Waterproof and drainage structure in hard rock oversized span cave depot single-layer lining and construction method

Abstract

The invention discloses a waterproof and drainage structure in a hard rock ultra-large span cave depot single-layer lining and a construction method, and relates to the technical field of ultra-large span underground engineering drainage, the waterproof and drainage structure comprises a cave surrounding rock, main water seepage cracks are formed in the cave surrounding rock, and the waterproof and drainage structure comprises a waterproof concrete layer, an elastic waterproof cushion layer and a reinforced concrete layer which are sequentially arranged from left to right; the main water seepage cracks are treated before the waterproof concrete layer is constructed, a treatment assembly is arranged in the main water seepage cracks, a drainage assembly is arranged in the elastic waterproof cushion layer, and the treatment assembly is connected with the drainage assembly; by means of the measures such as structure durability, three-level waterproof barriers formed by the waterproof concrete layer, the elastic waterproof cushion layer and the reinforced concrete layer and the drainage net, the underground water seepage path is effectively blocked, lining steel bar corrosion is delayed, the service life of the structure is prolonged, and long-term reliable waterproof protection is provided for the ultra-large-span cavern.

Description

Technical Field

[0001] The invention relates to the technical field of drainage of ultra-large-span underground projects, and in particular to a drainage prevention structure and a construction method in a single-layer lining of an ultra-large-span hard rock cavern. Background Art

[0002] In the construction of super-large-span hard rock caverns, as the span increases, the lining structure faces more complex deformation and seepage pressure problems. Especially for super-large-span underground caverns with a span of 80 meters, the lining thickness is limited, and the conventional drainage system is difficult to effectively cope with the deformation and seepage challenges it brings. Traditional drainage designs usually rely on rigid structures, which can easily lead to structural cracking, leakage and other problems when faced with caverns with large spans and large deformations. The layout of waterproof drainage pipes in the existing technology often has defects such as unreasonable layout and blocked drainage channels. It fails to effectively consider the convergence deformation of the cavern and the change in water flow pressure, resulting in water stagnation or pipe blockage, thereby affecting the long-term stability of the system.

[0003] At the same time, traditional drainage systems also face great challenges in maintenance, especially in complex underground environments, where drainage facilities are easily blocked or corroded by sediment, resulting in reduced drainage effects and increased maintenance costs in long-term operations. In addition, the installation and commissioning of traditional systems during construction are cumbersome, the construction cycle is long, and often requires a lot of manpower and on-site adjustments, which not only increases construction costs, but also affects the construction progress of the project. Therefore, there is an urgent need for a new drainage system that can effectively adapt to the special needs of ultra-large span caverns and provide a more reliable drainage solution. Summary of the invention

[0004] In view of the above technical problems, the present invention discloses a waterproof and drainage structure in a single-layer lining of a hard rock super-large-span cavern, comprising cavern surrounding rock, wherein the cavern surrounding rock has main water seepage fissures, the waterproof and drainage structure comprises a waterproof concrete layer, an elastic waterproof cushion layer and a reinforced concrete layer arranged in sequence from left to right, the main water seepage fissures are treated before the waterproof concrete layer is applied, a treatment component is arranged in the main water seepage fissures, a drainage component is arranged in the elastic waterproof cushion layer, and the treatment component is connected to the drainage component; The processing component comprises a sand filter pipe, wherein the sand filter pipe is a gravel sand filter pipe, and a gravel layer is arranged in the sand filter pipe.

[0005] Furthermore, the waterproof concrete layer includes a first layer of waterproof concrete, which is applied on the outside of the cavern surrounding rock. When applying the first layer of waterproof concrete, a plurality of stainless steel brackets are embedded, and the plurality of stainless steel brackets are evenly distributed along the height direction of the cavern surrounding rock.

[0006] Furthermore, the elastic waterproof cushion layer includes an elastic cushion layer, the elastic cushion layer adopts polyurethane elastomer, is sprayed on site, and has seamless seams. The drainage component is arranged in the elastic cushion layer, and a polyurea waterproof coating is sprayed on the outer side of the elastic cushion layer.

[0007] Furthermore, the reinforced concrete layer includes a concrete canvas, which is connected to the polyurea waterproof coating. A circular hole is opened on the concrete canvas, and an anchor rod is arranged in the circular hole. The anchor rod is connected to the drainage component, and a steel mesh is hung on the anchor rod. After reinforcing concrete is sprayed on the steel mesh, a primary lining concrete is formed. An inspection door is arranged on the reinforced concrete layer.

[0008] Furthermore, the drainage assembly includes two drainage pipes, and the two drainage pipes are connected by a six-way head. One drainage pipe penetrates the six-way head from bottom to top, and the other drainage pipe penetrates the six-way head from right to left. The anchor rod is inserted from the rear end access port of the six-way head, and the anchor rod is passed out from the front end access port of the six-way head. The connection between the six-way head and the drainage pipe is provided with a sealing ring, the front end access port of the six-way head is provided with a sealing ring, and the rear end access port of the six-way head is not provided with a sealing ring. The drainage pipe is made of high-density ethylene material, the drainage pipe is connected to a stainless steel bracket, and the drainage pipe is connected to a sand filter pipe through a flexible joint.

[0009] Furthermore, the appearance of the drainage pipe is a gradient design with a thick bottom and a thin top.

[0010] Furthermore, a detachable sand filter assembly is connected to the bottom of the drain pipe, and the position of the detachable sand filter assembly matches the position of the inspection door. The detachable sand filter assembly includes a sand filter tank, and a water inlet is arranged at the top of the sand filter tank, and the water inlet is connected to the bottom of the drain pipe. A quartz sand layer and a gravel layer are arranged in sequence from top to bottom in the sand filter tank, and a filter tube is arranged in the gravel layer, and the filter tube is connected to the interior of the sand filter tank. A water outlet is connected to the filter tube, and the water outlet is connected to the bottom end of the sand filter tank, and the water outlet is connected to a drainage ditch.

[0011] Furthermore, a plurality of evenly distributed drainage pipes are connected to the sand filter tank.

[0012] The present invention also discloses a construction method of a waterproof and drainage structure in a single-layer lining of a hard rock super-large span cavern, and the specific steps are as follows: Step 1: The surrounding rock of the cavern is scanned by geological radar, then cored by drilling, and the treatment component is placed in the borehole; Step 2: Install the drainage pipe and anchor rod, apply a waterproof concrete layer and pre-embed multiple stainless steel brackets, connect the drainage pipe with the multiple stainless steel brackets, and then connect the drainage pipe with the anchor rod through a six-way head; Step 3: Apply elastic waterproof cushion layer, spray the elastic cushion layer on the waterproof concrete layer, cover the drainage pipe and the first layer of waterproof concrete, and then spray the polyurea waterproof coating on the outside of the elastic cushion layer; Step 4: A removable sand filter assembly is connected every 20 meters along the length direction of the surrounding rock of the cavern, and the bottom of all drainage pipes within each 20-meter interval is connected to the removable sand filter assembly; Step 5: Apply a reinforced concrete layer on the outer layer of the polyurea waterproof coating.

[0013] The beneficial effects of the present invention compared with the prior art are: (1) Excellent deformation adaptability. Through the combination of elastic cushion layer and polyurea waterproof coating, a certain sliding space is reserved between the drainage pipe and the stainless steel bracket, which can adapt to the convergence deformation of the 80-meter span cavern. Compared with traditional rigid structures, the risk of leakage is reduced and the structural durability is significantly improved; (2) The active drainage system improves structural safety by installing sand filter pipes at the seepage cracks to pre-treat the concentrated water flow, and combines a drainage pipe network with a thick bottom and a thin top, using a six-way head to integrate the anchor rod and the sand filter pipe outlet to achieve an efficient drainage path design. This system actively guides the discharge of groundwater to avoid direct erosion of the lining structure by water pressure, significantly reduces the risk of leakage, and enhances the safety of the cavern; (3) The modular maintenance design extends the life of the system. By combining the switchable inspection door with the stainless steel filter sand tank, the filter sand pipe is used for primary coarse filtration and the stone filter sand tank is used for secondary fine filtration to realize a graded filtration system. The sediment interception efficiency is improved. The impurities in the quartz sand filter layer can also be cleaned regularly to prevent the drain pipe from being blocked and reduce the subsequent maintenance cost. The stainless steel filter sand tank and bracket have enhanced corrosion resistance and adapt to humid environments, which significantly improves the durability and service life of the drainage system.

[0014] (4) Improved construction efficiency and economy. The six-way integrated drainage and anchor rod positioning waterproofing functions reduce the number of on-site drilling and connectors, shorten the construction period, and the drainage pipe is light and durable. The polyurethane elastomer spraying process simplifies the process and reduces labor costs, taking into account both construction efficiency and economy. (5) To ensure the durability of the structure, the waterproof concrete layer, elastic cushion layer and polyurea coating form a three-level waterproof barrier, and measures such as drainage nets can effectively block the groundwater infiltration path, delay the corrosion of lining steel bars, extend the life of the structure, and provide long-term and reliable waterproof protection for ultra-large span caverns.

[0015] (6) Convenient construction and structural integration, modular prefabricated drainage pipes, sand filter pipes and spray-formed elastic cushion layers reduce on-site joints and improve construction efficiency; the integrated design of anchor rods, six-way heads and steel mesh achieves synchronization of drainage and initial support, shortening the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the super-large span single-layer lining cavern waterproofing and drainage structure of the present invention.

[0017] Figure 2 This is a cross-sectional view of the ultra-large span single-layer lining cavern drainage structure of the present invention.

[0018] Figure 3 It is a schematic diagram of the connection relationship between the anchor rod and the drainage pipe of the present invention.

[0019] Figure 4 It is a schematic diagram of the internal structure of the sand filter tank of the present invention.

[0020] Figure 5 It is a schematic diagram of the structure of the sand filter tube of the present invention.

[0021] Figure numbers: 1-sand filter pipe; 2-drain pipe; 3-first layer of waterproof concrete; 4-stainless steel bracket; 5-six-way head; 6-anchor rod; 7-elastic cushion; 8-polyurea waterproof coating; 9-sand filter tank; 10-concrete canvas; 11-primary lining concrete; 12-drainage ditch; 13-inspection door; 14-main seepage cracks; 15-sealing ring; 16-gravel layer; 17-water inlet; 18-quartz sand layer; 19-filter tube; 20-water outlet. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0025] Example: Figure 1-Figure 5 As shown, a waterproof and drainage structure in a single-layer lining of a hard rock super-large-span cavern includes a cavern surrounding rock, wherein there are main water seepage fissures 14 in the cavern surrounding rock, and the waterproof and drainage structure includes a waterproof concrete layer, an elastic waterproof cushion layer and a reinforced concrete layer arranged in sequence from left to right. Before the waterproof concrete layer is applied, the main water seepage fissures 14 are first treated, a treatment component is arranged in the main water seepage fissures 14, a drainage component is arranged in the elastic waterproof cushion layer, and the treatment component is connected to the drainage component; the treatment component includes a sand filter pipe 1, and the sand filter pipe 1 adopts a gravel sand filter pipe, and a gravel layer 16 is arranged in the sand filter pipe 1, and a filter layer is formed by the accumulation of the gravel layer 16, the particle size of the gravel in the gravel layer 16 is 10-20mm, the pores between the gravel layers 16 are large, and the water permeability is good, which meets the large-flow drainage demand in the tunnel, so that the water flow quickly passes through the sand filter pipe 1 into the drainage component for discharge.

[0026] The waterproof concrete layer includes a first layer of waterproof concrete 3, which is applied outside the cavern surrounding rock. During application, a plurality of stainless steel brackets 4 are embedded in the first layer of waterproof concrete 3, and the plurality of stainless steel brackets 4 are evenly distributed along the height direction of the cavern surrounding rock.

[0027] The elastic waterproof cushion layer includes an elastic cushion layer 7, which is made of polyurethane elastomer, spray-formed on site, seamless, and adaptable to complex curved surfaces. The drainage component is arranged in the elastic cushion layer 7, and a polyurea waterproof coating 8 is sprayed on the outer side of the elastic cushion layer 7.

[0028] The reinforced concrete layer includes a concrete canvas 10, which is connected to the polyurea waterproof coating 8. A circular hole is opened on the concrete canvas 10, in which an anchor rod 6 is arranged. The anchor rod 6 is connected to the drainage component. A steel mesh is hung on the anchor rod 6. After spraying reinforced concrete on the steel mesh, a primary lining concrete 11 is formed, forming a dynamic coupling of rigid support and flexible drainage, realizing the integration of drainage and support structure, and an inspection door 13 is arranged on the reinforced concrete layer. A rubber sealing ring is arranged in the inspection door 13, and a pressure sensor is installed on the inspection door 13.

[0029] The drainage component includes two drainage pipes 2, which are connected by a six-way head 5. One drainage pipe 2 penetrates the six-way head 5 from bottom to top, and the other drainage pipe 2 penetrates the six-way head 5 from right to left. The anchor rod 6 is inserted from the rear end access port of the six-way head 5, and the anchor rod 6 passes through the front end access port of the six-way head 5. A sealing ring 15 is provided at the connection between the six-way head 5 and the drainage pipe 2. The sealing ring 15 is made of medical grade silicone material. The front end access port of the six-way head 5 is provided with a sealing ring 15, and the rear end access port of the six-way head 5 is not provided with a sealing ring 15. The drainage pipe 2 is made of high-density ethylene material. The drainage pipe 2 is connected to the stainless steel bracket 4. A certain sliding space is reserved between the drainage pipe 2 and the stainless steel bracket 4. The drainage pipe 2 is connected to the sand filter pipe 1 through a flexible joint. The drainage pipe 2 has an appearance of a gradient design with a thick bottom and a thin top. The bottom diameter of the drainage pipe 2 is 150 mm, the top diameter of the drainage pipe 2 is 100 mm, and the slope is ≥3%.

[0030] A detachable sand filter assembly is connected to the bottom of the drain pipe 2, and the position of the detachable sand filter assembly matches the position of the inspection door 13. The inspection door 13 is convenient for the staff to regularly inspect and repair the detachable sand filter assembly. The detachable sand filter assembly includes a sand filter tank 9, which is made of stainless steel. A water inlet 17 is arranged at the top of the sand filter tank 9, and the water inlet 17 is connected to the bottom of the drain pipe 2. A quartz sand layer 18 and a gravel layer 16 are arranged in the sand filter tank 9 from top to bottom. The particle size of the quartz sand in the quartz sand layer 18 is 0.5-1mm, and the thickness of the quartz sand layer 18 is 300mm. A filter tube 19 is arranged in the gravel layer 16, and the filter tube 19 is connected to the inside of the sand filter tank 9. A water outlet 20 is connected to the filter tube 19, and the water outlet 20 is connected to the bottom of the sand filter tank 9. The water outlet 20 is connected to the drain ditch 12. Through the primary filtration of the processing assembly and the secondary filtration of the detachable sand filter assembly, the interception efficiency is greater than 95%.

[0031] A construction method for a waterproof and drainage structure in a single-layer lining of a hard rock super-large span cavern, the specific steps are as follows: Step 1: The surrounding rock of the cavern is scanned by geological radar to determine the location, width and seepage amount of the main seepage fissures 14 of the surrounding rock of the cavern, mark the main seepage fissures 14, draw a seepage distribution map, select key areas, install the treatment component at the seepage amount > 5L / min·m, and then drill a hole with a diameter of 250mm and a depth of 2000mm, put the treatment component into the drill hole and connect it to the drainage pipe 2; Step 2: Install the drainage pipe 2 and the anchor rod 6. First, excavate the surrounding rock of the cave, apply a waterproof concrete layer and pre-embed multiple stainless steel brackets 4, connect the drainage pipe 2 with the multiple stainless steel brackets 4, reserve a certain sliding space between the drainage pipe 2 and the stainless steel brackets 4, and then the drainage pipe 2 is formed into a cross shape through the six-way head 5, and the anchor rod 6 passes through the six-way head 5 for grouting. After grouting and fixing, use polyurethane sealant to seal the interface; Step 3: Apply an elastic waterproof cushion layer, spray an elastic cushion layer 7 on the waterproof concrete layer, the thickness of the elastic cushion layer 7 is 15mm, the elongation is ≥500%, and the elastic cushion layer 7 covers the drainage pipe 2 and the first layer of waterproof concrete 3, and then spray a polyurea waterproof coating 8 on the outside of the elastic cushion layer 7, the thickness of the polyurea waterproof coating 8 is 2mm, and the tensile strength is 20MPa; Step 4: a detachable sand filter assembly is arranged every 20 meters along the length direction of the surrounding rock of the cavern, the water inlet 17 at the top of the sand filter tank 9 in the detachable sand filter assembly is connected to the bottom of all the drainage pipes 2 every 20 meters, and the water outlet 20 at the bottom of the sand filter tank 9 is connected to the drainage ditch 12; Step 5: Apply a reinforced concrete layer on the outer layer of the polyurea waterproof coating 8, lay the concrete canvas 10 on the outer layer of the polyurea waterproof coating 8, and then pour water to solidify the concrete canvas 10, pass the anchor rod 6 through the circular hole on the concrete canvas 10 and hang the steel mesh, spray C the first layer of waterproof concrete 30 to reinforce the concrete, and reserve the position of the inspection door 13 in advance when laying the concrete canvas 10 and spraying C the first layer of waterproof concrete 30 to reinforce the concrete.

[0032] Those skilled in the art may make other corresponding changes or deformations to the above technical methods and concepts, and all of these changes or deformations should fall within the protection scope of the claims of the present invention.

Claims

1. A waterproofing and drainage structure in a single-layer lining of a hard rock super-large-span cavern, comprising a cavern surrounding rock, wherein the cavern surrounding rock has a main seepage fissure (14), characterized in that: The waterproof and drainage structure comprises a waterproof concrete layer, an elastic waterproof cushion layer and a reinforced concrete layer which are arranged in sequence from left to right. Before the waterproof concrete layer is applied, the main water seepage cracks (14) are treated first, a treatment component is arranged in the main water seepage cracks (14), a drainage component is arranged in the elastic waterproof cushion layer, and the treatment component is connected to the drainage component; The processing component comprises a sand filter pipe (1), wherein the sand filter pipe (1) is a gravel sand filter pipe, and a gravel layer (16) is arranged inside the sand filter pipe (1); The reinforced concrete layer comprises a concrete canvas (10), the concrete canvas (10) being connected to a polyurea waterproof coating (8), a circular hole being formed on the concrete canvas (10), an anchor rod (6) being arranged in the circular hole, the anchor rod (6) being connected to a drainage assembly, a steel mesh being hung on the anchor rod (6), and a primary lining concrete (11) being formed after reinforced concrete is sprayed on the steel mesh, and an inspection door (13) being arranged on the reinforced concrete layer; The drainage assembly comprises two drainage pipes (2), the two drainage pipes (2) being connected via a six-way head (5), one drainage pipe (2) passing through the six-way head (5) from bottom to top, and the other drainage pipe (2) passing through the six-way head (5) from right to left, the anchor rod (6) being inserted from a rear end access port of the six-way head (5), and the anchor rod (6) passing through a front end access port of the six-way head (5).

2. The waterproof and drainage structure in the single-layer lining of a hard rock super-large span cavern as claimed in claim 1, characterized in that: The waterproof concrete layer comprises a first layer of waterproof concrete (3), the first layer of waterproof concrete (3) being applied on the outside of the cavern surrounding rock, a plurality of stainless steel brackets (4) being pre-embedded in the first layer of waterproof concrete (3) during application, the plurality of stainless steel brackets (4) being evenly distributed along the height direction of the cavern surrounding rock.

3. The waterproof and drainage structure in the single-layer lining of a hard rock super-large span cavern as claimed in claim 2, characterized in that: The elastic waterproof cushion layer comprises an elastic cushion layer (7), the elastic cushion layer (7) is made of polyurethane elastomer, is spray-formed on site, and has seamless joints; the drainage component is arranged in the elastic cushion layer (7), and a polyurea waterproof coating (8) is sprayed on the outer side of the elastic cushion layer (7).

4. The waterproofing and drainage structure in the single-layer lining of a hard rock super-large span cavern as claimed in claim 1, characterized in that: The connection between the six-way head (5) and the drainage pipe (2) is provided with a sealing ring (15); the front end access port of the six-way head (5) is provided with a sealing ring (15); the rear end access port of the six-way head (5) is not provided with a sealing ring (15); the drainage pipe (2) is made of high-density ethylene material; the drainage pipe (2) is connected to a stainless steel bracket (4); and the drainage pipe (2) is connected to a sand filter pipe (1) via a flexible joint.

5. The waterproofing and drainage structure in the single-layer lining of a hard rock super-large span cavern as claimed in claim 1, characterized in that: The drainage pipe (2) has an appearance of a gradient design with a thick bottom and a thin top.

6. The waterproofing and drainage structure in the single-layer lining of a hard rock super-large span cavern as claimed in claim 1, characterized in that: The bottom of the drain pipe (2) is connected to a detachable sand filter assembly, the position of the detachable sand filter assembly matches the position of the inspection door (13), the detachable sand filter assembly comprises a sand filter tank (9), the top of the sand filter tank (9) is provided with a water inlet (17), the water inlet (17) is connected to the bottom of the drain pipe (2), the sand filter tank (9) is provided with a quartz sand layer (18) and a gravel layer (16) from top to bottom, a filter tube (19) is provided in the gravel layer (16), the filter tube (19) is connected to the inside of the sand filter tank (9), the filter tube (19) is connected to a water outlet (20), the water outlet (20) is connected to the bottom of the sand filter tank (9), and the water outlet (20) is connected to a drain ditch (12).

7. A construction method for a waterproof and drainage structure in a single-layer lining of a hard rock super-large span cavern as described in any one of claims 1 to 6, characterized in that: The specific steps are as follows: Step 1: The surrounding rock of the cavern is scanned by geological radar, then cored by drilling, and the treatment component is placed in the borehole; Step 2: Install the drainage pipe (2) and the anchor rod (6), apply a waterproof concrete layer and pre-embed a plurality of stainless steel brackets (4), connect the drainage pipe (2) to the plurality of stainless steel brackets (4), and then connect the drainage pipe (2) to the anchor rod (6) through a six-way connector (5); Step 3: Apply an elastic waterproof cushion layer, spray the elastic cushion layer (7) on the waterproof concrete layer to cover the drainage pipe (2) and the first layer of waterproof concrete (3), and then spray a polyurea waterproof coating (8) on the outside of the elastic cushion layer (7); Step 4: a detachable sand filter assembly is connected at intervals of 20 meters along the length direction of the surrounding rock of the cavern, and the bottoms of all drainage pipes (2) within each interval of 20 meters are connected to the detachable sand filter assembly; Step 5: Apply a reinforced concrete layer on the outer layer of the polyurea waterproof coating (8).

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