Layered annular dense hole post-grouting construction structure of anti-pulling and anti-pressure cast-in-place pile

Abstract

This invention relates to the technical field of cast-in-place piles and discloses a layered annular dense-hole post-grouting construction structure for tension and compression cast-in-place piles. The structure includes a pile body formed in a pile hole, with pile side soil on the outside of the pile body, a reinforcing cage inside the pile body, and a pile bottom grouting pipe and pile side grouting pipes on the reinforcing cage. The bottom of the pile bottom grouting pipe is higher than the bottom of the reinforcing cage and has multiple bottom grouting ports. The bottoms of the multiple pile side grouting pipes are arranged sequentially and alternately along the axial direction of the reinforcing cage, and the bottoms of the pile side grouting pipes are respectively connected to an annular grouting pipe. The annular grouting pipes are arranged around the circumference of the reinforcing cage and have multiple layered grouting ports. The outer periphery of the pile body has multiple layered grout layers formed by grouting through the pile side grouting pipes. These layered grout layers surround the outer periphery of the pile body and penetrate into the pile side soil. The bottom of the pile body has a pile bottom grout layer formed by grouting through the pile bottom grouting pipes, which penetrates into the bearing stratum.

Description

Technical Field

[0001] This invention patent relates to the technical field of cast-in-place piles, and more specifically, to a grouting construction structure for layered annular dense holes in anti-tension and anti-compression cast-in-place piles. Background Technology

[0002] The bearing capacity of tension-compression cast-in-place piles mainly consists of the skin friction acting on the pile side and the bearing capacity at the pile bottom. The main factors affecting the bearing capacity of tension-compression piles typically include pile formation technology, soil conditions, and the thickness of sediment at the bottom of the borehole. Currently, because mud slurry is often used for borehole construction, a thick layer of mud cake forms on the borehole wall, which significantly negatively impacts the skin friction on the pile side. Furthermore, incomplete borehole cleaning and excessive sediment thickness directly affect the bearing capacity at the pile bottom, making it difficult for tension-compression cast-in-place piles to meet the design bearing capacity requirements.

[0003] In existing technologies, post-pile grouting is generally used to improve the bearing capacity of single piles in cast-in-place piles that are both tensile and compressive. Post-pile grouting involves grouting the pile's reinforcing cage in layers at certain intervals, with at least two grouting risers installed in each layer to ensure uniform grouting. Each riser has a spray hole at its bottom. However, this method results in a large number of grouting risers per layer, a significant workload in installing them on the reinforcing cage, and a major challenge in connecting the numerous risers during the sectional hoisting of the reinforcing cage. Furthermore, the limited number of spray holes, with only a spray hole at the end of each riser, leads to uneven grout distribution, affecting the grouting effect. Summary of the Invention

[0004] The purpose of this invention is to provide a grouting construction structure for layered annular dense holes in cast-in-place piles with tensile and compressive strength, which aims to solve the problem that the existing construction method for improving the single pile bearing capacity of cast-in-place piles with tensile and compressive strength through post-pile grouting is relatively cumbersome and the grouting effect cannot be guaranteed.

[0005] The present invention is implemented as follows: a layered annular dense hole post-grouting construction structure for tension and compression grouting piles includes a pile body formed in the pile hole, a pile side soil body on the outside of the pile body, a bearing layer below the pile body, and a sedimentation zone at the bottom of the pile body, wherein a sedimentation layer is deposited in the sedimentation zone.

[0006] The pile body has a steel cage, which includes multiple main bars arranged in a ring and stirrups. The multiple main bars form a cage area, and the stirrups are wrapped around the outer perimeter of the cage area and are respectively connected to the multiple main bars.

[0007] The reinforcing cage is equipped with a pile bottom grouting pipe and multiple pile side grouting pipes. The pile bottom grouting pipe and the pile side grouting pipe are respectively arranged to extend along the axial direction of the reinforcing cage. The bottom of the pile bottom grouting pipe is higher than the bottom of the reinforcing cage. The pile bottom grouting pipe is equipped with multiple bottom grouting ports.

[0008] The bottoms of multiple pile-side grouting pipes are arranged sequentially and spaced up and down along the axial direction of the reinforcing cage. The bottoms of the multiple pile-side grouting pipes are respectively connected to annular grouting pipes. The annular grouting pipes are arranged around the circumference of the reinforcing cage and are provided with multiple layered grouting ports.

[0009] The outer periphery of the pile body has multiple layered grout layers formed by grouting through pile side grouting pipes. The layered grout layers surround the outer periphery of the pile body and penetrate into the soil around the pile. The bottom of the pile body has a pile bottom grout layer formed by grouting through pile bottom grouting pipes. The pile bottom grout layer penetrates into the bearing layer.

[0010] Optionally, multiple layers of grout are arranged sequentially along the circumference of the pile.

[0011] Optionally, the adjacent layers of the slurry are arranged in an overlapping manner.

[0012] Optionally, the soil around the pile may have cracks caused by grouting during the grouting process, and the layered grout layer may penetrate and fill the cracks.

[0013] Optionally, the sediment layer has pile bottom gaps that are broken by grout during the grouting process, and the pile bottom grout layer penetrates and fills the pile bottom gaps.

[0014] Optionally, the pile bottom grout layer overlaps with the adjacent layered grout layer.

[0015] Optionally, the pile bottom grout layer expands outward from the bottom of the pile body to the outer periphery of the pile body, and the diameter of the pile bottom grout layer is larger than the diameter of the pile body.

[0016] Optionally, the pile-side grouting pipe is arranged inside the reinforcing cage, and the annular grouting pipe surrounds the outside of the reinforcing cage; the bottom of the pile-side grouting pipe is connected to a tee, the tee has two tee outlets, and the two ends of the annular grouting pipe are respectively connected to the two tee outlets; a plurality of layered grouting ports are arranged at intervals along the circumference of the annular grouting pipe and are arranged on the outside of the annular grouting pipe.

[0017] Optionally, the bottom of the pile bottom grouting pipe is arranged in a closed manner to form a closed end, and a plurality of bottom grouting ports are arranged on the side wall of the pile bottom grouting pipe. The plurality of bottom grouting ports are arranged at intervals along the circumference of the pile bottom grouting pipe and are staggered along the axial direction of the bottom grouting pipe.

[0018] Optionally, the lower part of the pile bottom grouting pipe has a shotcrete section, a plurality of bottom grouting ports are formed on the shotcrete section, and the closed end is formed at the bottom of the shotcrete section;

[0019] The shotcrete section is provided with a horizontally rotating cylinder that is coaxially arranged with the grouting pipe at the bottom of the pile. The rotating cylinder has a rotating cavity with a top opening and a closed bottom. The top of the rotating cylinder is provided with a plurality of horizontally arranged partitions, which surround the outer periphery of the top opening and are spaced apart along the circumference of the top opening.

[0020] There is an annular region between the outer wall of the rotating head and the inner wall of the spraying section. The annular region is arranged around the outer periphery of the rotating cylinder. There is a hollow region between adjacent partitions. The hollow region is connected to the annular region from top to bottom. The rotating cylinder is provided with multiple connecting holes. The multiple connecting holes are arranged at intervals along the circumference of the rotating cylinder and are staggered along the axial direction of the rotating cylinder.

[0021] During the grouting process of the pile bottom grouting pipe, the grout in the rotating cavity enters the annular area through multiple connecting holes, the grout above the partition enters the annular area through the hollow area, and the grout in the annular area is sprayed outward through multiple bottom grouting ports.

[0022] The rotating cylinder is subjected to pressure from the slurry passing through the hollowed-out area and the slurry passing through the connecting hole, causing it to rotate on its own to balance the circumferential pressure of the slurry in the annular area.

[0023] Compared with existing technologies ， The present invention provides a layered annular dense hole post-grouting construction structure for anti-tension and anti-compression cast-in-place piles. By setting a pile bottom grouting pipe and a pile side grouting pipe on the reinforcing cage, and connecting the bottom of the pile side grouting pipe to an annular grouting pipe, the annular grouting pipe is arranged around the outer perimeter of the reinforcing cage. In this way, after the concrete is poured and the pile is left to stand for a set time to form a pile, post-grouting is performed through the pile side grouting pipe and the pile bottom grouting pipe. The grout plays a role in penetrating, filling, compacting, splitting and consolidating the bearing layer at the pile end, the sediment layer, the soil on the pile side and the mud skin around the pile, thereby improving the bearing capacity of a single pile.

[0024] In this process, grout is injected into the pile hole sequentially through multiple pile-side grouting pipes from top to bottom. The grout is then sprayed outward from the layered grouting ports on the annular grouting pipe. Within each set interval, only one pile-side grouting pipe and one annular grouting pipe are needed to perform post-pile grouting for that single layer. At the same time, the arrangement of multiple layered grouting ports on the annular grouting pipe ensures that the grout can be sprayed evenly towards the soil around the pile side of the reinforcing cage. This method is convenient, fast, and effectively improves construction efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the layered annular dense hole post-grouting construction structure for the pull-out and compression-resistant cast-in-place pile provided by the present invention;

[0026] Figure 2 This is a schematic diagram of the connection between the pile-side grouting pipe and the annular grouting pipe provided by the present invention;

[0027] Figure 3 This is a front view schematic diagram of the pile bottom grouting pipe provided by the present invention;

[0028] Figure 4 This is a schematic diagram of the unfolded pile bottom grouting pipe provided by the present invention;

[0029] Figure 5 This is a partial schematic diagram of the shotcrete section provided by the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0032] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0033] Reference Figure 1-5 The image shows a preferred embodiment of the present invention.

[0034] The present invention provides a layered annular dense hole post-grouting construction structure for anti-pull-out and anti-compression cast-in-place piles, including a pile body formed in the pile hole, a pile side soil body on the outside of the pile body, a bearing layer below the pile body, and a sedimentation zone at the bottom of the pile body, wherein a sedimentation layer is deposited in the sedimentation zone.

[0035] The pile contains a steel cage, which includes multiple main bars arranged in a ring and stirrups. The multiple main bars form a cage area, and the stirrups are wrapped around the outer perimeter of the cage area and connected to the multiple main bars respectively.

[0036] The reinforcing cage is equipped with a bottom grouting pipe 200 and multiple side grouting pipes 100. The bottom grouting pipe 200 and the side grouting pipes 100 extend along the axial direction of the reinforcing cage, respectively. The bottom of the bottom grouting pipe 200 is higher than the bottom of the reinforcing cage, and multiple bottom grouting ports 201 are provided on the bottom grouting pipe 200.

[0037] The bottom of multiple pile-side grouting pipes 100 are arranged sequentially and alternately along the axial direction of the reinforcing cage. The bottom of the multiple pile-side grouting pipes 100 is connected to an annular grouting pipe 110. The annular grouting pipe 110 is arranged around the circumference of the reinforcing cage. The annular grouting pipe 110 is provided with multiple layered grouting ports.

[0038] The outer periphery of the pile body has multiple layered grout layers 10 formed by grouting through the pile side grouting pipe 100. The layered grout layers 10 surround the outer periphery of the pile body and penetrate into the soil on the pile side. The bottom of the pile body has a pile bottom grout layer 20 formed by grouting through the pile bottom grouting pipe 200. The pile bottom grout layer 20 penetrates into the bearing layer.

[0039] The above-mentioned layered annular dense hole post-grouting construction structure for tension and compression cast-in-place piles uses a pile bottom grouting pipe 200 and a pile side grouting pipe 100 on the reinforcing cage. The bottom of the pile side grouting pipe 100 is connected to an annular grouting pipe 110, which is arranged around the outer periphery of the reinforcing cage. In this way, after the concrete is poured and the pile is left to stand for a set time to form a pile, post-grouting is performed through the pile side grouting pipe 100 and the pile bottom grouting pipe 200. The grout plays a role in penetrating, filling, compacting, splitting, and consolidating the bearing layer at the pile end, the sediment layer, the soil on the pile side, and the mud skin around the pile, thereby improving the bearing capacity of a single pile.

[0040] In this process, grout is injected into the pile hole sequentially through multiple pile-side grouting pipes 100 from top to bottom. The grout is then sprayed outward from the layered grouting ports on the annular grouting pipe 110 through the pile-side grouting pipes 100. Within each set interval, only one pile-side grouting pipe 100 and one annular grouting pipe 110 are needed to perform post-pile grouting for a single layer. At the same time, the arrangement of multiple layered grouting ports on the annular grouting pipe 110 ensures that the grout can be sprayed evenly towards the pile-side soil around the reinforcing cage, making construction convenient, fast, and effectively improving construction efficiency.

[0041] Multiple layered grouting layers 10 are arranged sequentially along the circumference of the pile. In this way, multiple layered grouting layers 10 are formed by grouting through multiple annular injection pipes 110. The multiple layered grouting layers 10 play a role in penetrating, filling, compacting, splitting and consolidating the mud skin on the outer periphery of the pile, thereby achieving the effect of improving the bearing capacity of a single pile.

[0042] The adjacent layers of grout 10 are arranged in an overlapping manner. This ensures that the grout is fully mixed into the soil around the pile.

[0043] During the grouting process, the soil around the pile is fractured, creating gaps along the pile side. Layered grout layer 10 then seeps in and fills these gaps. This process serves to penetrate, fill, compact, split, and consolidate the soil.

[0044] The sediment layer contains pile bottom gaps that are broken by the grout during the grouting process, and the pile bottom grout layer 20 penetrates and fills these gaps. In this way, the grout first splits and penetrates in the sediment area at the pile bottom, and then continues to penetrate into the bearing layer at the pile bottom, making the sediment and the soil near the pile bottom dense, producing a "base expansion" effect, thereby improving the end bearing capacity.

[0045] The bottom grout layer 20 overlaps with the adjacent layered grout layer 10. This ensures that the grout is fully mixed into the soil surrounding the pile.

[0046] Specifically, the pile bottom grout layer 20 expands outward from the bottom of the pile body and extends to the outer periphery of the pile body, and the diameter of the pile bottom grout layer 20 is larger than the diameter of the pile body.

[0047] The pile-side grouting pipe 100 is arranged inside the reinforcing cage, and the annular grouting pipe 110 surrounds the outside of the reinforcing cage. The bottom of the pile-side grouting pipe 100 is connected to a tee head 120, which has two tee outlets. The two ends of the annular grouting pipe 110 are respectively connected to the two tee outlets. Multiple layered grouting ports are arranged at intervals along the circumference of the annular grouting pipe 110 and are located on the outside of the annular grouting pipe 110. In this way, the tee head 120 changes the direction of grout delivery from the vertical direction to the horizontal annular direction, realizing the connection between the pile-side grouting pipe 100 and the annular grouting pipe 110. The pile-side grouting pipe 100 is connected to the tee head 120 through a right-angle elbow.

[0048] The bottom of the pile bottom grouting pipe 200 is arranged in a closed manner, forming a closed end 202. Multiple bottom grouting ports 201 are arranged on the side wall of the pile bottom grouting pipe 200, and the multiple bottom grouting ports 201 are arranged at intervals along the circumference of the pile bottom grouting pipe 200, and are staggered along the axial direction of the bottom grouting pipe. In this way, when the grout reaches the closed end 202, the grout is sprayed outward from the bottom grouting ports 201 from bottom to top.

[0049] In this embodiment, the lower part of the pile bottom grouting pipe 200 has a sprayed section, a plurality of bottom grouting ports 201 are formed on the sprayed section, and a closed end 202 is formed at the bottom of the sprayed section;

[0050] The shotcrete section is provided with a horizontally rotating cylinder 210 that is coaxially arranged with the pile bottom grouting pipe 200. The rotating cylinder 210 has a rotating cavity with a top opening and the bottom of the rotating cavity is closed. The top of the rotating cylinder 210 is provided with multiple horizontally arranged partitions 212, which surround the outer periphery of the top opening and are spaced apart along the circumference of the top opening.

[0051] There is an annular region between the outer wall of the rotating head and the inner wall of the shotcrete section. The annular region is arranged around the outer periphery of the rotating cylinder 210. There is a hollow region between adjacent partitions 212. The hollow region is connected to the annular region from top to bottom. The rotating cylinder 210 is provided with multiple connecting holes 211. The multiple connecting holes 211 are arranged at intervals along the circumference of the rotating cylinder 210 and are staggered along the axial direction of the rotating cylinder 210.

[0052] During the grouting process of the pile bottom grouting pipe 200, the grout in the rotating cavity enters the annular area through multiple connecting holes 211, the grout above the partition 212 enters the annular area through the hollow area, and the grout in the annular area is sprayed outward through multiple bottom grouting ports 201.

[0053] The rotating cylinder 210 is subjected to pressure from the slurry passing through the hollowed-out area and the slurry passing through the connecting hole 211, causing it to rotate on its own to balance the circumferential pressure of the slurry in the annular area. In this way, as the rotating cylinder 210 rotates, the slurry is evenly sprayed outward through the bottom injection port 201.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A layered annular dense-hole post-grouting construction structure for tension and compression grouting piles, characterized in that, It includes a pile body formed in a pile hole, a pile side soil body on the outside of the pile body, a bearing layer below the pile body, and a sedimentation zone at the bottom of the pile body, wherein a sedimentation layer is deposited in the sedimentation zone; The pile body has a steel cage, which includes multiple main bars arranged in a ring and stirrups. The multiple main bars form a cage area, and the stirrups are wrapped around the outer perimeter of the cage area and are respectively connected to the multiple main bars. The reinforcing cage is equipped with a pile bottom grouting pipe and multiple pile side grouting pipes. The pile bottom grouting pipe and the pile side grouting pipe are respectively arranged to extend along the axial direction of the reinforcing cage. The bottom of the pile bottom grouting pipe is higher than the bottom of the reinforcing cage. The pile bottom grouting pipe is equipped with multiple bottom grouting ports. The bottoms of multiple pile-side grouting pipes are arranged sequentially and spaced up and down along the axial direction of the reinforcing cage. The bottoms of the multiple pile-side grouting pipes are respectively connected to annular grouting pipes. The annular grouting pipes are arranged around the circumference of the reinforcing cage and are provided with multiple layered grouting ports. The outer periphery of the pile body has multiple layered grout layers formed by grouting through pile side grouting pipes. The layered grout layers surround the outer periphery of the pile body and penetrate into the soil around the pile. The bottom of the pile body has a pile bottom grout layer formed by grouting through pile bottom grouting pipes. The pile bottom grout layer penetrates into the bearing layer. The bottom of the pile bottom grouting pipe is arranged in a closed manner to form a closed end. Multiple bottom grouting ports are arranged on the side wall of the pile bottom grouting pipe. The multiple bottom grouting ports are arranged at intervals along the circumference of the pile bottom grouting pipe and are staggered along the axial direction of the bottom grouting pipe. The lower part of the pile bottom grouting pipe has a sprayed section, a plurality of bottom grouting ports are formed on the sprayed section, and the closed end is formed at the bottom of the sprayed section; The shotcrete section is provided with a horizontally rotating cylinder that is coaxially arranged with the grouting pipe at the bottom of the pile. The rotating cylinder has a rotating cavity with a top opening and a closed bottom. The top of the rotating cylinder is provided with a plurality of horizontally arranged partitions, which surround the outer periphery of the top opening and are spaced apart along the circumference of the top opening. There is an annular region between the outer wall of the rotating cylinder and the inner wall of the shotcrete section. The annular region is arranged around the outer periphery of the rotating cylinder. There is a hollow region between adjacent partitions. The hollow region is connected to the annular region from top to bottom. The rotating cylinder is provided with multiple connecting holes. The multiple connecting holes are arranged at intervals along the circumference of the rotating cylinder and are staggered along the axial direction of the rotating cylinder. During the grouting process of the pile bottom grouting pipe, the grout in the rotating cavity enters the annular area through multiple connecting holes, the grout above the partition enters the annular area through the hollow area, and the grout in the annular area is sprayed outward through multiple bottom grouting ports. The rotating cylinder is subjected to pressure from the slurry passing through the hollowed-out area and the slurry passing through the connecting hole, causing it to rotate on its own to balance the circumferential pressure of the slurry in the annular area.

2. The layered annular dense-hole post-grouting construction structure for anti-tension and anti-compression cast-in-place piles as described in claim 1, characterized in that, Multiple layers of grout are arranged sequentially along the circumference of the pile.

3. The layered annular dense-hole post-grouting construction structure for anti-tension and anti-compression cast-in-place piles as described in claim 1, characterized in that, The adjacent stratified slurry layers are arranged in an overlapping manner.

4. The layered annular dense-hole post-grouting construction structure for anti-tension and anti-compression cast-in-place piles as described in claim 1, characterized in that, The soil around the pile has cracks caused by the grout during the grouting process, and the layered grout layer seeps in and fills the cracks.

5. The layered annular dense-hole post-grouting construction structure for anti-pull-out and anti-compression cast-in-place piles as described in claim 4, characterized in that, The sediment layer contains pile bottom gaps that are broken by grout during the grouting process, and the pile bottom grout layer penetrates and fills the pile bottom gaps.

6. The layered annular dense-hole post-grouting construction structure for anti-tension and anti-compression cast-in-place piles as described in claim 1, characterized in that, The grout layer at the bottom of the pile overlaps with the adjacent layered grout layers.

7. The layered annular dense-hole post-grouting construction structure for anti-tension and anti-compression cast-in-place piles as described in claim 1, characterized in that, The grout layer at the bottom of the pile expands outward from the bottom of the pile body and extends to the outer periphery of the pile body. The diameter of the grout layer at the bottom of the pile is larger than the diameter of the pile body.

8. The layered annular dense-hole post-grouting construction structure for anti-tension and anti-compression cast-in-place piles as described in claim 1, characterized in that, The pile-side grouting pipe is arranged inside the reinforcing cage, and the annular grouting pipe surrounds the outside of the reinforcing cage; the bottom of the pile-side grouting pipe is connected to a tee, the tee has two tee outlets, and the two ends of the annular grouting pipe are respectively connected to the two tee outlets. The plurality of the layered grouting ports are arranged at intervals along the circumference of the annular grouting pipe and are located on the outside of the annular grouting pipe.

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