Deep drainage system and construction method for fully weathered layer of high water-rich inferior rock

Abstract

The present invention discloses a deep drainage system and construction method for a fully weathered layer of high-water-rich, low-quality rock, comprising a water collection well and a plurality of water suction pipes. The water collection well is arranged to be through-through from top to bottom, and a plurality of first drainage holes are arranged through the side wall of the water collection well. The plurality of first drainage holes are arranged at intervals on the water collection well, and one end of each of the water suction pipes is connected to the corresponding first drainage hole, and the other end is used to be inserted into the low-quality rock layer. The water suction pipes are provided with a plurality of water absorption structures at intervals along their length to absorb the accumulated water in the low-quality rock layer. In the technical solution of the present invention, the water suction holes can absorb water from the fully weathered layer of high-water-rich, low-quality rock into the water suction pipes, and transport the water to the water collection well over a long distance through the water suction pipes, thereby achieving the purpose of increasing the water collection range of the water collection well.

Description

Technical Field

[0001] The present invention relates to the technical field of drainage, and in particular to a deep drainage system for a fully weathered layer of high-water-rich inferior rock and a construction method. Background Art

[0002] The fully weathered layer of inferior rock has the characteristics of uneven weathering, poor self-stabilization ability, large thickness, and uneven water richness. After the rainy season, the fully weathered layer of inferior rock often forms a highly water-rich state. The highly water-rich state of the fully weathered layer of inferior rock will increase the risk of landslides.

[0003] Catchment wells are one of the commonly used methods for landslide control. The purpose of draining groundwater is achieved by setting permeable materials around the catchment wells. However, the drainage range of existing catchment wells is limited and groundwater far away from the catchment well area cannot be drained. Summary of the Invention

[0004] The main purpose of the present invention is to provide a deep drainage system for the fully weathered layer of high-water-rich inferior rock, aiming to provide a water collection well structure and its safe construction method that can achieve large-area drainage of the fully weathered layer of high-water-rich inferior rock.

[0005] To achieve the above-mentioned purpose, the present invention proposes a deep drainage system for fully weathered layers of high-water-rich inferior rock, comprising:

[0006] A water collection well is provided through-through from top to bottom, and a plurality of first drainage holes are provided through-through on the side wall of the water collection well, and the plurality of first drainage holes are arranged at intervals on the water collection well; and

[0007] Multiple water suction pipes, one end of each water suction pipe is connected to the corresponding first drainage hole, and the other end is used to be inserted into the inferior rock formation. Multiple water suction structures are arranged at intervals along the length direction of the water suction pipe to absorb the accumulated water in the inferior rock formation.

[0008] Optionally, the deep drainage system for the fully weathered layer of high-water-rich inferior rock further comprises a capillary water absorption structure, which is provided on the outer surface of the water absorption pipe to absorb the accumulated water in the inferior rock layer and guide the water into the water absorption pipe from the water absorption hole;

[0009] The water absorption structure includes the capillary water absorption structure.

[0010] Optionally, a plurality of the first drainage holes are spaced apart along the depth direction of the water collection well; and / or,

[0011] A plurality of the first drainage holes are spaced apart along the circumferential direction of the water collection well; and / or,

[0012] The first drain hole is arranged to extend obliquely upward, and the angle between the axis of the first drain hole and the horizontal plane is α, and 3°≤α≤7°.

[0013] Optionally, the water collection well includes a plurality of water collection well sections, and an annular positioning protrusion and an annular positioning groove that are plugged into and fit with each other are provided between two adjacent water collection well sections.

[0014] Optionally, each of the water suction pipes includes a plurality of water suction pipe sections connected end to end, and the plurality of water suction pipe sections include an end water suction pipe section connected to the first drain hole, wherein:

[0015] An intermediate connecting joint is provided between adjacent water suction pipe sections; and / or,

[0016] An end connection joint is provided at the end water suction pipe section, and a solid plastic partition is provided in the end connection joint. The solid plastic partition can be pierced under the action of external force to conduct the end water suction pipe section.

[0017] Optionally, a plurality of second drainage holes are provided through the side wall of the water collection well, wherein:

[0018] A plurality of second drainage holes are arranged at intervals along the circumference of the water collection well; and / or,

[0019] A plurality of second drainage holes are spaced apart along the depth direction of the water collection well; and / or,

[0020] In the circumferential direction of the water collection well and / or in the depth direction of the water collection well, the plurality of second drainage holes and the plurality of first drainage holes are alternately arranged; and / or,

[0021] The second drain hole is arranged to extend obliquely upward, and the angle between the axis of the second drain hole and the horizontal plane is β, and 2°≤β≤6°; and / or,

[0022] A first composite geotechnical water-permeable membrane is provided in the second drainage hole, and a nested filter layer is provided on the first composite geotechnical water-permeable membrane.

[0023] Optionally, the deep drainage system of the highly water-rich, inferior rock fully weathered layer further includes a drainage structure, which includes:

[0024] a grit chamber disposed below the water collection well; and

[0025] A drainage pipe has one end connected to the bottom of the water collection well and the other end connected to the inner cavity of the grit chamber.

[0026] Optionally, an anti-seepage layer is provided at the bottom of the water collection well, a first gravel filter layer is provided on the anti-seepage layer, a composite geotextile membrane is provided on the first gravel filter layer, and a second gravel filter layer is provided on the composite geotextile membrane; and / or,

[0027] A manhole cover is provided on the top of the water collection well, a manual through hole is provided on the manhole cover, and a manual inspection cover is provided at the manual through hole; and / or,

[0028] A climbing ladder is provided in the water collection well.

[0029] The present invention also proposes a construction method for a deep drainage system in a fully weathered layer of high-water-rich inferior rock, comprising the following steps:

[0030] S1, prefabricate multiple water collection well sections and multiple water suction pipe sections in the factory;

[0031] S2, excavating the mountain to a first preset depth to form a well pit with a pre-installation space;

[0032] S3, drilling a first pipe hole toward the water-facing side of the mountain in the pre-installation space, and pre-installing a water suction pipe in the first pipe hole;

[0033] S4, hoisting the prefabricated water collection well section into the pre-installation space;

[0034] S5. Continue excavating the mountain below the water collection well section at the first preset depth, so that the installed water collection well section slowly sinks and the pre-installed space is formed again above the water collection well section that has sunk into the pit;

[0035] S6. Repeat the above steps S3 to S5 until all the water collection well sections are placed in the well pit to form a water collection well.

[0036] Optionally, after repeating the above steps S3 to S5 until all the water collection well sections are placed in the well pit, the method further includes:

[0037] S7. Dig a second water hole in the well pit toward the foot of the mountain slope, install a drainage pipe in the second water hole, wrap the drainage pipe inlet with a composite geomembrane, and tie it with 22# galvanized iron wire, with the number of ties being no less than 3;

[0038] S8. Setting a grit chamber at the outlet of the drainage pipe so that the water collection well is connected to the grit chamber;

[0039] S9. Smoothe the bottom of the water collection well with cement mortar and apply waterproof material to form a waterproof layer. Place a bagged sand and gravel filter layer on the waterproof layer to bury the inlet of the drainage pipe. Then lay a composite geomembrane, and continue to lay the bagged sand and gravel filter layer on it.

[0040] S10, filling a third bagged sand and gravel filter layer around the wall of the water collection well and the gaps in the surrounding soil;

[0041] S11, providing an end connection joint at the end of the pre-installed water suction pipe and passing it into the water collection well, and sealing the gap between the water suction pipe and the opening of the well wall of the water collection well with cement mortar;

[0042] S12, puncturing the plastic solid partition in the end connection joint to connect the water suction pipe;

[0043] S13. Install a water collection well cover on the top of the water collection well.

[0044] In the technical solution of the present invention, a plurality of first drainage holes are provided on the side wall of the water collection well, and a plurality of water suction pipes are provided on the water collection well extending from the drainage holes to the surrounding highly water-rich and inferior rock fully weathered layers. The plurality of water suction pipes are provided with a plurality of water suction structures, and the water suction structures can absorb water from the highly water-rich and inferior rock fully weathered layers into the water suction pipes, and transport the water to the water collection well over a long distance through the water suction pipes, so as to achieve the purpose of increasing the water collection range of the water collection well. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0046] Figure 1 A cross-sectional view of an embodiment of a water collection well provided by the present invention;

[0047] Figure 2 for Figure 1 Exploded diagram of each water collection well section;

[0048] Figure 3 for Figure 1 Cross-section of the water collection well;

[0049] Figure 4 for Figure 1 Longitudinal section of the middle suction pipe;

[0050] Figure 5 for Figure 1 Transverse cross-section of the middle suction pipe;

[0051] Figure 6 for Figure 1 Schematic diagram of the structure of the middle protective wall layer;

[0052] Figure 7 for Figure 1 Schematic diagram of the structure of the manhole cover;

[0053] Figure 8 This is a flow chart of a first embodiment of a construction method for a deep drainage system for a fully weathered layer of high-water-rich inferior rock provided by the present invention;

[0054] Figure 9 This is a flow chart of a second embodiment of the construction method of a deep drainage system for a fully weathered layer of high-water-rich inferior rock provided by the present invention.

[0055] Description of Figure Numbers:

[0056]

[0057]

[0058] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0059] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0060] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0061] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0062] The fully weathered layer of inferior rock has the characteristics of uneven weathering, poor self-stabilization ability, large thickness, and uneven water richness. After the rainy season, the fully weathered layer of inferior rock often forms a highly water-rich state. The highly water-rich state of the fully weathered layer of inferior rock will increase the risk of landslides.

[0063] Catchment wells are one of the commonly used methods for landslide control. The purpose of draining groundwater is achieved by setting permeable materials around the catchment wells. However, the drainage range of existing catchment wells is limited and groundwater far away from the catchment well area cannot be drained.

[0064] In order to solve the above problems, the present invention proposes a deep drainage system for high water-rich inferior rock full weathering layer, aiming to provide a water collection well structure and its safe construction method that can achieve large-scale drainage of high water-rich inferior rock along the full weathering layer, wherein, Figures 1 to 7 This is a structural schematic diagram of an embodiment of the deep drainage system for the fully weathered layer of high-water-rich inferior rock provided by the present invention.

[0065] Please refer to Figure 1 The deep drainage system of the highly water-rich, inferior rock fully weathered layer includes a water collection well 1 and multiple water suction pipes 2. The water collection well 1 is arranged to be through-through from top to bottom. The side wall of the water collection well 1 is provided with multiple first drainage holes 11. The multiple first drainage holes 11 are arranged at intervals on the water collection well 1. One end of each of the water suction pipes 2 is connected to the corresponding first drainage hole 11, and the other end is used to be inserted into the inferior rock layer. Multiple water absorption structures are arranged at intervals along the length direction of the water suction pipe 2 to absorb the accumulated water in the inferior rock layer.

[0066] In the technical solution of the present invention, a plurality of first drainage holes 11 are provided on the side wall of the water collection well 1, and a plurality of suction pipes 2 are provided on the water collection well 1 extending from the drainage holes to the surrounding highly water-rich and inferior rock fully weathered layers. The plurality of suction pipes 2 are provided with a plurality of water absorption structures, and the water absorption structures can absorb water from the highly water-rich and inferior rock fully weathered layers into the suction pipes 2, and transport the water to the water collection well 1 over a long distance through the suction pipes 2, so as to achieve the purpose of increasing the water collection range of the water collection well 1.

[0067] The water absorption structure can be a water absorption hole provided on the surface of the water absorption pipe 2, or a capillary structure provided on the surface of the water absorption pipe 2. It can be understood that if water is only absorbed by the water absorption hole on the surface of the water absorption pipe 2, not only the efficiency is slow but also the mud and sand in the inferior rock formation will be introduced into the water absorption pipe 2. Therefore, in one embodiment of the present invention, please refer to Figure 4 and Figure 5 The deep drainage system of the highly water-rich, inferior rock fully weathered layer also includes a capillary water absorption structure 3, which is arranged on the outer surface of the water suction pipe 2 to absorb the accumulated water in the inferior rock layer and guide it into the water suction pipe 2 from the water suction hole. The capillary water absorption structure 3 is located on the surface of the water suction pipe 2, and the accumulated water in the rock layer can be sucked into the water suction pipe 2 through the capillary phenomenon, thereby improving the drainage capacity of the water suction pipe 2 and preventing mud and sand from entering the water suction pipe 2.

[0068] The first drain holes 11 can be spaced apart in multiple directions along the water collection well 1. For example, please refer to Figure 3 In one embodiment of the present invention, a plurality of first drainage holes 11 are arranged at intervals along the depth direction of the water collection well 1, so that the suction pipe 2 can be installed on the water collection well 1 at intervals along the depth direction of the water collection well 1, so that the suction pipe 2 can be distributed in the inferior rock formation along the up and down directions to increase the drainage depth of the water collection well 1. In another embodiment of the present invention, a plurality of first drainage holes 11 are arranged at intervals along the circumferential direction of the water collection well 1, so that the suction pipe 2 can be arranged in the inferior rock formation along the circumference of the water collection well 1 to increase the drainage range of the water collection well.

[0069] Furthermore, in order to allow the accumulated water absorbed by the suction pipe 2 to be discharged into the water collection well 1, in one embodiment of the present invention, the suction pipe 2 is arranged to be inclined upward, specifically, the first drainage hole 11 is extended upward, and the angle between the axis of the first drainage hole 11 and the horizontal plane is α, and 3°≤α≤7°. Preferably, when α=5°, the water collection effect of the water collection well 1 is the best.

[0070] In order to improve construction safety, in one embodiment of the present invention, the water collection well 1 is composed of a plurality of water collection well sections 13. Figure 2The water collection well 1 includes multiple water collection well sections 13, and an annular positioning protrusion 131 and an annular positioning groove 132 that are plugged into each other are provided between two adjacent water collection well sections 13. During the construction process, the mountain can be excavated to a first preset depth to install the water collection well section 13. After the water collection well section 13 is installed, continue to dig down, and allow the installed water collection well section 13 to slowly sink until space for installing another water collection well section 13 is formed above the water collection well section 13 again, and then install another water collection well section 13, and use the annular positioning protrusion 131 and annular positioning groove 132 on the two water collection well sections 13 to connect and position the two water collection well sections 13, and repeat the cycle until the water collection well 1 is formed. The segmented installation of each water collection well section 13 ensures the safety of the water collection well 1 pit excavation, and avoids the risk of collapse of the water collection well 1 pit caused by digging too deep a water collection well 1 pit at one time.

[0071] It is understandable that when digging the first section of the water collection well 1, since the water collection well 1 has not yet sunk, it is impossible to provide good support for the water collection well 1. Therefore, the water collection well 1 is very prone to collapse. Therefore, in order to solve the above problem, please refer to Figure 6 When excavating the first section of the water collection well 1, a protective wall layer 8 is set inside the water collection well 1. Specifically, the protective wall layer 8 includes a steel cage 82 and a concrete layer 81 wrapped on both sides of the steel cage 82. In this way, the water collection well 1 is reinforced to prevent the water collection well 1 from collapsing.

[0072] In order to prevent the installed water collection well from sinking, in one embodiment of the present invention, a third bagged gravel filter layer 9 is filled in the gaps around the well wall and the surrounding soil to keep the well wall and the surrounding soil in a dense state, thereby increasing the friction between the well wall and the surrounding soil and preventing the well wall from sinking.

[0073] It can be understood that in order to achieve a wide range of water absorption in the water collection well 1, the length of the water suction pipe 2 is between 12m and 30m. If the water suction pipe 2 of the said length is processed at one time, it will not only be difficult to process but also difficult to install. Therefore, in order to solve the above problem, in one embodiment of the present invention, each of the water suction pipes 2 includes a plurality of water suction pipe sections 21 connected end to end, and an intermediate connecting joint 22 is provided between adjacent water suction pipe sections 21 to connect the plurality of water suction pipe sections 21 to form the water suction pipe 2, so as to solve the problem of difficulty in processing and installing the excessively long water suction pipe 2. Furthermore, in order to prevent the mud and sand in the soil layer from flowing into the water collection well 1 during the installation of each of the water absorption sections, in another embodiment of the present invention, the multiple water absorption pipe sections 21 include an end water absorption pipe section 211 for connecting to the first drainage hole 11, and the end water absorption pipe section 211 is provided with an end connecting joint 23, and a solid plastic partition 24 is provided in the end connecting joint 23. The solid plastic partition 24 can isolate the passage from each of the water absorption pipe sections 21 to the water collection well 1, thereby preventing the mud and sand from flowing into the water collection well 1 during the installation of the water collection pipe sections. After the installation of each of the water collection pipe sections is completed, the solid plastic partition 24 can be pierced by external force to connect the end water absorption pipe section 211 and the water collection well 1.

[0074] In order to achieve drainage of nearby rock formations by the water collection well 1, in one embodiment of the present invention, a plurality of second drainage holes 12 are provided on the side wall of the water collection well 1, and similar to the first drainage holes 11, each of the second drainage holes 12 can be arranged at intervals along the circumference of the water collection well 1 to increase the drainage range of the water collection well 1 for the surrounding inferior rock formations, and each of the second drainage holes 12 can also be arranged at intervals along the depth direction of the water collection well 1 to increase the drainage depth of the water collection well 1 for the surrounding inferior rock formations. Furthermore, in the circumference of the water collection well 1 and / or in the depth direction of the water collection well 1, a plurality of the second drainage holes 12 and a plurality of the first drainage holes 11 are alternately arranged at intervals, so as to reasonably arrange the distribution of the first drainage holes 11 and the second drainage holes 12 in the inferior rock formations, thereby improving the drainage efficiency of the water collection well 1.

[0075] Furthermore, in order to allow the accumulated water in the inferior rock formations around the water collection well 1 to be introduced into the water collection well 1, the second drainage hole 12 is arranged to extend upward at an angle, and the angle between the axis of the second drainage hole 12 and the horizontal plane is β, and 2°≤β≤6°. Preferably, when β=5°, the water collection effect of the water collection well 1 is the best.

[0076] In order to prevent sediment from entering the water collection well 1 through the second drainage hole 12, in one embodiment of the present invention, a first composite geotextile membrane 53 is provided in the second drainage hole 12, and a nested filter layer is provided on the first composite geotextile membrane 53. The nested filter layer can be penetrated by water but cannot be penetrated by sediment, thereby preventing sediment in the inferior layer from entering the water collection well 1 through the second drainage hole 12.

[0077] In order to drain the accumulated water in the water collection well 1, in one embodiment of the present invention, the water collection well 1 is also provided with a drainage structure 4. Specifically, the drainage structure 4 includes a grit chamber 41 and a drainage pipe 42. The grit chamber 41 is arranged lower than the water collection well 1. One end of the drainage pipe 42 is connected to the bottom of the water collection well 1, and the other end is connected to the inner cavity of the grit chamber 41. In this way, the accumulated water in the water collection well 1 can be discharged into the grit chamber 41 through the drainage hole.

[0078] In order to prevent water seepage at the bottom of the water collection well 1, in one embodiment of the present invention, a waterproof structure 5 is provided at the bottom of the water collection well 1, and the waterproof structure 5 includes an anti-seepage layer 51 and a first gravel filter layer 52 and a composite geotextile waterproof membrane 53 provided on the anti-seepage layer 51. Specifically, the anti-seepage layer 51 is provided at the bottom of the water collection well 1, and the anti-seepage layer 51 is mainly composed of cement mortar and other waterproof materials. A first gravel filter layer 52 is provided on the anti-seepage layer 51, a composite geotextile waterproof membrane 53 is provided on the first gravel filter layer 52, and a second gravel filter layer 54 is provided on the composite geotextile waterproof membrane 53. The gravel of the first gravel filter layer 52 and the second gravel filter layer 54 has a gravel particle size of less than 0.15 mm and a particle content of less than 5%. In this way, the first gravel filter layer 52 and the second gravel filter layer 54 have good water resistance and weathering resistance.

[0079] To prevent pedestrians or debris from falling into the water collection well 1, please refer to Figure 1 and Figure 7 A manhole cover 6 is provided on the top of the water collection well 1, and an artificial passage hole is provided on the manhole cover 6. In order to facilitate subsequent inspection and maintenance of the water collection well 1, a manual inspection cover 61 is provided at the artificial passage hole. At the same time, a climbing ladder 7 is provided inside the water collection well 1 to facilitate construction personnel to carry out maintenance and inspection work on the water collection well 1 at any time.

[0080] The present invention also proposes a construction method for a deep drainage system in a fully weathered layer of high-water-rich inferior rock. Figure 8 , Figure 8This is a flow chart of a first embodiment of a construction method for a deep drainage system for a fully weathered layer of high-water-rich inferior rock provided by the present invention. The construction method for a deep drainage system for a fully weathered layer of high-water-rich inferior rock includes the following steps:

[0081] S1. Prefabricate multiple water collection well sections and multiple water suction pipe sections in the factory.

[0082] Understandably, if the suction pipe section is too long, machining will be difficult, while if it is too short, construction will be slow. Therefore, in one embodiment of the present invention, the length of a single suction pipe section is set to 1 meter. Furthermore, the size of the water collection well section should not be too small or too large. From a cost and drainage perspective, in one embodiment of the present invention, the outer diameter of the water collection well section is set to 4 meters, the inner diameter is set to 3 meters, and the height is set to 2 meters. The first and second drainage holes in the water collection well have a diameter of 100 mm and an elevation angle of 5 degrees.

[0083] S2. Excavating the mountain to a first preset depth to form a well pit with a pre-installation space.

[0084] It can be understood that if the first preset depth is too deep, the risk of excavation collapse will increase, and if the first preset depth is too shallow, the construction efficiency will be too low. Therefore, in one embodiment of the present invention, the preset depth is 2m to adapt to the depth of the water collection well section. Excavation is stopped after digging 2 meters until the water collection well section is hoisted and then continues to dig 2m.

[0085] At the same time, after the first section of the pit is formed, in order to prevent the pit from collapsing due to lack of support, in another embodiment of the present invention, a protective wall layer is provided around the pit, and the protective wall layer includes a steel cage and a concrete layer covering the steel cage. In this way, the purpose of reinforcing the pit is achieved and the pit is prevented from collapsing.

[0086] S3. Digging a first pipe hole toward the water-facing side of the mountain in the pre-installation space, and pre-installing a water suction pipe in the first pipe hole.

[0087] In the above steps, if the depth of the first pipe hole is too long, it will make the installation of the water suction pipe section difficult; if it is too short, it will affect the drainage efficiency of the water collection well. Therefore, in one embodiment of the present invention, the aperture of the first pipe hole is set to 100 mm and the elevation angle is set to 5° to adapt to the water suction pipe section. The length of the first pipe hole is set between 12m and 30m. In this way, while ensuring the convenience of installation of the water suction pipe section, the drainage effect of the water collection well is guaranteed.

[0088] S4. Hoisting the prefabricated water collection well section into the pre-installation space.

[0089] S5. Continue excavating the mountain below the water collection well section at the first preset depth, so that the installed water collection well section slowly sinks, and the pre-installation space is formed again above the water collection well section that has fallen into the pit.

[0090] S6. Repeat the above steps S3 to S5 until all the water collection well sections are placed in the well pit to form a water collection well.

[0091] In the above steps, when the excavation depth exceeds 10m, construction workers must first use a blower to force air or oxygen into the hole through an air pipe before descending. Operators must work within 2m of the air outlet. During operations, hazardous gases and oxygen levels in the hole must be tested every two hours. Two sets of isolated oxygen-concentrating self-rescuers are required on-site to meet rescue needs. When the excavation depth exceeds 15m, workers must carry a walkie-talkie, and workers must not work continuously in the hole for more than two hours.

[0092] In the above embodiment, multiple water collection well sections and multiple water suction pipes are prefabricated in the factory, and a well pit is dug in the fully weathered layer of high-water-rich inferior rock that needs to be drained to form a pre-installation space, and reinforcement measures are taken. Then, a first pipe hole is dug towards the water-facing side of the mountain in the pre-installation space, and a water suction pipe is pre-installed in the first pipe hole; after the installation of the water suction pipe is completed, the water collection well section is hoisted into the pre-installation space, and downward digging is continued to allow the water collection well section to slowly sink until the next pre-installation space is formed, and the next water collection well section is continued to be hoisted, and the two water collection well sections are connected and positioned through the annular positioning protrusions and annular positioning grooves on the water collection well section, and the cycle is repeated until all the water collection well sections are spliced ​​together, so as to realize the construction and installation of the water collection well in the fully weathered layer of high-water-rich inferior rock.

[0093] Please refer to Figure 9 , Figure 9 This is a flow chart of a second embodiment of the construction method of a deep drainage system for a fully weathered layer of high-water-rich inferior rock provided by the present invention. After repeating the above steps S3 to S5 until all the water collection well sections are placed in the well pit, the method further includes:

[0094] S7. Dig a second water hole in the well pit toward the foot of the mountain slope, install a drainage pipe in the second water hole, wrap the drainage pipe inlet with a composite geomembrane, and use 22# galvanized iron wire to tie it, with the number of tying circles not less than 3.

[0095] In the above steps, the inlet of the drainage pipe is wrapped with a composite geotextile membrane to prevent mud and sand from entering the drainage pipe, thereby causing blockage of the drainage pipe. At the same time, the composite geotextile membrane is tied with 22# galvanized iron wire, and the number of tying circles is not less than 3 circles to ensure the firmness of the bundling of the composite geotextile membrane. At the same time, the iron wire is 22# galvanized, which can effectively prevent the iron wire from rusting and rotting.

[0096] S8. A grit chamber is provided at the outlet of the drainage pipe so that the water collection well is connected to the grit chamber.

[0097] In the above steps, a grit chamber is set at the outlet of the drainage pipe, and the water collection well is connected to the grit chamber through the drainage pipe, so that the accumulated water in the water collection well can enter the grit chamber through the drainage pipe. The grit chamber can effectively filter out large particles of sand and gravel in the accumulated water, thereby realizing the filtration and preliminary treatment of the accumulated water.

[0098] S9. The bottom of the water collection well is smoothed with cement mortar and coated with waterproof material to form a waterproof layer. A bagged sand and gravel filter layer is placed on the waterproof layer to bury the inlet of the drainage pipe. A composite geomembrane is then laid, and a bagged sand and gravel filter layer is continued to be laid thereon.

[0099] In the above steps, in order to prevent the accumulated water in the inferior layer from penetrating into the water collection well and causing the water collection well to sink, the bottom of the water collection well is coated with waterproof material. At the same time, in order to facilitate the coating of waterproof material, the bottom of the water collection well is leveled with cement mortar. Cement mortar also has a certain preventive effect on water seepage. In order to further prevent the grinding wheel from entering the drain pipe, a bagged gravel filter layer is placed on the waterproof layer. A composite geotextile permeable membrane is laid on the bagged gravel filter layer. The drain pipe is buried under the bagged gravel filter layer to prevent sand and gravel from entering the drain pipe. Furthermore, the gravel particle size of the bagged gravel filter layer is less than 0.15 mm, and the particle content is less than 5%. In this way, the first gravel filter layer and the second gravel filter layer have good water resistance and weathering resistance.

[0100] S10, filling a third bagged sand and gravel filter layer around the well wall of the water collection well and the gaps in the surrounding soil.

[0101] In the above step, the gaps around the well wall and the surrounding soil are filled with bagged sand and gravel filter layers to keep the well wall and the surrounding soil in a dense state, thereby preventing the well wall from sinking.

[0102] S11. An end connection joint is provided at the end of the pre-installed water suction pipe, and the pipe is passed into the water collection well. The gap between the water suction pipe and the opening of the well wall of the water collection well is sealed with cement mortar.

[0103] In the above steps, in order to prevent mud and sand from entering the water collection well through the water suction pipe section during installation, a plastic solid partition is provided in the water suction pipe, and at the same time, the gaps between the openings in the wall of the water collection well are sealed with cement mortar to prevent mud and sand from penetrating inward during construction.

[0104] S12, puncturing the plastic solid partition in the end connection joint to connect the water suction pipe.

[0105] S13. Install a water collection well cover on the top of the water collection well.

[0106] In the above steps, in order to prevent pedestrians from falling into the water collection well and to prevent dust from entering the water collection well, a ductile iron manhole cover with a diameter of 70 mm is installed on the top of the water collection well, and a manual inspection cover is installed on the manhole cover. The position of the manual inspection cover corresponds to the position of the climbing ladder to facilitate construction personnel to enter the water collection well through the manual inspection cover.

[0107] In the above embodiment, in order to prevent water seepage from the bottom of the water collection well, a waterproof layer, a bagged gravel filter layer and a composite geotextile membrane are provided at the bottom of the water collection well, and the bagged gravel filter layer and the composite geotextile membrane are covered on top of the drainage pipe to prevent mud and sand from entering the drainage pipe. At the same time, the drainage pipe mouth is tied with a composite geotextile membrane through 22# galvanized iron wire to further prevent mud and sand from penetrating into the drainage pipe. In order to prevent mud and sand from entering the water collection well through the orifice of the water collection well during the construction of the water collection well, a solid plastic plate is provided in the water suction pipe section. In the water collection well, the gap between the water suction pipe and the opening of the well wall of the water collection well is sealed with cement mortar, so as to prevent mud and sand from entering the water collection well during the construction of the water collection well, thereby hindering the construction.

[0108] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A construction method for a deep drainage system in a fully weathered layer of high-water-rich inferior rock, characterized in that: The steps include: S1, prefabricate multiple water collection well sections and multiple water suction pipe sections in the factory; S2, excavating the mountain to a first preset depth to form a well pit with a pre-installation space; S3, drilling a first pipe hole toward the water-facing side of the mountain in the pre-installation space, and pre-installing a water suction pipe in the first pipe hole; S4, hoisting the prefabricated water collection well section into the pre-installation space; S5. Continue excavating the mountain below the water collection well section at the first preset depth, so that the installed water collection well section slowly sinks and the pre-installed space is formed again above the water collection well section that has sunk into the pit; S6, repeating the above steps S3 to S5 until all the water collection well sections are placed in the well pit to form a water collection well; The deep drainage system of the fully weathered layer of high water-rich inferior rock includes: A water collection well is provided through-through from top to bottom, and a plurality of first drainage holes are provided through-through on the side wall of the water collection well, and the plurality of first drainage holes are arranged at intervals on the water collection well; and a plurality of water suction pipes, one end of each of the water suction pipes being connected to the corresponding first drain hole, and the other end being inserted into the inferior rock formation, wherein the water suction pipes are provided with a plurality of water suction structures spaced apart along the length thereof for absorbing the accumulated water in the inferior rock formation; The side wall of the water collection well is provided with a plurality of second drainage holes, wherein: A plurality of second drainage holes are arranged at intervals along the circumference of the water collection well; and / or, A plurality of second drainage holes are spaced apart along the depth direction of the water collection well; and / or, In the circumferential direction of the water collection well and / or in the depth direction of the water collection well, the plurality of second drainage holes and the plurality of first drainage holes are alternately arranged; and / or, The second drain hole is arranged to extend obliquely upward, and the angle between the axis of the second drain hole and the horizontal plane is β, and 2°≤β≤6°; and / or, A first composite geotechnical water-permeable membrane is provided in the second drainage hole, and a nested filter layer is provided on the first composite geotechnical water-permeable membrane; An anti-seepage layer is provided at the bottom of the water collection well, a first gravel filter layer is provided on the anti-seepage layer, a composite geotextile membrane is provided on the first gravel filter layer, and a second gravel filter layer is provided on the composite geotextile membrane; and / or, A manhole cover is provided on the top of the water collection well, a manual through hole is provided on the manhole cover, and a manual inspection cover is provided at the manual through hole; and / or, A climbing ladder is provided in the water collection well.

2. The construction method of the deep drainage system of the fully weathered layer of high water-rich inferior rock according to claim 1 is characterized in that: After repeating the above steps S3 to S5 until all the water collection well sections are placed in the well pit, the method further includes: S7. Dig a second water hole in the well pit toward the foot of the mountain slope, install a drainage pipe in the second water hole, wrap the drainage pipe inlet with a composite geomembrane, and tie it with 22# galvanized iron wire, with the number of ties being no less than 3; S8. Setting a grit chamber at the outlet of the drainage pipe so that the water collection well is connected to the grit chamber; S9. Smoothe the bottom of the water collection well with cement mortar and apply waterproof material to form a waterproof layer. Place a bagged sand and gravel filter layer on the waterproof layer to bury the inlet of the drainage pipe. Then lay a composite geomembrane, and continue to lay the bagged sand and gravel filter layer on it. S10, filling a third bagged sand and gravel filter layer around the wall of the water collection well and the gaps in the surrounding soil; S11, providing an end connection joint at the end of the pre-installed water suction pipe and passing it into the water collection well, and sealing the gap between the water suction pipe and the opening of the well wall of the water collection well with cement mortar; S12, puncturing the plastic solid partition in the end connection joint to connect the water suction pipe; S13. Install a water collection well cover on the top of the water collection well.

3. The construction method of the deep drainage system of the fully weathered layer of high water-rich inferior rock according to claim 1 is characterized in that: The deep drainage system for the fully weathered layer of high-water-rich inferior rock also includes a capillary water absorption structure, which is arranged on the outer surface of the water absorption pipe to absorb the accumulated water in the inferior rock layer and guide it into the water absorption pipe through the water absorption hole; The water absorption structure includes the capillary water absorption structure.

4. The construction method of the deep drainage system of the fully weathered layer of high water-rich inferior rock according to claim 1 is characterized in that: A plurality of the first drainage holes are spaced apart along the depth direction of the water collection well; and / or, A plurality of the first drainage holes are spaced apart along the circumferential direction of the water collection well; and / or, The first drain hole is arranged to extend obliquely upward, and the angle between the axis of the first drain hole and the horizontal plane is α, and 3°≤α≤7°.

5. The construction method of the deep drainage system of the fully weathered layer of high water-rich inferior rock according to claim 1 is characterized in that: The water collection well comprises a plurality of water collection well sections, and an annular positioning protrusion and an annular positioning groove which are plugged into and matched with each other are provided between two adjacent water collection well sections.

6. The construction method of the deep drainage system of the fully weathered layer of high water-rich inferior rock according to claim 1 is characterized in that: Each of the water suction pipes includes a plurality of water suction pipe sections connected end to end, and the plurality of water suction pipe sections include an end water suction pipe section for connecting to the first drain hole, wherein: An intermediate connecting joint is provided between adjacent water suction pipe sections; and / or, An end connection joint is provided at the end water suction pipe section, and a solid plastic partition is provided in the end connection joint. The solid plastic partition can be pierced under the action of external force to conduct the end water suction pipe section.

7. The construction method of the deep drainage system of the fully weathered layer of high water-rich inferior rock according to claim 1 is characterized in that: The deep drainage system of the highly water-rich inferior rock fully weathered layer also includes a drainage structure, which includes: a grit chamber disposed below the water collection well; and A drainage pipe has one end connected to the bottom of the water collection well and the other end connected to the inner cavity of the grit chamber.

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