Anti-seismic and anti-leakage flexible shaft structure and construction method thereof

Abstract

The application discloses a flexible shaft well structure with anti-seismic and anti-seepage functions and a construction method thereof, and belongs to the field of building construction. The flexible shaft well structure comprises a reinforced concrete lining and a load-bearing ring arranged outside the reinforced concrete lining, the load-bearing ring is formed by circumferentially overlapping a plurality of flexible piles around the reinforced concrete lining, the flexible piles are formed by consolidating a permeable polymer and sand, and a polymer waterproof shock insulation buffer layer is arranged between the reinforced concrete lining and the load-bearing ring, and the polymer waterproof shock insulation buffer layer is formed by expanding a polymer grouting layer. The shaft well structure has high anti-seismic and anti-seepage performances, and is suitable for a coastal coral sand reclamation layer. A flexible load-bearing ring with anti-seismic and anti-seepage functions is formed by polymer permeation grouting, a polymer waterproof shock insulation buffer layer is formed by grouting between the reinforced concrete lining structure and the load-bearing ring, and the whole structure has anti-seismic and anti-seepage effects. In the excavation process, complicated dewatering operations are not needed, and a large amount of financial resources and time are saved.

Description

Technical Field

[0001] This invention relates to the field of building engineering, and in particular to a resilient shaft structure with earthquake resistance and seepage prevention, and its construction method. Background Technology

[0002] Land reclamation in coastal areas is often carried out through hydraulic filling, with coral sand being the primary filling material. Due to the irregular shape, high porosity, and fragility of coral sand particles, often accompanied by cementation, its engineering properties differ significantly from those of terrestrial quartz sand. This makes excavating shafts in coral sand-filled geology quite challenging. Traditional support methods applied to coral sand-filled geology suffer from poor durability and impermeability. Earthquakes in coastal areas could lead to catastrophic damage to shaft structures, necessitating urgent optimization of the seismic and seepage-proof functions of shaft structures in coral sand land reclamation projects. Summary of the Invention

[0003] This invention provides a resilient shaft structure with earthquake resistance and seepage prevention, and its construction method, to solve the technical problems of insufficient seepage resistance and earthquake resistance in shafts constructed on coral sand geology.

[0004] To address the aforementioned technical problems, one objective of this invention is to provide a resilient shaft structure that is earthquake-resistant and seepage-proof, comprising a reinforced concrete lining and a bearing ring surrounding the outside of the reinforced concrete lining. The bearing ring is formed by a plurality of resilient piles circumferentially overlapping around the reinforced concrete lining. The resilient piles are formed by consolidation of a permeable polymer with sand. A polymer waterproof and seismic isolation buffer layer is provided in the space between the reinforced concrete lining and the bearing ring. The polymer waterproof and seismic isolation buffer layer is composed of an expandable polymer.

[0005] As a preferred embodiment, the resilient piles are configured as either frustum-shaped or cylindrical structures, both using an interlocking pile arrangement, and the reinforced concrete lining is cylindrical.

[0006] As a preferred option, the diameter of the bottom surface of the truncated cone-shaped resilient pile is 2m and the diameter of the top surface is 1m; the diameter of the cylindrical resilient pile is 1.5m.

[0007] As a preferred embodiment, when the resilient pile is configured as a frustum-shaped structure, the bottom distance between the bearing ring and the reinforced concrete lining is 0.2±0.05m, the top distance is 0.7±0.05m, and the interlocking width between adjacent resilient piles at the top is 0.2-0.3m.

[0008] As a preferred embodiment, when the toughening column is set as a cylindrical structure, the distance between the bearing ring (2) and the reinforced concrete lining (1) is 0.2-0.5m, and the interlocking width between adjacent toughening piles is 0.2-0.4m.

[0009] As a preferred embodiment, the polymer waterproof and shock-absorbing buffer layer is composed of a non-aqueous reactive polyurethane-type expandable polymer.

[0010] To address the aforementioned technical problems, a second objective of this invention is to provide a construction method for a seismically resistant and seepage-proof resilient shaft structure, comprising the following steps:

[0011] (1) Drill holes to a predetermined depth on the ground, seal the holes above a portion of the cavity by injecting polymer into the membrane bag to expand it, inject polymer into the cavity below the membrane bag using a permeation grouting pipe, and use pressure permeation to solidify the polymer with the surrounding tissue to form a spherical solid body. After grouting is completed, re-place the membrane bag to seal the hole and perform pressure grouting permeation in the upper cavity until the top of the borehole is reached to form a tough pile.

[0012] (2) Adjacent to the tough piles, tough piles are made in the manner of step (1), and adjacent tough piles are arranged in a circumferential direction and overlap each other to form a circular bearing ring.

[0013] (3) The reinforced concrete lining is manufactured by prefabrication, and the reinforced concrete lining is assembled in layers inside the bearing ring and constructed by caisson construction.

[0014] (4) An expanded polymer is injected between the reinforced concrete lining and the bearing ring to form a polymer waterproof and seismic isolation buffer layer, which is then bonded to the bearing ring and the reinforced concrete lining respectively.

[0015] As a preferred option, in step (1), the polymer injected into the cavity below the membrane bag by the permeation grouting pipe is a permeation-type polymer material.

[0016] As a preferred embodiment, in step (1), the polymer injected into the membrane bag is a non-aqueous reactive polyurethane-based expandable polymer; in step (4), the polymer injected into the grouting hole is a non-aqueous reactive polyurethane-based expandable polymer.

[0017] As a preferred option, in step (1), after the membrane bag is expanded, it is larger than the diameter of the drilled hole. The membrane bag is then grouted with polymer using a sealing grouting pipe. The sealing grouting pipe is pulled out before the expanding polymer is fully cured.

[0018] As a preferred option, in step (1), when the tough pile is a variable cross-section frustum cylindrical structure, the grouting volume of the permeation grouting pipe decreases as the depth decreases; when the tough pile is a uniform cross-section cylindrical structure, the permeation grouting volume is controlled to be the same each time.

[0019] As a preferred option, in step (4), grouting holes and venting holes are reserved in the reinforced concrete lining. Polymer is injected between the reinforced concrete lining and the bearing ring using the grouting holes. Grouting is stopped when grout is discharged from the venting holes, and the grouting holes and venting holes are sealed. The expandable polymer expands, forms a certain strength, and tightly bonds the reinforced concrete lining and the bearing ring.

[0020] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0021] This application describes a shaft structure with high seismic and seepage resistance. It is suitable for coastal coral sand reclamation layers. A resilient, seismic-resistant, and seepage-proof bearing ring is formed through polymer-based infiltration grouting, serving as an outer reinforcement structure to protect the interior. The interior is constructed using a caisson method, with layered excavation and assembly to form the main reinforced concrete lining structure. After the internal reinforced concrete lining is completed, polymer grouting is applied between the lining and the bearing ring to form a polymer waterproof and seismic-isolated buffer layer, providing shock absorption and waterproofing. Combined with the seepage-proof function of the outer resilient bearing ring, the overall structure achieves seismic resistance and seepage prevention. This structure eliminates the need for cumbersome dewatering operations during excavation, saving significant financial and time resources. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the construction process of a bearing ring in a resilient shaft structure with earthquake resistance and seepage prevention, according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram illustrating a construction method for variable cross-section resilient piles in a seismically resistant and seepage-proof resilient shaft structure according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of a resilient pile in a resilient shaft structure for earthquake resistance and seepage prevention, according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram illustrating a construction method for a medium-section tough pile in a seismically resistant and seepage-proof tough shaft structure according to an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the interlocking structure between adjacent tough piles at the top in a tough shaft structure for earthquake resistance and seepage prevention according to an embodiment of the present invention.

[0027] Figure 6 This is a top view of the load-bearing ring in a resilient shaft structure with earthquake resistance and seepage prevention according to an embodiment of the present invention.

[0028] Figure 7 This is a schematic cross-sectional view of a resilient shaft structure with earthquake resistance and seepage prevention, based on an embodiment of the present invention, using variable cross-section piles.

[0029] Figure 8 This is a schematic cross-sectional view of a resilient shaft structure with earthquake resistance and seepage prevention, based on an embodiment of the present invention, using piles with equal cross-sections.

[0030] The instruction manual includes Figure 7-8 The attached diagrams are labeled as follows: 1. Reinforced concrete lining; 11. Grouting pipe; 2. Bearing ring; 3. Polymer waterproof and seismic isolation buffer layer. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] A resilient shaft structure with earthquake resistance and seepage prevention includes a cylindrical reinforced concrete lining 1, which is set inside coral sand. The reinforced concrete lining 1 has pre-installed grouting pipes 11 and vent holes. A bearing ring 2 is circumferentially arranged around the perimeter of the reinforced concrete lining 1. The bearing ring 2 is formed by several resilient piles overlapping circumferentially around the perimeter of the reinforced concrete lining. The resilient piles are either frustum-shaped or cylindrical. When the resilient piles are frustum-shaped, the bottom distance between the bearing ring and the reinforced concrete lining is 0.2±0.05m, the top distance is 0.7±0.05m, the bottom diameter of the resilient pile is 2m, the top diameter is 1m, and the interlocking width between adjacent resilient piles at the top is 0.2-0.3m. When the resilient piles are cylindrical, the diameter is 1.5m, the distance between the bearing ring and the reinforced concrete lining is 0.2-0.5m, and the interlocking width between adjacent resilient piles is 0.2-0.4m. The resilient pile is formed by consolidation of coral sand and polymer A, specifically a permeable polymer. A polymer waterproof and seismic isolation buffer layer 3 is formed between the reinforced concrete lining 1 and the bearing ring 2. The polymer waterproof and seismic isolation buffer layer 3 is composed of polymer B, specifically a non-aqueous reactive polyurethane-type expandable polymer.

[0034] The construction method of the above-mentioned earthquake-resistant and seepage-proof vertical shaft structure includes the following steps:

[0035] (1) Construction of the load-bearing ring:

[0036] like Figure 1-2As shown, a borehole is drilled downwards on the coral sand geological surface. After drilling, a casing is inserted to prevent borehole collapse. The borehole diameter is large enough for the insertion of both the permeation grouting pipe and the sealing grouting pipe. Before grouting, the casing is raised to leave space for grouting. The permeation grouting pipe is then placed to the bottom of the borehole. A sealing membrane bag is then fitted over the end of the sealing grouting pipe and secured with a pipe clamp (not necessarily tightly) to facilitate removal of the sealing grouting pipe after grouting. The pipe is then inserted to a predetermined depth within the borehole. A non-aqueous reactive polyurethane-based expanding polymer is injected into the membrane bag through the sealing grouting pipe for sealing. The membrane bag is an impermeable geotextile, bag-shaped, and when expanded, it will be slightly larger than the borehole diameter. After injecting non-aqueous polyurethane expandable polymer into the membrane bag through the sealing grouting pipe, the membrane bag expands. Before it is fully cured, the sealing grouting pipe is pulled out. After the polymer in the membrane bag is fully cured, a permeable polymer material is injected into the cavity below the sealing hole using a permeation grouting pipe. The permeable polymer material forms a spherical solid with the coral sand through permeation consolidation. After grouting is completed, the casing is raised again and the permeation grouting pipe is placed above it again. The membrane bag is placed at a certain position above the opening of the permeation grouting pipe and grouting is performed again to seal the hole. The grouting of the entire borehole depth is repeated multiple times until the wellhead position is reached.

[0037] like Figure 3 As shown, considering that the soil pressure increases with depth, in order to optimize the material configuration, the tough pile in this embodiment is a variable cross section pile, that is, the tough pile is a frustum-shaped structure. The pile is formed by permeation grouting. The amount of grouting of the permeable polymer material decreases with the decrease of depth. The pressure permeation method is used to form a frustum-shaped tough pile with a bottom diameter of 2m and an opening diameter of 1m.

[0038] The specific grout diffusion radius can be determined based on the spherical permeability theory of Newtonian fluid grout in sand established by Maag in 1938. When the grouting method is end-hole grouting, the grout diffuses in a spherical shape, and the diffusion radius R is expressed as:

[0039]

[0040] Where t is the grouting time (s), R is the grout diffusion and penetration radius (cm), β is the viscosity ratio of grout to water, n is the porosity of the injected carrier, k is the permeability coefficient of the injected carrier (cm / s), h1 is the grouting pressure (cm), r0 is the grouting pipe radius (cm), and P is the grouting pressure (Pa).

[0041] Furthermore, for ease of construction, uniform cross-section piles can also be used, with a preferred grout diffusion diameter of 1.5m. Figure 4 As shown;

[0042] (2) Use the same method to construct resilient piles at adjacent locations, with adjacent resilient piles overlapping each other circumferentially along the perimeter of the shaft, such as... Figure 5As shown, the interlocking width between adjacent ductile piles at the top is a, 0.2≤a≤0.3m, ultimately forming a hollow, frustum-shaped ductile bearing ring with a gradually changing cross-section, thicker at the bottom and thinner at the top. Figure 6 As shown;

[0043] (3) Reinforced concrete lining: such as Figure 7 As shown, reinforced concrete lining segments are prefabricated, and caisson construction is carried out within the bearing ring. The reinforced concrete lining forms a cylindrical vertical shaft structure. The distance between the reinforced concrete lining and the bearing ring gradually decreases from top to bottom, with a bottom distance of 0.2±0.05m and a top distance of 0.7±0.05m, ensuring a waterproof and seismic isolation buffer layer of at least 0.2m thickness. However, when the cylindrical structure is used for uniform cross-section piles (i.e., resilient piles), the distance between the reinforced concrete lining and the bearing ring is 0.2m-0.5m, and the interlocking width between adjacent resilient piles is a, where 0.2≤a≤0.4m. Figure 8 As shown;

[0044] (4) Polymer waterproof and shock-absorbing buffer layer: such as Figure 7 As shown, after the construction of the reinforced concrete lining inside the bearing ring is completed, non-aqueous polyurethane-based expandable polymer material is injected in layers from the bottom to the top of the well between the reinforced concrete lining and the bearing ring through the grouting holes reserved on the reinforced concrete lining. The non-aqueous polyurethane-based expandable polymer material expands to form a polymer waterproof and shock-absorbing buffer layer, which is bonded to the bearing ring and the reinforced concrete lining. Grouting holes and vent holes are reserved on the segments. Non-aqueous polyurethane-based expandable polymer is injected through the grouting holes. Grouting is stopped when grout is discharged from the vent holes, and the grouting holes and vent holes are sealed.

[0045] The specific type of permeable polymer material selected, but not limited to, is the PEC-RF permeable polymer material produced by Shaoguan Xinfeng Boxing Polymer Materials Co., Ltd. This material can undergo a gelation and curing reaction when it comes into contact with water, and only 5% of the grout mass of water is required for the reaction to occur. If the water content in the sand is higher than 5% of the grout volume, the reaction can still occur. The gelation time after grouting is 13 minutes, and the complete curing time is 30 minutes. It can form a reinforced structure with coral sand to protect the polymer waterproof and shock-absorbing buffer layer and the reinforced concrete lining.

[0046] The expanded polymer material is a non-aqueous reactant polyurethane expanded polymer, specifically the wanfoam_9802 polyurethane expanded polymer produced by Wanhua Energy Conservation Technology Group Co., Ltd. It is a two-component material, mixed in a 1:1 mass ratio, reacting to form a waterproof foam structure. It possesses high toughness and extremely high waterproofness, and will not undergo brittle fracture under pressure. The polyurethane expanded polymer also has high adhesion, allowing it to bond tightly to both the load-bearing ring and the reinforced concrete lining, ensuring no leakage channels are formed between the interfaces. It serves as a waterproof and seismic isolation agent between the load-bearing ring and the reinforced concrete lining.

[0047] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A resilient shaft structure with earthquake resistance and seepage prevention, characterized in that, It includes a reinforced concrete lining (1) and a bearing ring (2) surrounding the outside of the reinforced concrete lining (1). The bearing ring (2) is formed by several tough piles circumferentially overlapping around the reinforced concrete lining (1). The tough piles are formed by consolidation of a permeable polymer and sand. A polymer waterproof and seismic isolation buffer layer (3) is provided in the space between the reinforced concrete lining (1) and the bearing ring (2). The polymer waterproof and seismic isolation buffer layer (3) is composed of an expansive polymer. The resilient piles are configured as frustum-shaped columns, all arranged in an interlocking pile configuration, with the interlocking width between adjacent resilient piles at the top being 0.2-0.3m. The polymer waterproof and shock-absorbing buffer layer is composed of a non-aqueous reactant polyurethane-type expandable polymer, and the thickness of the polymer waterproof and shock-absorbing buffer layer is at least 0.2 m.

2. The earthquake-resistant and seepage-proof tough shaft structure as described in claim 1, characterized in that, The reinforced concrete lining (1) is cylindrical; The diameter of the bottom surface of the truncated cone-shaped resilient pile is 2m, and the diameter of the top surface is 1m.

3. The earthquake-resistant and seepage-proof tough shaft structure as described in claim 1, characterized in that, When the resilient pile is configured as a frustum column structure, the bottom distance between the bearing ring (2) and the reinforced concrete lining (1) is 0.2±0.05m, and the top distance is 0.7±0.05m.

4. A construction method for a resilient shaft structure with earthquake resistance and seepage prevention as described in any one of claims 1-3, characterized in that, Includes the following steps: (1) Drill holes to a predetermined depth on the ground, and seal the holes above a portion of the cavity by injecting polymer into the membrane bag to expand it. Then, inject polymer into the cavity below the membrane bag using a permeation grouting pipe. Use pressure permeation to solidify the polymer with the surrounding tissue to form a spherical solid body. After grouting is completed, re-place the membrane bag in the upper cavity to seal the hole and perform pressure grouting permeation until the top of the borehole is reached to form a tough pile. (2) Adjacent to the tough piles, tough piles are made in the manner of step (1), and adjacent tough piles are arranged in the circumferential direction and overlap each other to form a circular bearing ring. (3) The reinforced concrete lining is manufactured by prefabrication, and the reinforced concrete lining is assembled in layers inside the bearing ring and constructed by caisson construction. (4) Inject an expanding polymer between the reinforced concrete lining and the bearing ring to form a polymer waterproof and shock-absorbing buffer layer, and bond it to the bearing ring and the reinforced concrete lining respectively.

5. The construction method of a seismically resistant and seepage-proof tough shaft structure as described in claim 4, characterized in that, In step (1), the polymer injected into the cavity below the membrane bag by the permeation grouting pipe is a permeation type polymer material.

6. The construction method of a seismically resistant and seepage-proof tough shaft structure as described in claim 4, characterized in that, In step (1), the polymer injected into the membrane bag is a non-aqueous reactant polyurethane-based expandable polymer; in step (4), the polymer injected into the grouting hole is a non-aqueous reactant polyurethane-based expandable polymer.

7. The construction method of a seismically resistant and seepage-proof tough shaft structure as described in claim 4, characterized in that, In step (1), after the membrane bag is expanded, it is larger than the diameter of the drilled hole. The membrane bag is grouted with polymer using a sealing grouting pipe. The sealing grouting pipe is pulled out before the expanded polymer is completely cured.

8. The construction method of a seismically resistant and seepage-proof tough shaft structure as described in claim 4, characterized in that, In step (1), when the tough pile is a variable cross-section frustum cylindrical structure, the grouting volume of the permeation grouting pipe decreases as the depth decreases.

9. The construction method of a resilient shaft structure with earthquake resistance and seepage prevention as described in claim 4, characterized in that, In step (4), grouting holes and venting holes are reserved in the reinforced concrete lining. Polymer is injected between the reinforced concrete lining and the bearing ring using the grouting holes. Grouting is stopped when grout is discharged from the venting holes, and the grouting holes and venting holes are sealed. The expandable polymer expands, forms a certain strength, and tightly bonds the reinforced concrete lining and the bearing ring.

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