Basement bottom plate pile repairing structure and method integrated with underground water control

Abstract

The invention provides a basement bottom plate pile repairing structure and method integrating underground water control. The basement bottom plate pile repairing structure comprises MJS reinforcing soil arranged at the pit bottom below a basement bottom plate; the steel casing penetrates through the hole of the basement bottom plate and is inserted into MJS reinforcing soil at the pit bottom below the basement bottom plate, and the steel casing is higher than the basement bottom plate; the annular hoop plate is arranged in the opening of the basement bottom plate and is positioned on the outer side wall of the steel casing; the steel ring plate is arranged in the opening of the basement bottom plate and is positioned on the outer side wall of the annular hoop plate; the vertical stiffening ribs are positioned in the opening of the basement bottom plate and are arranged on the outer side wall of the annular hoop plate at intervals; a groove is welded to the outer side wall, higher than the basement bottom plate, of the steel casing, and the groove is welded to basement bottom plate reinforcing steel bars and reinforcing steel bars around the groove. The pile cap covering the upper portion of the opening of the basement bottom plate can achieve underground water control measures, so that the supplementary pile can be constructed under the condition that extra precipitation construction is not carried out.

Description

Technical Field

[0001] This invention relates to a basement floor slab reinforcement pile structure and method with integrated groundwater control. Background Technology

[0002] In urban renewal projects, due to various factors such as adjustments to building functions, updates to design codes, and accumulation of structural deformation, the bearing capacity of the structural foundation is often redesigned, resulting in frequent situations where additional foundation works are added to the foundation structure.

[0003] Given that the original basement foundation slab has already been formed, the construction of additional engineering piles requires breaking through a portion of the basement foundation slab. In buildings involving deep-buried basements, the groundwater level is often higher than that of the foundation basement slab. Breaking through the basement slab and during the pile-forming process can damage the impermeable layer of the underground soil, causing a sudden surge of groundwater (especially confined water).

[0004] In response to the above situation, the traditional method of adding piles to basement structures includes the necessary dewatering work. The specific construction steps are as follows: in-situ drilling of holes for depressurization and installation of dewatering wells for the addition of piles to the basement floor slab; partial demolition of the basement floor slab for the addition of piles; construction of the addition piles; connection between the basement floor slab and the piles; sealing of the dewatering wells; and anti-seepage and leak-proofing of the basement floor slab.

[0005] The conventional method of adding piles involves a complex construction process. In addition to the holes for adding piles, additional dewatering holes need to be opened in the basement floor slab, which is not conducive to the long-term water seepage prevention effect of the building. Furthermore, secondary dewatering of the existing structure is very likely to cause groundwater and soil erosion and settlement of the surrounding soil, which is not conducive to the protection of surrounding buildings, urban pipelines, underground rail transit, etc.

[0006] Therefore, in the urban renewal sector of the existing urban development market, there is an urgent need to find breakthroughs in the traditional construction techniques for supplementary piles to enhance the resilience of buildings and the surrounding environment. Summary of the Invention

[0007] The purpose of this invention is to provide a basement floor slab reinforcement pile structure and method with integrated groundwater control.

[0008] To address the above problems, this invention provides a basement floor slab re-piling structure with integrated groundwater control, comprising:

[0009] MJS reinforcement soil is installed at the bottom of the pit under the basement floor slab;

[0010] A steel casing is inserted through an opening in the basement floor slab and into the MJS reinforced soil at the bottom of the pit beneath the basement floor slab, with the steel casing extending above the basement floor slab.

[0011] An annular hoop plate is installed in the opening in the basement floor slab and located on the outer wall of the steel casing.

[0012] A steel ring plate is installed in the opening of the basement floor slab and located on the outer wall of the annular hoop plate.

[0013] Vertical stiffening ribs are located in the opening of the basement floor slab and are spaced apart on the outer wall of the annular hoop. The top of each vertical stiffening rib is connected to the bottom wall of the steel ring plate, and the side wall of each vertical stiffening rib is connected to the outer wall of the annular hoop.

[0014] The outer wall of the steel casing that extends above the basement floor slab is welded with a bevel, which is welded to the surrounding basement floor slab reinforcement bars and reinforcing bars.

[0015] A pile cap covering the opening in the basement floor slab.

[0016] Furthermore, in the above structure, annular stirrups are also provided around the steel casing.

[0017] Furthermore, in the above structure, the gap between the steel casing and the basement floor slab and cushion layer is sealed by compaction grouting.

[0018] Furthermore, in the above structure, when a low-headroom pile driver is used for construction, the steel casing extends beyond the basement floor slab.

[0019] Furthermore, in the above structure, when conventional pile drivers are used for construction, the steel casing passes through the basement floor slab, basement floor, basement intermediate floor slab, and basement roof slab sequentially from bottom to top, and extends out of the basement roof slab.

[0020] Furthermore, in the above structure, the openings in the basement floor slab include:

[0021] Pre-holes used for grouting of MJS reinforced soil;

[0022] A primary hole enlargement method used for inserting steel casings during bored pile construction;

[0023] Used for secondary hole enlargement in the construction of welded steel ring plates and pile sealing nodes.

[0024] Furthermore, in the above structure, a grouting pipe is also pre-embedded inside the pile cap, and one end of the grouting pipe is connected to a grouting conduit.

[0025] Furthermore, in the above structure, the steel casing is grouted with micro-expansion concrete; the steel casing is grouted with non-shrink concrete.

[0026] Furthermore, in the above structure, bentonite waterstop strips are installed at the inside corner of the protruding step of the opening in the basement floor slab.

[0027] According to another aspect of the present invention, a method for supplementing piles in a basement floor slab with integrated groundwater control is also provided, employing the aforementioned integrated groundwater control structure for supplementing piles in a basement floor slab, the method comprising:

[0028] Step 1: Based on the center positioning of the supplementary pile, use an Atlas drilling rig to drill pilot holes in the basement floor slab;

[0029] Step 2: At the location of the pilot hole, the soil at the location of the pile foundation to be constructed is reinforced using the MJS soil reinforcement method;

[0030] Step 3: Make an enlarged hole in the basement floor slab, with the diameter of the enlarged hole slightly larger than the diameter of the steel casing to be embedded;

[0031] Step 4: Install a steel casing on the primary borehole, inserting the steel casing below the basement floor slab;

[0032] Step 5: If low-headroom equipment is used for construction inside the basement, concrete is poured to the bottom of the basement floor slab through the low-headroom equipment and short steel casing; if conventional equipment is used, the long steel casing is extended to the ground for construction, and concrete is poured from the ground to the bottom of the basement floor slab through the long steel casing.

[0033] Step 6: Open a secondary enlarged hole in the basement floor slab; the shape of the secondary enlarged hole is a downward convex stepped shape according to the thickness H of the basement floor slab. Within the upper H / 2 range of the thickness H of the basement floor slab, the size of the secondary enlarged hole is 1 meter outside the pre-embedded steel casing; within the lower H / 2 range of the thickness H of the basement floor slab, the size of the enlarged hole is 0.5 meters outside the pre-embedded steel casing.

[0034] Step 7: Install welded steel ring plates at the location of the secondary enlarged hole in the basement floor slab, within the thickness range of the basement floor slab. Set bentonite waterstop strips at the convex step inside corner of the opening in the basement floor slab. Seal the gap between the steel casing and the basement floor slab cushion layer with compaction grouting.

[0035] Step 8: Cut the steel casing down to the basement floor slab surface, and use a pneumatic drill to remove the over-grouting at the top of the pile; connect the reinforcing bars of the basement floor slab to the steel ring plate, tie the pile cap reinforcing bars to the remaining steel casing, insert both ends of the pile cap reinforcing bars into the basement floor slab, anchor the pile foundation anchoring reinforcing bars into the pile cap, and after pre-embedding the grouting pipe, pour the pile cap concrete. This completes the construction of the basement floor slab supplementary piles.

[0036] Compared with existing technologies, this invention belongs to the field of urban renewal and relates to a construction method that integrates groundwater control and seepage prevention reinforcement of the basement floor slab during the construction of additional cast-in-place piles on the original basement foundation slab in the renovation of existing basement structures. This invention can solve the construction problems of difficulty in dewatering and leakage control during the construction of additional piles on the basement floor slab of existing basement structures.

[0037] This invention provides a novel water-stopping pile cap and sealing node design that can effectively prevent seepage. It also incorporates the MJS method (all-round high-pressure jet grouting) reinforcement and water-stopping principle, which can achieve groundwater (especially confined water) control measures, allowing the supplementary piles to be constructed without additional dewatering construction.

[0038] This invention integrates groundwater control and basement floor slab reinforcement functions in the construction of supplementary piles for urban renewal projects. It prevents groundwater and soil erosion, ensuring settlement control of the basement floor slab and surrounding underground pipelines. Through the combined action of novel water-stopping pile caps and sealing pile nodes, it effectively improves groundwater leakage problems caused by supplementary piles in the basement floor slab of urban renewal projects. Furthermore, the invention features simple construction steps, significantly reducing the amount of work required for drilling holes in the foundation basement floor slab, saving on dewatering control costs for basements (especially confined water systems), resulting in significant economic benefits. Attached Figure Description

[0039] Figure 1 This is a construction detail diagram of additional piles on the basement floor slab according to an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the opening and steel casing installation when selecting a low headroom equipment according to an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the opening and steel casing installation during conventional construction of a raised casing according to an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the opening in the basement floor slab according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of a steel ring plate node according to an embodiment of the present invention;

[0044] Figure 6 This is a cross-sectional view of a pile sealing node according to an embodiment of the present invention;

[0045] Figure 7 This is a plan view of a pile sealing node according to an embodiment of the present invention. Detailed Implementation

[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] like Figures 1 to 7 As shown, the present invention provides a basement floor slab re-piling structure with integrated groundwater control, comprising:

[0048] MJS reinforcement soil 2 is installed at the bottom of the pit under the basement floor slab;

[0049] A steel casing 1 is inserted through the opening 16 in the basement floor slab and into the MJS reinforced soil at the bottom of the pit under the basement floor slab. The steel casing 1 is higher than the basement floor slab.

[0050] An annular hoop plate 21 is installed in the opening 16 of the basement floor slab and located on the outer wall of the steel casing 1.

[0051] A steel ring plate 3 is installed in the opening of the basement floor slab and located on the outer wall of the annular hoop plate 21.

[0052] Vertical stiffening ribs 20 are located in the opening of the basement floor slab and are spaced apart on the outer wall of the annular hoop 21. The top of each vertical stiffening rib 20 is connected to the bottom wall of the steel ring plate 3, and the side wall of each vertical stiffening rib 20 is connected to the outer wall of the annular hoop 21.

[0053] The outer wall of the steel casing 1, which is higher than the basement floor slab, is welded with a bevel 6, and the bevel is welded to the surrounding basement floor slab reinforcing bars and reinforcing bars 8.

[0054] The pile cap 22, which covers the top of the opening 16 in the basement floor slab, is preferably made of waterproof, non-shrink concrete with a strength one grade higher than that of the pile body concrete.

[0055] Here, the top of the steel casing 1 is higher than the basement floor slab to facilitate the subsequent formation of pile top over-grouting 4.

[0056] In one embodiment of the integrated groundwater control basement floor slab reinforcement pile structure of the present invention, annular stirrups 5 are also provided around the steel casing 1.

[0057] Before placing the steel casing 1 into the opening, annular stirrups 5 can be placed first for positioning the steel casing 1. Then, the steel casing 1 is inserted into the annular stirrups 5. The height of the annular stirrups can be twice the height of the opening.

[0058] In one embodiment of the integrated groundwater control basement floor slab reinforcement pile structure of the present invention, the gap between the steel casing 1 and the basement floor slab and cushion layer is sealed by compaction grouting 7.

[0059] In one embodiment of the integrated groundwater control basement floor slab supplementary piling structure of the present invention, when a low headroom piling machine is used for construction, the steel casing 1 extends 300mm beyond the basement floor slab.

[0060] In one embodiment of the integrated groundwater control basement floor slab supplementary pile structure of the present invention, when conventional pile driving is used for construction, the steel casing passes through the basement floor slab cushion layer 15, the basement floor slab 14, the basement intermediate floor slab 13 and the basement roof slab 12 from bottom to top, and extends 300mm beyond the basement roof slab.

[0061] like Figure 4As shown, in one embodiment of the integrated groundwater control basement floor slab re-piling structure of the present invention, the openings in the basement floor slab include:

[0062] Pre-hole 29 for grouting of MJS reinforced soil;

[0063] 30 mm hole enlargement is used for inserting steel casings and for drilling and grouting pile construction.

[0064] 31 is used for welding steel ring plates 3 and for secondary hole enlargement during pile sealing node construction.

[0065] like Figure 6 As shown, in one embodiment of the integrated groundwater control basement floor slab supplementary pile structure of the present invention, a grouting pipe 23 is also pre-embedded in the pile cap 22, and one end of the grouting pipe 23 is connected to a grouting conduit 24.

[0066] like Figure 6 The plan view of the pile sealing node shown includes: cast-in-place pile 26, pile driving hole 27, and the two ends of the steel bars 28 of the pile cap 22 are inserted into the basement floor slab; the pile cap steel bars 25 are also welded to the longitudinal reinforcement of the pile foundation.

[0067] In one embodiment of the basement floor slab reinforcement pile structure with integrated groundwater control of the present invention, the steel casing 1 is grouted with micro-expansion concrete 10; the steel casing 1 is grouted with non-shrink concrete 11.

[0068] In one embodiment of the integrated groundwater control basement floor slab reinforcement pile structure of the present invention, a bentonite waterstop strip 9 is provided at the concave corner of the protruding step of the opening 16 in the basement floor slab.

[0069] According to another aspect of the present invention, a method for supplementing piles in basement floor slabs with integrated groundwater control is also provided, comprising:

[0070] like Figure 4 As shown, step 1: locate the center of the supplementary pile, and make a hole in the basement floor slab based on the center location of the supplementary pile. According to the center location of the supplementary pile, use an Atlas drilling rig to make a pilot hole 29 in the basement floor slab.

[0071] like Figure 1 As shown, Step 2: Pit bottom water-proofing construction: At the location of the pilot hole 29, the soil at the location of the pile foundation to be constructed is reinforced using the MJS reinforced soil 2 method. The planar range is a full circle with an MJS spray diameter of 2200-2400mm, and the reinforcement depth extends to 5 meters below the bottom of the basement floor slab.

[0072] like Figure 4 As shown, step 3: make an enlarged hole 30 in the basement floor slab: make an enlarged hole 30 in the basement floor slab using a combination of mechanical and manual methods. The diameter of the enlarged hole should be slightly larger than the diameter of the steel casing 1 to be embedded.

[0073] like Figure 1 As shown, step 4: Install steel casing 1 on the first enlarged hole 30. Steel casing 1 should be inserted 2 meters below the basement floor slab.

[0074] Step 5: Construction of additional pile foundations (such as cast-in-place piles): Figure 2 As shown, if low-headroom equipment is used for construction inside the basement, concrete will be poured to the lower part of the basement floor slab using the low-headroom equipment and short steel casing; if... Figure 3 As shown, if conventional equipment is used, the long steel casing is extended to the ground for construction, and the concrete on the ground is poured into the lower part of the basement floor through the long steel casing.

[0075] like Figure 4 As shown, step 6: A secondary enlarged hole 31 is drilled in the basement floor slab; the secondary enlarged hole 31 is shaped as a downwardly convex step according to the thickness H of the basement floor slab. Within the upper H / 2 range of the basement floor slab thickness H, the size of the secondary enlarged hole 31 is 1 meter larger than the pre-embedded steel casing 1; within the lower H / 2 range of the basement floor slab thickness H, the size of the enlarged hole is 0.5 meters larger than the pre-embedded steel casing 1. Note that the concrete within the area of ​​the main reinforcement of the basement floor slab must be removed manually using protective enlargement chiseling.

[0076] Step 7: Anti-seepage reinforcement measures for basement floor slab: At the location of the secondary enlarged hole 31 in the basement floor slab and within the thickness range of the basement floor slab, install welded steel ring plate 3; at the inner corner of the protruding step of the opening 16 in the basement floor slab, install bentonite waterstop strip 9; seal the gap between the steel casing 1 and the basement floor slab cushion layer 15 with compaction grouting.

[0077] Step 8: Pile sealing construction: Cut the steel casing 1 down to the basement floor slab surface, and use a pneumatic drill to remove the over-grouting at the top of the pile; connect the reinforcing bars of the basement floor slab to the steel ring plate 3, tie the pile cap reinforcing bars to the remaining steel casing 1, insert both ends of the pile cap reinforcing bars into the basement floor slab, anchor the pile foundation anchoring reinforcing bars into the pile cap, and after pre-embedding the grouting pipe (for subsequent leak sealing), pour the pile cap concrete. This completes the construction of the additional piles for the basement floor slab.

[0078] In step 5, underwater micro-expansion concrete is preferred.

[0079] In step 8, waterproof, non-shrink concrete is preferred for sealing the piles, and its strength is increased by one grade compared to the original foundation basement slab concrete.

[0080] This invention belongs to the field of urban renewal and relates to a construction method that integrates groundwater control and seepage prevention reinforcement of the basement floor slab during the construction of additional cast-in-place piles on the original basement foundation slab for the renovation of existing basement structures. This invention can solve the construction problems of difficulty in dewatering and leakage control during the construction of additional piles on the basement floor slab of existing basement structures.

[0081] This invention provides a novel water-stopping pile cap and sealing node design that can effectively prevent seepage. It also incorporates the MJS method (all-round high-pressure jet grouting) reinforcement and water-stopping principle, which can achieve groundwater (especially confined water) control measures, allowing the supplementary piles to be constructed without additional dewatering construction.

[0082] This invention integrates groundwater control and basement floor slab reinforcement functions in the construction of supplementary piles for urban renewal projects. It prevents groundwater and soil erosion, ensuring settlement control of the basement floor slab and surrounding underground pipelines. Through the combined action of novel water-stopping pile caps and sealing pile nodes, it effectively improves groundwater leakage problems caused by supplementary piles in the basement floor slab of urban renewal projects. Furthermore, the invention features simple construction steps, significantly reducing the amount of work required for drilling holes in the foundation basement floor slab, saving on dewatering control costs for basements (especially confined water systems), resulting in significant economic benefits.

[0083] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0084] Obviously, those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A basement floor slab re-piling structure integrating groundwater control, characterized in that, include: MJS reinforcement soil is installed at the bottom of the pit under the basement floor slab; A steel casing is inserted through an opening in the basement floor slab and into the MJS reinforced soil at the bottom of the pit beneath the basement floor slab, with the steel casing extending above the basement floor slab. A ring-shaped hoop plate is installed in the opening in the basement floor slab and located on the outer wall of the steel casing. A steel ring plate is installed in the opening of the basement floor slab and located on the outer wall of the annular hoop plate. Vertical stiffening ribs are located in the opening of the basement floor slab and are spaced apart on the outer wall of the annular hoop. The top of each vertical stiffening rib is connected to the bottom wall of the steel ring plate, and the side wall of each vertical stiffening rib is connected to the outer wall of the annular hoop. The outer wall of the steel casing that extends above the basement floor slab is welded with a bevel, which is welded to the surrounding basement floor slab reinforcement bars and reinforcing bars. A pile cap covering the opening in the basement floor slab.

2. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, The steel casing is also surrounded by annular stirrups.

3. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, The gap between the steel casing and the basement floor slab and subbase is sealed by compaction grouting.

4. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, When using a low-headroom pile driver, the steel casing extends beyond the basement floor slab.

5. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, When conventional pile drivers are used for construction, the steel casing passes through the basement floor slab, basement floor, basement intermediate floor slab, and basement roof slab sequentially from bottom to top, and extends out of the basement roof slab.

6. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, The openings in the basement floor slab include: Pre-holes used for grouting of MJS reinforced soil; A primary hole enlargement method used for inserting steel casings during bored pile construction; Used for secondary hole enlargement in the construction of welded steel ring plates and pile sealing nodes.

7. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, The pile cap is also pre-embedded with a grouting pipe, and one end of the grouting pipe is connected to a grouting conduit.

8. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, The steel casing is filled with micro-expansion concrete; the steel casing is filled with non-shrink concrete.

9. The basement floor slab re-piling structure with integrated groundwater control as described in claim 1, characterized in that, Bentonite waterstop strips are installed at the inside corner of the protruding steps where the opening is located in the basement floor slab.

10. A method for supplementing piles in basement floor slabs with integrated groundwater control, characterized in that, The method employs the integrated groundwater control piling structure for basement floor slabs as described in any one of claims 1 to 9, the method comprising: Step 1: Based on the center positioning of the supplementary pile, use an Atlas drilling rig to drill pilot holes in the basement floor slab; Step 2: At the location of the pilot hole, the soil at the location of the pile foundation to be constructed is reinforced using the MJS soil reinforcement method; Step 3: Make an enlarged hole in the basement floor slab, with the diameter of the enlarged hole slightly larger than the diameter of the steel casing to be embedded; Step 4: Install a steel casing on the primary borehole, inserting the steel casing below the basement floor slab; Step 5: If low-headroom equipment is used for construction inside the basement, concrete is poured to the bottom of the basement floor slab through the low-headroom equipment and short steel casing; if conventional equipment is used, the long steel casing is extended to the ground for construction, and concrete is poured from the ground to the bottom of the basement floor slab through the long steel casing. Step 6: Open a secondary enlarged hole in the basement floor slab; the secondary enlarged hole is shaped as a downward convex step according to the thickness H of the basement floor slab. Within the upper H / 2 range of the thickness H of the basement floor slab, the size of the secondary enlarged hole is 1 meter beyond the pre-embedded steel casing; within the lower H / 2 range of the thickness H of the basement floor slab, the size of the enlarged hole is 0.5 meters beyond the pre-embedded steel casing. Step 7: Install welded steel ring plates at the location of the secondary enlarged hole in the basement floor slab, within the thickness range of the basement floor slab. Set bentonite waterstop strips at the convex step inside corner of the opening in the basement floor slab. Seal the gap between the steel casing and the basement floor slab cushion layer with compaction grouting. Step 8: Cut the steel casing down to the basement floor slab surface, and use a pneumatic drill to remove the over-grouting at the top of the pile; connect the reinforcing bars of the basement floor slab to the steel ring plate, tie the pile cap reinforcing bars to the remaining steel casing, insert both ends of the pile cap reinforcing bars into the basement floor slab, anchor the pile foundation anchoring reinforcing bars into the pile cap, and after pre-embedding the grouting pipe, pour the pile cap concrete. This completes the construction of the basement floor slab supplementary piles.

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