the same effect can also be selected according to the actual project. The arrangement of the grouting pipes and the precast piles 7 can also be set to unequal spacing, irregularity or according to the actual project needs such as the setting position and shape of the foundation pit, so as to meet the actual construction needs. Example 2

[0043] This embodiment provides a compaction grouting foundation structure, including a subbase 1 as described in Embodiment 1. In this embodiment, a foundation pad 2 is further laid above the subbase 1 to facilitate foundation concrete construction and bear foundation loads. A foundation layer 3 is set on top of the foundation pad 2, and backfill soil 4 is covered on the foundation layer 3. The foundation layer 3 is designed with a structure that is smaller at the top and larger at the bottom. More specifically, the foundation layer 3 can be designed as a stepped structure that is smaller at the top and larger at the bottom, so as to minimize the pressure exerted by the foundation layer 3 on the subbase 1 under the same foundation load. The foundation load borne by the foundation layer 3 should avoid directly acting on the grouting pipe and the precast pile area 6. Therefore, the foundation layer 3 should be concentrated as much as possible in the middle of the grouting target area 5. The foundation layer 3 can be designed as an annular stepped shape. To ensure that the subbase 1 is subjected to more uniform stress, the foundation layer 3 can be coaxially arranged with the grouting target area 5.

[0044] In the description of this utility model, it should be understood that the terms "center," "vertical," "inclined," "upper," "lower," "front," "rear," "left," "right," "inner," "outer," "top," and "bottom," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only used to explain the relative positional relationships and movement between the structures in a specific posture. If the specific posture changes, the directional indication will also change accordingly. These terms are used only for the convenience of describing this utility model and for simplifying the description, and are not intended to indicate or imply that the structure referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0045] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A compaction grouting foundation structure, comprising a subbase (1), characterized in that, The subbase (1) includes a grouting target area (5) and a precast pile area (6) surrounding the grouting target area (5). The grouting target area (5) is provided with a grouting pipe, and the grouting target area (5) is injected with compaction grout through the grouting pipe; The precast pile area (6) is provided with precast piles (7), and the precast piles (7) are filled with soil around their perimeter.

2. The compaction grouting foundation structure according to claim 1, characterized in that, The grouting pipe includes a vertical grouting pipe (8) and an inclined grouting pipe (9), which are spaced apart from each other.

3. The compaction grouting foundation structure according to claim 2, characterized in that, The inclined grouting pipe (9) gradually moves away from the precast pile area (6) from top to bottom.

4. The compaction grouting foundation structure according to claim 1, characterized in that, The top of the grouting pipe is equipped with a sealing structure.

5. The compaction grouting foundation structure according to claim 1, characterized in that, The precast pile (7) is vertically set in the precast pile area (6), and the design elevation of the precast pile (7) is lower than the lowest point of the grouting target area (5).

6. The compaction grouting foundation structure according to claim 1, characterized in that, The precast pile (7) is any one of the following: wooden pile, concrete square pile, prestressed concrete pipe pile, and steel pile.

7. The compaction grouting foundation structure according to any one of claims 1 to 6, characterized in that, A foundation cushion layer (2) is laid on the base layer (1), a foundation layer (3) is laid on the foundation cushion layer (2), and backfill soil (4) is covered on the foundation layer (3).

8. The compaction grouting foundation structure according to claim 7, characterized in that, The base layer (3) is a stage-shaped structure with a larger bottom and a smaller top.

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