Construction method of drainage pipe for slope support

Abstract

This invention discloses a construction method for a drainage pipe for slope support, comprising the following steps: 1. According to the location of the drainage pipe as shown in the construction drawings, move the drilling rig to position; 2. Insert a section of the drainage pipe body into the drill bit and fix it with a jacking component; 3. Start the drilling rig and allow the drill bit to drill in, storing the drill cuttings in the soil chamber of the drill bit; 4. When the drill bit reaches a certain depth, stop drilling and extend the drill bit using a detachable drill rod (3); 5. Insert the next section of the drainage pipe body coaxially into the detachable drill rod, and connect the next section of the drainage pipe body coaxially with the previous section of the drainage pipe body, while the drilling rig continues to control the drill bit to drill in; 6. Repeat steps 4 and 5 until the depth of the borehole is greater than the design depth; 7. Inject fine sand into the borehole and retract the drill rod to bury the drainage pipe body inside the borehole. This invention can assist in the installation of the drainage pipe, does not damage the non-woven fabric wrapped around the drainage pipe during installation, and makes the drainage pipe less prone to clogging during use.

Description

Technical Field

[0001] The invention relates to a slope support construction method, in particular to a slope support drainage pipe construction method. Background Art

[0002] As the design height of building structures becomes higher and higher, the depth of the underground part of the building structure is also getting deeper and deeper. During the construction of the foundation pit, the safety of the slope support is very important. Since water damage is fatal to the stability of the slope structure, drainage pipes are usually installed on the slope support during slope support. The drainage pipes can be used to timely drain the water in the soil after the slope support to avoid the impact of water damage and increase the stability of the slope support.

[0003] The construction method of drain pipes in the prior art is: first, use a drilling rig to drill a hole at the designed installation position of the drain pipe, use a PVC pipe with a hole as the main body of the drain pipe, and then insert the PVC pipe wrapped with non-woven fabric into the drilled hole to play the role of draining water, thus completing the installation of the drain pipe. The construction method of drain pipes in the prior art has the following shortcomings:

[0004] 1. When the drainage pipe is inserted into the drilled hole, the non-woven fabric wrapped on the outside is easily damaged by friction with the hole wall, resulting in a sharp decline in the drainage effect of the drainage pipe. It may even cause the holes of the PVC pipe to be blocked by the soil and unable to effectively drain the water in the soil, affecting the support safety of the slope.

[0005] 2. After the drainage pipe is installed, since the non-woven fabric is in direct contact with the soil, the soil can easily block the pores of the non-woven fabric, reducing the drainage effect and affecting the support safety of the slope.

[0006] Therefore, it is necessary to provide a construction method for a drainage pipe which does not damage the nonwoven fabric during installation and reduces clogging during use. Summary of the invention

[0007] The purpose of the present invention is to provide a construction method for a slope support drain pipe, which can assist in the installation of the drain pipe without damaging the non-woven fabric wrapped around the outside of the drain pipe during installation, and the drain pipe is not easily blocked during use.

[0008] The present invention is achieved in that:

[0009] A construction method for a slope support drain pipe comprises the following steps:

[0010] Step 1: Move the drilling rig into position according to the location of the drainage pipe laid out in the construction drawing;

[0011] Step 2: Insert a section of the drain pipe into the drill bit and fix it with the jacking assembly;

[0012] Step 3: Start the drilling machine, make the drill bit drill, and the drill cuttings are stored in the soil bin of the drill bit;

[0013] Step 4: When the drill bit reaches a certain depth, stop drilling and extend the drill bit through the detachable drill rod;

[0014] Step 5: Insert the next drain pipe body coaxially into the detachable drill pipe, and the next drain pipe body is coaxially plugged with the previous drain pipe body, and the drilling rig continues to control the drill bit to drill;

[0015] Step 6: Repeat steps 4 and 5 until the drilling depth is greater than the designed depth;

[0016] Step 7: Inject fine sand into the borehole and retract the drill rod so that the main body of the drain pipe is buried and installed inside the borehole.

[0017] The drill bit comprises a fixed drill rod and a fixed drill bit, the head of the fixed drill rod is a conical structure, and the small head end of the conical structure is coaxially connected to the fixed drill bit, the tail of the fixed drill rod is a cylindrical structure, the large head end of the conical structure is connected to the head end of the cylindrical structure, and the tail end of the cylindrical structure is connected to the output end of the drilling rig;

[0018] The conical structure of the fixed drill rod is composed of a plurality of triangular arc panels, and the plurality of triangular arc panels can be installed at the head end of the cylindrical structure of the fixed drill rod in an openable manner.

[0019] The drill bit also includes a detachable drill rod, which is a cylindrical structure. The detachable drill rod can be detachably coaxially connected to the tail end of the fixed drill rod cylindrical structure through an active buckle, and two adjacent sections of the detachable drill rod can be detachably coaxially connected through an active buckle.

[0020] The fixed drill rod is a double-layer structure consisting of an outer wall of the drill rod and an inner wall of the drill rod, and the cavity between the outer wall of the drill rod and the inner wall of the drill rod forms a soil bin; the drain pipe body is coaxially inserted into the inner wall of the drill rod of the cylindrical structure of the fixed drill rod through a jacking assembly;

[0021] The detachable drill rod is a double-layer structure consisting of an outer wall and an inner wall of the drill rod. The cavity between the outer wall and the inner wall of the drill rod forms a soil bin, and the soil bin in the detachable drill rod is connected with the soil bin in the fixed drill rod. The drain pipe body is coaxially inserted into the inner wall of the drill rod of the detachable drill rod. A water pipe is arranged in the soil bin of the detachable drill rod, and the water pipes in two adjacent sections of the detachable drill rod can be connected in sequence and connected with the water pipe in the fixed drill rod.

[0022] The drain pipe body comprises a drain pipe, a first filter layer, a second filter layer and a third filter layer; a plurality of drain holes are formed at intervals on the drain pipe, the first filter layer is wrapped on the drain pipe, the second filter layer is wrapped on the first filter layer, and the third filter layer is wrapped on the second filter layer.

[0023] The drain pipe is a PVC pipe, the first filter layer and the third filter layer are non-woven fabrics, and the second filter layer is graded gravel;

[0024] The outer diameter of the drain pipe body is smaller than the inner diameter of the cylindrical structure of the fixed drill rod of the drill bit, so that the drain pipe body can be coaxially inserted into the fixed drill rod; the length of each section of the drain pipe body is consistent with the length of the cylindrical structure of the fixed drill rod;

[0025] The outer diameter of the drain pipe body is smaller than the inner diameter of the detachable drill rod of the drill bit, so that the drain pipe body can be coaxially inserted into the detachable drill rod, and the length of the drain pipe body is consistent with the length of the detachable drill rod;

[0026] A connecting portion is formed at the end of the drain pipe, so that two adjacent drain pipe sections can be detachably coaxially connected through the connecting portion.

[0027] The pushing assembly is arranged in the conical structure of the fixed drill rod, and the pushing assembly includes a top plate and a push rod; one surface of the top plate is fitted and connected to one end of the drain pipe body close to the fixed drill bit, one end of the push rod is coaxially and vertically connected to the top plate, and the other end of the push rod is coaxially pressed at the small head end of the conical structure and is rotatably connected to the fixed drill bit through a ball shaft.

[0028] The fixed drill rod is provided with a movable cover plate, which can be opened and closed and connected to the soil bin. A water pipe is provided in the soil bin of the drill bit, and the water pipe is connected to a high-pressure water source. When the movable cover plate is opened, high-pressure water is transported into the soil bin through the water pipe by an external high-pressure water source to flush the drill cuttings out of the soil bin from the movable cover plate.

[0029] During the drilling process of the drill bit, when the pressure in the soil bin of the drill bit reaches the standard pressure, the drilling is suspended, and the drilling is continued after the drilling debris in the soil bin of the drill bit is cleaned;

[0030] During the process of the drill bit continuing to drill, when the standard pressure is reached in the soil bin of the drill bit, the drilling is suspended, and the drilling is continued after the drill residue in the soil bin of the drill bit is cleaned.

[0031] The step 7 comprises the following sub-steps:

[0032] Step 7.1: The fixed drill pipe includes a conical structure and a cylindrical structure, and the conical structure includes a plurality of triangular arc panels; the drill bit is pulled back for a distance, and the triangular arc panels of the conical structure of the fixed drill pipe are opened and parallel to the cylindrical structure through the controller of the drilling rig, and the jacking assembly is coaxially inserted into the borehole, and one end of the drain pipe body is fixed in the borehole through the jacking assembly;

[0033] Step 7.2: A water pipe is provided in the soil bin, and the water pipe is connected to a sand supply mechanism to inject fine sand into the borehole;

[0034] Step 7.3: Continue to pull back the drill bit and inject fine sand until the drill bit is completely out of the borehole, bury the drain pipe body inside the borehole, and fill the gap between the drain pipe body and the hole wall with fine sand;

[0035] Step 7.4: Seal the outer surface of the gap between the drain pipe body and the drilled hole.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. In the present invention, the drain pipe body is inserted into the fixed drill bit and the detachable drill rod, and the drain pipe body is synchronously pushed into the borehole as the drill bit drills. The drain pipe body does not contact the hole wall during installation, thus avoiding the problems of damage caused by friction between the non-woven fabric and the hole wall and clogging of the pores by the soil when the drain pipe is inserted into the borehole in the prior art, thereby ensuring the installation reliability of the drain pipe body and the effectiveness of draining water from the soil.

[0038] 2. The present invention adopts a detachable drill rod to extend the drill bit section by section, and inserts the drain pipe body into the detachable drill rod section by section along with the extension connection of the detachable drill rod, thereby realizing the segmented installation of the drain pipe body through segmented drilling, and simultaneously performing slag cleaning operation during the drilling process, which is beneficial to improving the construction efficiency, construction quality and construction safety of the drain pipe body, and reduces the difficulty of installation construction for a drain pipe body with a longer length.

[0039] 3. The drain pipe body of the present invention uses non-woven fabric to wrap the PVC pipe, and the graded sand and gravel are wrapped on the outside of the PVC pipe by the non-woven fabric, thereby ensuring a good filtering effect. At the same time, fine sand is filled in the gap between the drain pipe body and the borehole wall to form an isolation between the third filter layer and the hole wall, effectively avoiding the blockage of the non-woven fabric pores by soil, ensuring the drainage function of the drain pipe body and reducing the number of maintenance times during the use of the drain pipe body.

[0040] 4. The invention has simple construction process, is easy to operate, is convenient to assemble and disassemble, has low construction cost, can be widely used in foundation pit slope support construction, and has good prospects for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of a drill bit in the construction method of the slope support drain pipe of the present invention;

[0042] Figure 2 It is an axial cross-sectional view of a drill bit in the construction method of the slope support drain pipe of the present invention;

[0043] Figure 3 It is a radial cross-sectional view of a detachable drill rod in the construction method of the slope support drain pipe of the present invention.

[0044] In the figure, 1 is a fixed drill rod, 2 is a fixed drill bit, 3 is a detachable drill rod, 4 is a movable buckle, 5 is a drain pipe, 6 is a first filter layer, 7 is a second filter layer, 8 is a third filter layer, 9 is a movable cover plate, 10 is a water pipe, 11 is an outer wall of the drill rod, 12 is an inner wall of the drill rod, 13 is a top plate, 14 is a top rod, and 15 is a slag inlet hole. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0046] A construction method for a slope support drain pipe comprises the following steps:

[0047] Step 1: According to the location of the drain pipe laid out on the construction drawing, mark the hole position, and move the drilling rig (not shown in the figure) into position so that the drill bit of the drilling rig can be aligned with the hole position mark.

[0048] Please see attached Figure 1 and attached Figure 2 The drill bit includes a fixed drill rod 1 and a fixed drill bit 2. The head of the fixed drill rod 1 is a conical structure, and the small head end of the conical structure is coaxially connected to the fixed drill bit 2. The tail of the fixed drill rod 1 is a cylindrical structure, the large head end of the conical structure is connected to the head end of the cylindrical structure, and the tail end of the cylindrical structure is connected to the output end of the drilling rig.

[0049] After the drilling rig is powered on, the controller of the drilling rig controls the fixed drill rod 1 and the fixed drill bit 2 to rotate, and a hole is drilled on the support surface through the conical structure of the fixed drill bit 2 and the fixed drill rod 1.

[0050] The conical structure of the fixed drill rod 1 is composed of a plurality of triangular arc panels, which can be installed at the head end of the cylindrical structure of the fixed drill rod 1 in an openable manner.

[0051] The triangular arc panels can be connected by hinges, which can be easily opened and closed by the controller of the drilling rig. When the triangular arc panels are opened, they are located in the same annular surface as the cylindrical structure, so as to facilitate the withdrawal of the drill bit. When the triangular arc panels are closed, they can be spliced ​​to form a conical structure, which is convenient for the drill bit to drill in. The openable structure of the drill bit is a conventional structure of the drill bit of the drilling rig, which enables it to realize the drilling and withdrawal functions, and will not be repeated here.

[0052] Step 2: Insert a section of drain pipe into the drill bit and secure it with the jacking assembly.

[0053] Please see attached Figure 2 and attached Figure 3The drain pipe body includes a drain pipe 5, a first filter layer 6, a second filter layer 7 and a third filter layer 8; a plurality of drain holes (not shown in the figure) are formed at intervals on the drain pipe 5, the first filter layer 6 is wrapped on the drain pipe 5, the second filter layer 7 is wrapped on the first filter layer 6, and the third filter layer 8 is wrapped on the second filter layer.

[0054] The drainage pipe 5 with drainage holes can be used to drain water in the slope soil. The drainage holes are prevented from being blocked by triple filtration through the first filter layer 6, the second filter layer 7 and the third filter layer 8, thereby ensuring smooth drainage.

[0055] Preferably, the drain pipe 5 can be a PVC pipe.

[0056] Preferably, the first filter layer 6 and the third filter layer 8 may be made of non-woven fabric.

[0057] Preferably, the second filter layer 7 may be made of graded gravel, the particle size of which may be selected according to the actual construction environment to ensure effective filtering and drainage effects, and the graded gravel may be wrapped by the third filter layer 8 to ensure that the graded gravel will not fall off.

[0058] The outer diameter of the drain pipe body is slightly smaller than the inner diameter of the cylindrical structure of the fixed drill rod 1 of the drill bit, so that the drain pipe body can be coaxially inserted into the fixed drill rod 1; the length of each section of the drain pipe body is consistent with the length of the cylindrical structure of the fixed drill rod 1.

[0059] When the drain pipe body is inserted into the fixed drill rod 1, the coaxiality between the drain pipe body and the fixed drill rod 1 can be ensured to avoid deviation, thereby ensuring the coaxiality of each section of the drain pipe body after being sleeved in sequence. Since the tail end of the fixed drill rod 1 needs to be connected to the output end of the drilling rig, the drain pipe body is not exposed after being inserted into the cylindrical structure of the fixed drill rod 1, avoiding interference with the connection between the fixed drill rod 1 and the drilling rig.

[0060] The pushing assembly is arranged in the conical structure of the fixed drill rod 1, and the pushing assembly includes a top plate 13 and a push rod 14; one surface of the top plate 13 is fitted and connected to one end of the drain pipe body close to the fixed drill bit 2, one end of the push rod 14 is coaxially and vertically connected to the top plate 13, and the other end of the push rod 14 is coaxially pressed at the small head end of the conical structure and rotatably connected to the fixed drill bit 2 through a ball shaft, so that the thrust of the push rod 14 is guaranteed to be pushed forward during the rotation drilling of the fixed drill bit 2 relative to the push rod through the ball shaft.

[0061] By setting the jacking assembly, it is convenient to fix the drain pipe body in the cylindrical structure of the fixed drill rod 1, and ensure the coaxiality of the drain pipe body and the fixed drill rod 1, and also ensure that the drain pipe body can be pushed forward synchronously with the drilling of the drill bit.

[0062] Step 3: Start the drilling rig and allow the drill to drill slowly. The drill residue is stored in the soil bin of the drill. The drilling speed of the drill is determined according to the geological conditions.

[0063] The fixed drill rod 1 is a double-layer structure consisting of a drill rod outer wall 11 and a drill rod inner wall 12. The cavity between the drill rod outer wall 11 and the drill rod inner wall 12 forms a soil bin; the drain pipe body is coaxially inserted into the drill rod inner wall 12 of the cylindrical structure of the fixed drill rod 1 through a jacking assembly. A slag inlet hole 15 connected to the soil bin is reserved at the end of the fixed drill rod 1 to ensure that the drill slag can enter the soil bin between the drill rod outer wall 11 and the drill rod inner wall 12.

[0064] As the drill bit drills in, the debris enters the soil bin, ensuring the normal drilling operation of the drill bit, and the soil bin does not contact the drain pipe body, which will not damage the third filter layer 8 wrapped around the outside of the drain pipe body, nor will it block the pores on the third filter layer 8.

[0065] During the drilling process of the drill bit, when the pressure in the soil bin of the drill bit reaches the standard pressure, the drilling is suspended, and the drilling is continued after the drill residue in the soil bin of the drill bit is cleaned.

[0066] When the pressure in the soil bin reaches the standard pressure, it means that the soil bin is full or about to be full of debris and needs to be cleaned in time to ensure the normal progress of subsequent drilling.

[0067] The fixed drill rod 1 is provided with a movable cover plate 9, which can be connected to the soil bin in an opening and closing manner. A water pipe 10 is provided in the soil bin of the drill bit, and the water pipe 10 is connected to an external high-pressure water source. When the movable cover plate 9 is opened, high-pressure water is transported into the soil bin through the water pipe 10 by an external high-pressure water source to flush the drill cuttings out of the soil bin from the movable cover plate 9.

[0068] Preferably, the movable cover plate 9 can be hingedly arranged at the head end of the cylindrical structure of the fixed drill rod 1. Under the pressure of high-pressure water injection, the mixture of soil and water provides an outward extrusion thrust to the movable cover plate 9, so that the movable cover plate 9 is opened, thereby discharging the soil in the soil bin. When the water flowing out of the soil bin is relatively clear muddy water, it means that the drilling debris inside the soil bin has been cleaned up and the next drilling can be carried out.

[0069] Preferably, a pressure sensor can be arranged on the wall of the soil bin, and when the drill cuttings enter, pressure is generated on the wall of the soil bin, and the pressure in the soil bin is sensed by the pressure sensor. A standard pressure value is preset in the controller of the drilling rig, and when the pressure sensor senses that the pressure in the soil bin reaches the standard pressure, the pressure sensor sends an electrical signal to the controller of the drilling rig, so that the controller of the drilling rig controls the movable cover plate 9 to open, and realizes high-pressure water delivery through the water delivery pipe 10.

[0070] Step 4: When the drill bit reaches a certain depth, the drilling is stopped and the drill bit is extended by the detachable drill rod 3 .

[0071] The drill bit also includes a detachable drill rod 3, which has a cylindrical structure. The detachable drill rod 3 can be detachably coaxially connected to the tail end of the cylindrical structure of the fixed drill rod 1 through an active buckle 4, and two adjacent sections of the detachable drill rod 3 can be detachably coaxially connected through the active buckle 4.

[0072] The length of the drill bit can be extended by connecting the detachable drill rod 3 to meet the drilling depth requirement. Each time a section of the detachable drill rod 3 is added, the length of the detachable drill rod 3 can be adjusted according to the actual construction conditions. The movable buckle 4 can be a special buckle for the drill rod to ensure the reliable connection and synchronous rotation between the detachable drill rod 3 and the fixed drill rod 1, and between the detachable drill rod 3 and the detachable drill rod 3. The structure of the detachable drill rod 3 is the same as the cylindrical structure of the fixed drill rod 1, and the function of the fixed drill rod 1 is ensured while the fixed drill rod 1 is extended.

[0073] Before installing the detachable drill rod 3, first release the connection between the tail end of the fixed drill rod 1 and the output end of the drilling rig, then install the detachable drill rod 3 on the tail end of the fixed drill rod 1, and finally fix the tail end of the detachable drill rod 3 to the output end of the drilling rig. A slag inlet hole 15 connected to the soil bin is also reserved at the end of the detachable drill rod 3 to ensure that the drill slag can enter the soil bin between the outer wall 11 and the inner wall 12 of the drill rod.

[0074] Stop drilling when the drill bit reaches a point about 10 cm above the support surface.

[0075] A length of about 10 cm is reserved to facilitate the connection between the detachable drill rod 3 and the tail end of the fixed drill rod 1, or to facilitate the connection between the rear end of the detachable drill rod 3 and the tail end of the front detachable drill rod 3, leaving enough operating space for extending the installation of the detachable drill rod 3.

[0076] Step 5: coaxially insert the next drain pipe body into the detachable drill pipe 3, and coaxially plug the next drain pipe body with the previous drain pipe body, and the drilling rig continues to control the drill bit to drill.

[0077] The outer diameter of the drain pipe body is slightly smaller than the inner diameter of the detachable drill rod 3 of the drill bit, so that the drain pipe body can be coaxially inserted into the detachable drill rod 3, and the length of the drain pipe body is consistent with the length of the detachable drill rod 3.

[0078] After the drain pipe body is inserted into the detachable drill rod 3, the coaxiality of the two can be ensured to avoid misalignment during insertion, thereby protecting the coaxial sleeve connection of two adjacent drain pipe bodies. Since the tail end of the extended and installed detachable drill rod 3 needs to be connected to the output end of the drilling rig, the drain pipe body is not exposed after being inserted into the detachable drill rod 3, thereby avoiding interference with the connection between the detachable drill rod 3 and the drilling rig.

[0079] The end of the drain pipe 5 of the drain pipe body is formed with a connecting portion (not shown in the figure), so that two adjacent sections of the drain pipe 5 can be detachably coaxially connected through the connecting portion.

[0080] Preferably, the connecting portion can adopt an end expansion hole so that the drainage pipe 5 of the latter section can be sleeved on the drainage pipe 5 of the former section through the end expansion hole, and the plug-in method is adopted to facilitate the sequential plug-in of the drainage pipes 5 to form an integral drainage pipe structure.

[0081] The detachable drill rod 3 is a double-layer structure consisting of a drill rod outer wall 11 and a drill rod inner wall 12. The cavity between the drill rod outer wall 11 and the drill rod inner wall 12 forms a soil bin, and the soil bin in the detachable drill rod 3 is connected with the soil bin in the fixed drill rod 1; the drain pipe body is coaxially inserted into the drill rod inner wall 12 of the detachable drill rod 3; a water pipe 10 is provided in the soil bin of the detachable drill rod 3, and the water pipes in two adjacent sections of the detachable drill rod 3 can be connected in sequence and connected with the water pipe 10 in the fixed drill rod 1.

[0082] During the process of the drill bit continuing to drill, when the standard pressure is reached in the soil bin of the drill bit, the drilling is suspended, and the drilling debris in the soil bin of the drill bit is cleaned and the drilling is continued. The method of cleaning the debris here is the same as the method of cleaning the debris in the above step 3, and it will not be repeated here. During the extension of the drill bit, the soil bin capacity also increases accordingly, and the amount of debris that can be accommodated also increases accordingly. The standard pressure value should also increase and change synchronously with the extension of the drill bit, and the standard pressure values ​​of different sections can be set in the controller of the drilling rig.

[0083] Step 6: Repeat steps 4 and 5 until the drilling depth is slightly greater than the designed depth.

[0084] Step 7: Inject fine sand into the borehole and retract the drill rod so that the main body of the drain pipe is buried and installed inside the borehole.

[0085] The step 7 comprises the following sub-steps:

[0086] Step 7.1: Pull back the drill bit for a distance, open the triangular arc panel of the conical structure of the fixed drill rod 1 and make it parallel to the cylindrical structure through the controller of the drilling rig, and insert the jacking assembly coaxially into the borehole, and fix one end of the drain pipe body in the borehole through the jacking assembly.

[0087] Preferably, the length of the distance that the drill bit is pulled back is the radius of the cylindrical structure of the fixed drill rod 1.

[0088] Since the deepest part of the drill hole is conical, the drill bit needs to be pulled back a certain distance before the triangular arc panel can be opened. The pull-back distance can be determined according to the size of the conical structure of the fixed drill rod 1. The distance that the drilling depth is deeper than the designed depth is determined according to the pull-back distance. The fixed drill bit 2 is fixedly connected to a triangular arc panel of the fixed drill rod 1, and opens synchronously with the triangular arc panel, and the top rod 14 remains inside the fixed drill rod 1.

[0089] Step 7.2: Connect the water pipe 10 to the sand supply mechanism and inject fine sand into the borehole.

[0090] The jacking assembly can be buried at the bottom of the borehole by injecting fine sand, thereby positioning and fixing one end of the drain pipe body, preventing the drain pipe body from synchronously withdrawing from the borehole as the drill bit is pulled back, and ensuring that the drain pipe body is set inside the borehole.

[0091] Step 7.3: Continue to pull back the drill bit and inject fine sand until the drill bit is completely out of the borehole, bury the drain pipe body inside the borehole, and fill the gap between the drain pipe body and the hole wall with fine sand.

[0092] The fine sand forms a barrier between the main body of the drain pipe and the wall of the borehole, which prevents the third filter layer 8 from directly contacting the wall of the borehole and causing the pores to be blocked by soil, and also ensures the reliable installation of the main body of the drain pipe inside the borehole. The particle size of the fine sand can be selected according to the actual construction requirements to ensure the drainage function of the main body of the drain pipe. At the same time, the fine sand can also provide support for the borehole after the drill bit is pulled out, ensuring the formation of the borehole and avoiding the occurrence of hole collapse.

[0093] Step 7.4: Seal the outer surface of the gap between the drain pipe body and the drilled hole.

[0094] Preferably, concrete may be used to seal the outer surface of the gap between the drain pipe body and the drill hole to prevent fine sand from being retained in the drill hole.

[0095] During the slope support construction, the above steps can be repeated to complete the installation of all drainage pipe bodies.

[0096] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A construction method for a slope support drain pipe, characterized by: The following steps are involved: Step 1: Move the drilling rig into position according to the location of the drainage pipe laid out in the construction drawing; Step 2: Insert a section of the drain pipe into the drill bit and fix it with the jacking assembly; Step 3: Start the drilling machine, make the drill bit drill, and the drill cuttings are stored in the soil bin of the drill bit; Step 4: When the drill bit reaches a certain depth, the drilling is stopped and the drill bit is extended by the detachable drill rod (3); Step 5: coaxially insert the next drain pipe body into the detachable drill pipe (3), and coaxially plug the next drain pipe body with the previous drain pipe body, and the drilling rig continues to control the drill bit to drill; Step 6: Repeat steps 4 and 5 until the drilling depth is greater than the designed depth; Step 7: Inject fine sand into the borehole and retract the drill rod to bury the main body of the drain pipe inside the borehole; The drill bit comprises a fixed drill rod (1) and a fixed drill bit (2); the head of the fixed drill rod (1) is a conical structure, and the small head end of the conical structure is coaxially connected to the fixed drill bit (2); the tail of the fixed drill rod (1) is a cylindrical structure, the large head end of the conical structure is connected to the head end of the cylindrical structure, and the tail end of the cylindrical structure is connected to the output end of the drilling machine; The conical structure of the fixed drill rod (1) is composed of a plurality of triangular arc panels spliced ​​together, and the plurality of triangular arc panels can be installed in an openable manner at the head end of the cylindrical structure of the fixed drill rod (1); The push assembly is arranged in the conical structure of the fixed drill rod (1), and comprises a top plate (13) and a push rod (14); one surface of the top plate (13) is fitted and connected to one end of the drain pipe body close to the fixed drill bit (2), one end of the push rod (14) is coaxially and vertically connected to the top plate (13), and the other end of the push rod (14) is coaxially pressed against the small end of the conical structure and is rotatably connected to the fixed drill bit (2) via a ball shaft.

2. The construction method of the slope support drain pipe according to claim 1 is characterized by: The drill bit further comprises a detachable drill rod (3), which is in a cylindrical structure. The detachable drill rod (3) can be detachably coaxially connected to the rear end of the cylindrical structure of the fixed drill rod (1) via a movable buckle (4), and two adjacent sections of the detachable drill rod (3) can be detachably coaxially connected via the movable buckle (4).

3. The construction method of the slope support drain pipe according to claim 2 is characterized by: The fixed drill rod (1) is a double-layer structure consisting of a drill rod outer wall (11) and a drill rod inner wall (12); the cavity between the drill rod outer wall (11) and the drill rod inner wall (12) forms a soil bin; the drain pipe body is coaxially inserted into the drill rod inner wall (12) of the cylindrical structure of the fixed drill rod (1) through a jacking assembly; The detachable drill rod (3) is a double-layer structure consisting of a drill rod outer wall (11) and a drill rod inner wall (12); the cavity between the drill rod outer wall (11) and the drill rod inner wall (12) forms a soil bin; the soil bin in the detachable drill rod (3) is connected to the soil bin in the fixed drill rod (1); the drain pipe body is coaxially inserted into the drill rod inner wall (12) of the detachable drill rod (3); a water pipe (10) is provided in the soil bin of the detachable drill rod (3); the water pipes in two adjacent sections of the detachable drill rod (3) can be connected in sequence and connected to the water pipe (10) in the fixed drill rod (1).

4. The construction method of the slope support drain pipe according to claim 3 is characterized by: The drain pipe body comprises a drain pipe (5), a first filter layer (6), a second filter layer (7) and a third filter layer (8); a plurality of drain holes are formed at intervals on the drain pipe (5); the first filter layer (6) is wrapped around the drain pipe (5); the second filter layer (7) is wrapped around the first filter layer (6); and the third filter layer (8) is wrapped around the second filter layer.

5. The construction method of the slope support drain pipe according to claim 4 is characterized by: The drainage pipe (5) is a PVC pipe, the first filter layer (6) and the third filter layer (8) are non-woven fabrics, and the second filter layer (7) is graded gravel; The outer diameter of the drain pipe body is smaller than the inner diameter of the cylindrical structure of the fixed drill rod (1) of the drill bit, so that the drain pipe body can be coaxially inserted into the fixed drill rod (1); the length of each section of the drain pipe body is consistent with the length of the cylindrical structure of the fixed drill rod (1); The outer diameter of the drain pipe body is smaller than the inner diameter of the detachable drill rod (3) of the drill bit, so that the drain pipe body can be coaxially inserted into the detachable drill rod (3), and the length of the drain pipe body is consistent with the length of the detachable drill rod (3); A connecting portion is formed at the end of the drain pipe (5), so that two adjacent sections of the drain pipe (5) can be detachably coaxially connected via the connecting portion.

6. The construction method of the slope support drain pipe according to claim 3 is characterized by: The fixed drill rod (1) is provided with a movable cover plate (9), which can be connected to the soil bin in an openable and closable manner. A water pipe (10) is provided in the soil bin of the drill bit, and the water pipe (10) is externally connected to a high-pressure water source. When the movable cover plate (9) is opened, high-pressure water is transported into the soil bin through the water pipe (10) by the external high-pressure water source, so that the drill cuttings are flushed out of the soil bin from the movable cover plate (9).

7. The construction method of the slope support drain pipe according to claim 1 is characterized in that: During the drilling process of the drill bit, when the pressure in the soil bin of the drill bit reaches the standard pressure, the drilling is suspended, and the drilling is continued after the drill residue in the soil bin of the drill bit is cleaned; During the process of the drill bit continuing to drill, when the standard pressure is reached in the soil bin of the drill bit, the drilling is suspended, and the drilling is continued after the drill residue in the soil bin of the drill bit is cleaned.

8. The construction method of the slope support drain pipe according to claim 1 is characterized by: The step 7 comprises the following sub-steps: Step 7.1: The fixed drill rod (1) includes a conical structure and a cylindrical structure, and the conical structure includes a plurality of triangular arc panels; the drill bit is pulled back for a certain distance, and the triangular arc panels of the conical structure of the fixed drill rod (1) are opened and parallel to the cylindrical structure through the controller of the drilling rig, and the jacking assembly is coaxially inserted into the borehole, and one end of the drain pipe body is fixed in the borehole through the jacking assembly; Step 7.2: A water pipe (10) is provided in the soil bin, the water pipe (10) is connected to an external sand supply mechanism, and fine sand is injected into the borehole; Step 7.3: Continue to pull back the drill bit and inject fine sand until the drill bit is completely out of the borehole, bury the drain pipe body inside the borehole, and fill the gap between the drain pipe body and the hole wall with fine sand; Step 7.4: Seal the outer surface of the gap between the drain pipe body and the drilled hole.

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