Cast-in-place pile drilling device for tunnel construction and tunnel construction method

Abstract

The invention relates to the technical field of tunnel construction, in particular to a cast-in-place pile drilling device for tunnel construction and a tunnel construction method.The cast-in-place pile drilling device for tunnel construction comprises a supporting module, a drilling module and a vehicle body, the supporting module is used for supporting and limiting, the drilling module is used for drilling in cast-in-place pile construction and arranged on the supporting module, and the drilling module comprises a sleeve; a first connecting rod is arranged in the sleeve. According to the drilling device, the first connecting rod is arranged in the sleeve, the first connecting rod, the second connecting rod and the third connecting rod can move downwards in sequence, drilling is conducted in sequence through the first drill bit, the second drill bit and the third drill bit, in this way, step-by-step drilling can be conducted according to needs, the drill bits do not need to be replaced during drilling, and rapid drilling of the cast-in-place pile is facilitated; and meanwhile, the first connecting rod, the second connecting rod and the third connecting rod can be retracted into the sleeve, so that the overall length of the drilling module can be reduced, transfer and transportation of the drilling device are facilitated, and meanwhile the height requirement for construction can be lowered.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, in particular to a bored pile drilling device for tunnel construction and a tunnel construction method. Background Art

[0002] In tunnel construction, bored piles are a commonly used technology, especially in soft soil layers, loose soil layers or places where foundation reinforcement is required. Bored piles are formed by drilling holes around the tunnel construction area and pouring concrete to form a solid pile body to enhance the bearing capacity and stability of the foundation. During the construction of bored piles, it is necessary to first use a drilling device to drill holes, then hoist a steel cage into the hole, and finally pour concrete into the hole. Since the depth of bored piles is relatively deep, the drill rod of the drilling device is relatively long, which is relatively inconvenient during transportation and movement. At the same time, when drilling is relatively difficult and the hole needs to be gradually expanded, drill bits of different diameters need to be replaced, and drilling is more troublesome, which is not conducive to the rapid progress of tunnel construction.

[0003] At the same time, during the tunnel construction process, the planned underground tunnel and the existing operational elevated bridge may be intertwined, and the problem of the underground tunnel and the bridge foundation being close to each other will inevitably exist. The deformation of the bridge foundation will be greatly affected during the tunnel construction process. The existing method is to carry out multiple reinforcement measures such as grouting and isolation piles on the existing structure, but the above construction method is relatively costly and slow in construction speed. If the construction space is limited, the construction method cannot be further used. The use of traditional rotary jet pile construction cannot effectively control ground deformation and cannot well control the impact of stress on the adjacent bridge foundation. Therefore, the construction spacing requirements for bridge piers are relatively high. Summary of the invention

[0004] The object of the present invention is to provide a bored pile drilling device for tunnel construction and a tunnel construction method to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A bored pile drilling device for tunnel construction, comprising a support module, a drilling module, and a vehicle body;

[0007] The support module is used for support and limitation;

[0008] The drilling module is used for drilling holes in cast-in-place pile construction. The drilling module is arranged on the supporting module. The drilling module includes a sleeve. A connecting rod 1 is arranged inside the sleeve. A connecting rod 2 is slidably connected to the side of the connecting rod 1. A connecting rod 3 is slidably connected to the inner side of the sleeve on the side of the connecting rod 2. A drill bit 1 is fixedly connected to the bottom end of the connecting rod 1. A drill bit 2 is fixedly connected to the bottom end of the connecting rod 2 and is slidably connected to the side of the drill bit 1. A drill bit 3 is fixedly connected to the bottom of the side of the connecting rod 3 and is slidably connected to the side of the drill bit 2.

[0009] The vehicle body is arranged at the bottom of the supporting module, and the vehicle body is used for walking.

[0010] Furthermore, two connecting grooves are provided on the sides of the connecting rod one, the connecting rod two and the connecting rod three, and a connecting block is slidably connected to the bottom of the inner side of the connecting groove, and the inner side surfaces of the sleeve, the connecting rod two and the connecting rod three are fixedly connected to the sides of two adjacent connecting blocks.

[0011] Furthermore, the support module comprises:

[0012] A limiting rod is arranged on one side of the sleeve, and a fixing seat is fixedly connected to the side of the limiting rod;

[0013] A sliding seat is slidably connected to the top of the side of the limiting rod, and the inner side of the sliding seat is rotatably connected to the top of the side of the sleeve;

[0014] A driving seat is fixedly connected to the bottom end of the limiting rod, the sleeve passes through the driving seat, and the side of the driving seat away from the drilling module is fixedly connected to the limiting seat;

[0015] Two hydraulic rods 1 are arranged on one side close to the vehicle body, and the top ends of the two hydraulic rods 1 are rotatably connected to the inner side surface of the fixing seat through shaft rods;

[0016] A connecting seat is arranged at the bottom end of the hydraulic rod one, the bottom ends of the two hydraulic rods one are rotatably connected to the inner side surface of the connecting seat through an axle rod, the side surface of the limit seat is rotatably connected to the inner side surface of the connecting seat through the axle rod, and two positioning rods are arranged on the inner side surface of the connecting seat, and one end of the two positioning rods is fixedly connected to the vehicle body;

[0017] The fixed rod is fixedly connected to the bottom surface of the driving seat. The inner side of the fixed rod is provided with a second hydraulic rod. The output end of the second hydraulic rod is transmission-connected with an abutment rod which is slidably connected to the inner side of the fixed rod.

[0018] Furthermore, a sliding groove is provided on the side of the limit rod corresponding to the sliding seat, an adjusting screw rod which is screwed and connected to the inner side of the sliding seat is rotatably connected to the inner side of the sliding seat, a power motor is fixedly connected to the top of the limit rod, and an output end of the power motor is transmission-connected to the top of the adjusting screw rod;

[0019] A driving motor is provided on the inner side of the driving seat, and the output end of the driving motor is transmission-connected with a driving shaft rotatably connected to the inner side of the driving seat, and the inner side of the driving seat is rotationally connected with a driving ring slidably connected to the side of the sleeve, and two locking grooves are provided on the side of the sleeve, and two locking blocks are fixedly connected to the inner side of the adjacent locking grooves on the inner side of the driving ring, and the side of the driving ring and the side of the driving shaft are fixedly sleeved with driving gears, and the two driving gears are meshed for transmission.

[0020] Preferably, the top of the sleeve is fixedly connected to an adjusting box rotatably connected to the inner side surface of the sliding seat, the top surface of the adjusting box is rotatably connected to a positioning box fixedly connected to the inner side surface of the sliding seat, the inner side surface of the positioning box is provided with a threaded rod rotatably connected to the side surface of the adjusting box, the top surfaces of the connecting rod 1, the connecting rod 2 and the connecting rod 3 are all provided with threaded holes, and the side surfaces of the threaded rods are screwed and connected with the threaded holes on the connecting rod 1;

[0021] The inner side surface of the adjustment box is rotatably connected to two winding rods, and the ends of the two winding rods close to each other are rotatably connected to a positioning ring rotatably connected to the side surface of the threaded rod, and the sides of the two winding rods are both wound with limiting ropes extending to the inside of the sleeve, one limiting rope passes through the inside of the connecting rod three and is fixedly connected to the top surface of the connecting rod two, and the bottom end of the other limiting rope is fixedly connected to the top surface of the connecting rod three.

[0022] Furthermore, the inner side of the adjustment box is rotatably connected to two adjustment rods corresponding to the retracting rods, the top of the inner side of the adjustment box is fixedly connected to a fixing ring rotatably connected to the two adjustment rods, the side of the adjustment rod is fixedly sleeved with a worm, and the side of the retracting rod is fixedly sleeved with a worm wheel meshing with an adjacent worm;

[0023] The inner side surface of the positioning box is fixedly connected to two adjusting motors corresponding to the adjusting rods, the output end of the adjusting motor is transmission-connected with a transmission rod rotatably connected to the inner side surface of the positioning box, the bottom of the side surface of the transmission rod is fixedly sleeved with a transmission gear, the top of the side surface of the adjusting rod is fixedly sleeved with a connecting gear, the bottom surface of the positioning box is fixedly connected to a limiting ring rotatably connected to the top surface of the adjusting box, the inner side surface of the bottom of the positioning box and the side surface of the limiting ring are both rotationally connected to two connecting gear rings, and the transmission gear and the connecting gear located on the same side of the limiting ring are meshed with a corresponding connecting gear ring for transmission.

[0024] Preferably, the inner side surface of the positioning box is fixedly connected to a bellows passing through the inside of the threaded rod, the bottom end of the bellows is fixedly connected to a connecting tube, the inner bottom surface of drill bit one is fixedly connected to a fixed tube rotatably connected to the bottom end of the connecting tube, a plurality of open grooves one are provided at the bottom of the side surface of connecting rod one, and the top surfaces of drill bit two and drill bit three are both provided with open grooves two.

[0025] The tunnel construction method includes the following construction steps: surveying and setting out - construction of retaining structures - construction of column piles - pit bottom reinforcement - foundation pit dewatering - foundation pit excavation. The specific steps are as follows:

[0026] Step (1) Surveying and staking out: Calculate the coordinates of the project's proposed structure points based on the control pile positions, construction drawings and related design documents, use a total station to conduct on-site construction staking out, make relevant marks, and use re-measurement to ensure measurement accuracy;

[0027] Step (2) Construction of retaining structure: First, bored cast-in-place piles are constructed. A drilling device is used to drill bored piles. Then, a steel cage is hoisted into the hole. Finally, concrete is poured. If the clearance height under the bridge cannot meet the construction conditions, the drilling rig construction operation is carried out by modifying the original circulating drilling rig and lowering the site elevation. The water-stop curtain within 12m of the low clearance section adjacent to the bridge pile foundation section is constructed using MJS, while the water-stop curtain of the remaining sections of the bored piles is constructed using double-row triple-tube high-pressure rotary jet piles. Three rotary jet piles are used to stop water at the cold joints with other surrounding support forms. Finally, the crown beam and the first-floor concrete support are constructed;

[0028] Step (3) Column pile construction: first carry out the preliminary hole-forming construction, the lattice column is processed and manufactured on site, then the steel cage and the lattice column are installed, and then concrete is poured and backfilled with sand and gravel;

[0029] Step (4) pit bottom reinforcement: double-tube high-pressure jet grouting piles are used to reinforce the tunnel excavation construction area near the bridge pile foundation, and the construction process is the same as the high-pressure jet grouting pile water-stop curtain;

[0030] Step (5) foundation pit dewatering: pipe well dewatering is adopted in the foundation pit, drainage wells are set up, and a dewatering well is set up every 20m. The well wall pipe adopts cement gravel filter pipe, and the bottom is overlapped with a sand settling pipe. The filter pipe is wrapped with a layer of nylon mesh. A longitudinal intercepting ditch is set around the foundation pit. At the same time, a proper amount of water level monitoring holes are set up inside and outside the foundation pit to monitor the groundwater level in the foundation pit;

[0031] Step (6) foundation pit excavation: The foundation pit is excavated adjacent to the bridge foundation section, divided into north and south sides. The earthwork excavation of the foundation pits on the north and south sides is excavated from both sides to the middle, and the excavation is retreated in a stepped manner along the bottom of the foundation pits on both sides toward the middle.

[0032] Furthermore, during the MJS construction process in step (2), the control points of the MJS pile construction are first determined, and then trenches are excavated. The trenches are excavated about 500 mm on both sides of the center of the jet grouting pile, and the depth is generally about 1 m. Then, the drilling rig is in place, and leveling, centering and verticality adjustments are performed. Before drilling, the mud pump is debugged to ensure that the equipment operates normally. The pilot hole drilling depth is slightly deeper than the design depth by 0.5 to 1.0 m. Finally, the jet grouting is lifted. After the drill rod is lowered to the design elevation, grouting is started. After the ground pressure reaches the design value, backwater suction is started and the jet grouting step lifting is started. During the grouting process, close attention is paid to the ground pressure and mud discharge, and the size of the mud discharge valve is controlled in time to ensure that the ground pressure value is controlled within the design requirement range to reduce the disturbance to the adjacent structures.

[0033] Preferably, during the excavation of the foundation pit in step (6), when the excavation reaches the second support, the construction of the steel purlin and the erection of the steel support are started, and an axial force servo system is used at one end of the steel support to monitor the stress state of the steel support support system in real time through a pressure sensor, a control system and a hydraulic pump, and to perform intelligent control of automatic low-pressure compensation and automatic high-pressure alarm, and to adjust the axial force in real time.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. A connecting rod 1 is arranged inside the sleeve. During the bored pile drilling process, the connecting rod 1, the connecting rod 2 and the connecting rod 3 can be synchronously moved downward and extended out of the sleeve, and the drilling can be performed simultaneously through the drill bit 1, the drill bit 2 and the drill bit 3. During the drilling process, the connecting rod 1 can first drive the drill bit 1 to move downward to drill according to the needs, and then the connecting rod 2 can drive the drill bit 2 to move downward to drill, and finally the drill bit 3 can be used to drill. In this way, drilling can be performed step by step according to the needs, and the drill bit does not need to be replaced during drilling, which is conducive to the rapid boring of the bored pile. At the same time, the connecting rod 1, the connecting rod 2 and the connecting rod 3 can all be retracted into the sleeve, which can reduce the overall length of the drilling module, is conducive to the transfer and transportation of the drilling device, and can also reduce the height requirement of the construction.

[0036] 2. By using partial MJS for isolation and protection construction in the bidirectional section adjacent to the bridge foundation, compared with traditional rotary jet piles, it is possible to monitor ground stress, reasonably control construction parameters, effectively control surface deformation, greatly reduce the deformation impact on the adjacent bridge foundation, and optimize the support form.

[0037] 3. By modifying the circulating drilling rig and optimizing the technical measures of the construction site elevation, the low-headroom full-casing rotary drilling rig construction bored pile operation was replaced. Under the dual control of safety and quality, the construction period was saved and good economic benefits were achieved. The deep foundation pit base was fully reinforced with high-pressure rotary jet piles to enhance lateral resistance, reduce pit bottom bulge and deformation of the surrounding structure, and further reduce deformation of adjacent structures.

[0038] 4. Through the use of steel support servo axial force system during foundation pit excavation, real-time monitoring and control of support axial force is achieved, which solves the problem that the traditional movable head manually applies axial force and cannot strictly control the deformation of the foundation pit side wall and the risk of uncontrollable safety of the surrounding environment, and has good social benefits.

[0039] 5. By adding lattice column nodes symmetrically adjacent to the foundation pit of the bridge foundation section, the overall stability of the support can be enhanced, the deformation of the retaining structure can be better controlled, and the disturbance to the surrounding environment can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of a bored pile drilling device for tunnel construction and a tunnel construction method of the present invention;

[0041] Figure 2 It is a schematic diagram of the support module structure in the present invention;

[0042] Figure 3 It is a schematic diagram of the internal structure of the limit rod in the present invention;

[0043] Figure 4 It is a schematic diagram of the internal structure of the fixing rod in the present invention;

[0044] Figure 5 It is a schematic diagram of the drilling module structure in the present invention;

[0045] Figure 6 It is a schematic diagram of the internal structure of the sleeve in the present invention;

[0046] Figure 7 It is a schematic diagram of the internal structure of the regulating box in the present invention;

[0047] Figure 8 This is a schematic diagram of the structure of the connecting gear ring in the present invention when viewed from above;

[0048] Fig. 9 It is a schematic diagram of the internal structure of the connecting rod in the present invention;

[0049] Fig.10 It is a structural schematic diagram of a connecting rod in the present invention;

[0050] Fig.11 It is a schematic diagram of the flow of the tunnel construction method of the present invention.

[0051] In the figure: 100, support module; 110, limit rod; 111, fixed seat; 112, sliding slot; 113, adjusting screw; 114, power motor; 120, sliding seat; 130, driving seat; 131, driving ring; 132, blocking block; 133, driving motor; 134, driving shaft; 135, driving gear; 136, limit seat; 140, hydraulic rod 1; 150, connecting seat; 151, positioning rod; 160, fixing rod; 161, hydraulic rod 2; 162, abutting rod; 200, drilling module; 210, sleeve; 211, blocking slot; 220, connecting rod 1; 221, drill bit 1; 222, fixed pipe; 230, connecting rod 2; 231, drill bit 2; 240, connecting rod 3; 241, drill bit 3; 250, connecting groove; 251, connecting block; 260, adjusting box; 261, limiting rope; 262, winding rod; 263, positioning ring; 264, adjusting rod; 265, worm; 266, worm wheel; 267, connecting gear; 268, fixed ring; 270, positioning box; 271, limiting ring; 272, connecting gear ring; 273, adjusting motor; 274, transmission rod; 275, transmission gear; 280, threaded rod; 290, bellows; 291, connecting pipe; 300, vehicle body. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] See also Figure 1-9 In an embodiment of the present invention, a bored pile drilling device for tunnel construction includes a support module 100, a drilling module 200, and a vehicle body 300;

[0054] The support module 100 is used for supporting and limiting;

[0055] The drilling module 200 is used for drilling holes in cast-in-place pile construction. The drilling module 200 is arranged on the supporting module 100. The drilling module 200 includes a sleeve 210. A connecting rod 1 220 is arranged inside the sleeve 210. A connecting rod 230 is slidably connected to the side of the connecting rod 1 220. A connecting rod 3 240 slidably connected to the inner side of the sleeve 210 is slidably connected to the side of the connecting rod 230. The sleeve 210 can shield the connecting rod 1 220, the connecting rod 230, and the connecting rod 3 240. A drill bit 221 is fixedly connected to the bottom end of the connecting rod 1 220, a drill bit 231 slidably connected to the side of the drill bit 1 221 is fixedly connected to the bottom end of the connecting rod 2 230, a drill bit 3 241 slidably connected to the side of the drill bit 231 is fixedly connected to the bottom of the side of the connecting rod 3 240, and a plurality of protrusions are arranged at the bottom of the drill bit 1 221, the drill bit 231 and the drill bit 3 241 to facilitate the smooth drilling. The vehicle body 300 is arranged at the bottom of the supporting module 100, and the vehicle body 300 is used for walking.

[0056] Specifically, during the process of bored pile drilling, the connecting rod 1 220, the connecting rod 230, and the connecting rod 3 240 can be synchronously moved downward and extended out of the sleeve 210, and the drilling is performed simultaneously by the drill bit 1 221, the drill bit 231, and the drill bit 3 241. At the same time, the sleeve 210 can be moved downward to drill to a deeper depth, and the connecting rod 1 220, the connecting rod 230, and the connecting rod 3 240 can all be retracted into the sleeve 210. In this way, the overall length of the drilling module 200 can be reduced, which is beneficial to the transfer and transportation of the drilling device. At the same time, the height requirement for construction can be lowered, which is convenient for construction in areas such as the bottom of a bridge. During the drilling process, the connecting rod 1 220 can first drive the drill bit 1 221 to move downward to drill a hole, and then the connecting rod 230 can drive the drill bit 231 to move downward to drill a hole, and finally the drill bit 3 241 can be used to drill a hole, so that the drill bit 1 221, the drill bit 231 and the drill bit 3 241 drill downwards in sequence, thereby drilling holes step by step as needed. There is no need to replace the drill bit during drilling, which is conducive to the rapid drilling of cast-in-place piles.

[0057] Embodiment 1

[0058] like Figure 2-4 As shown, in this embodiment, the support module 100 includes a limit rod 110, a sliding seat 120, a driving seat 130, two hydraulic rods 140, a connecting seat 150, and a fixing rod 160;

[0059] The limiting rod 110 is arranged on one side of the sleeve 210, and a fixing seat 111 is fixedly connected to the side of the limiting rod 110, and the sliding seat 120 is slidably connected to the top of the side of the limiting rod 110, and the inner side of the sliding seat 120 is rotatably connected to the top of the side of the sleeve 210, and the driving seat 130 is fixedly connected to the bottom end of the limiting rod 110, and the sleeve 210 passes through the inside of the driving seat 130, and the side of the driving seat 130 away from the drilling module 200 is fixedly connected to the limiting seat 136, and two hydraulic rods 140 are arranged on the side close to the vehicle body 300, and the tops of the two hydraulic rods 140 are rotatably connected to the inner side of the fixing seat 111 through the shaft rod;

[0060] The connecting seat 150 is arranged at the bottom end of the hydraulic rod 140, and the bottom ends of the two hydraulic rods 140 are rotatably connected to the inner side surface of the connecting seat 150 through an axle rod. The side surface of the limit seat 136 is rotatably connected to the inner side surface of the connecting seat 150 through an axle rod. Two positioning rods 151 are arranged on the inner side surface of the connecting seat 150, and one end of the two positioning rods 151 is fixedly connected to the vehicle body 300. The vehicle body 300 supports the connecting seat 150 through the positioning rods 151. The connecting seat 150 can support the driving seat 130 and the limiting rod 110 through the hydraulic rod 140 and the limiting seat 136. The fixing rod 160 is fixedly connected to the bottom surface of the driving seat 130, and the inner side surface of the fixing rod 160 is provided with a hydraulic rod 2 161. The output end of the hydraulic rod 2 161 is transmission-connected with an abutting rod 162 that is slidably connected to the inner side surface of the fixing rod 160.

[0061] During specific implementation, the angle of the limit rod 110 can be adjusted by extending and retracting the hydraulic rod 140. During transportation, the limit rod 110 and the drilling module 200 can be rotated downward to reduce the height of the drilling module 200, and the drilling module 200 can be erected by extending the hydraulic rod 140. Drilling is performed through the drilling module 200, and the sliding seat 120 can support the top of the sleeve 210. The sliding seat 120 can move up and down along the limit rod 110, so that the sleeve 210 moves downward to perform the drilling operation. The abutment rod 162 can be extended by the hydraulic rod 2 161, so that the abutment rod 162 moves downward to abut against the ground, which is beneficial to improve the stability of the limit rod 110 and thus improve the stability of drilling.

[0062] like Figure 3 , 9As shown in Figures 10, in this embodiment, two connecting grooves 250 are provided on the sides of the connecting rod 1 220, the connecting rod 230 and the connecting rod 3 240, and a connecting block 251 is slidably connected to the bottom of the inner side of the connecting groove 250. The inner sides of the sleeve 210, the connecting rod 230 and the connecting rod 3 240 are fixedly connected to the sides of two adjacent connecting blocks 251. A sliding groove 112 is provided on the side of the limiting rod 110 corresponding to the sliding seat 120. The inner side of the sliding groove 112 is rotatably connected to an adjusting screw rod 113 that is screwed and connected to the inner side of the sliding seat 120. The adjusting screw rod 113 can limit the position of the sliding seat 120, and the sliding seat 120 can limit the height of the sleeve 210. The top of the limiting rod 110 is fixedly connected to a power motor 114, and the output end of the power motor 114 is drivingly connected to the top of the adjusting screw rod 113.

[0063] A driving motor 133 is provided on the inner side of the driving seat 130, and the output end of the driving motor 133 is transmission-connected with a driving shaft 134 rotatably connected to the inner side of the driving seat 130. The inner side of the driving seat 130 is rotationally connected with a driving ring 131 slidably connected to the side of the sleeve 210. Two locking grooves 211 are provided on the side of the sleeve 210. The inner side of the driving ring 131 is fixedly connected with two locking blocks 132 slidably connected to the inner sides of adjacent locking grooves 211. The locking blocks 132 can slide up and down inside the locking grooves 211, and the sleeve 210 can move up and down in the driving ring 131. The side of the driving ring 131 and the side of the driving shaft 134 are fixedly sleeved with driving gears 135, and the two driving gears 135 are meshed for transmission.

[0064] In a specific implementation, when drilling, the driving motor 133 can drive the driving shaft 134 to rotate, the driving shaft 134 can drive the driving ring 131 to rotate through the driving gear 135, the driving ring 131 can drive the sleeve 210 to rotate through the positioning block 132 and the positioning groove 211, the sleeve 210 can drive the connecting rod three 240 to rotate through the corresponding connecting groove 250 and the connecting block 251, the connecting rod three 240 can drive the connecting rod two 230 to rotate through the connecting groove 250 and the connecting block 251, and the connecting rod two 230 can drive the connecting rod three 240 through the connecting groove 250 and the connecting block 251. Rod 1 220 rotates, so that the sleeve 210, connecting rod 1 220, connecting rod 230, and connecting rod 3 240 rotate synchronously, and the sleeve 210, connecting rod 1 220, connecting rod 230, and connecting rod 3 240 can be prevented from separating from each other through the connecting block 251 and the connecting groove 250. The adjusting screw 113 can be driven to rotate by the power motor 114. The rotation of the adjusting screw 113 can make the sliding seat 120 move downward, and the sliding seat 120 can drive the sleeve 210 to move downward, so that the sleeve 210 moves downward and rotates, so as to drill downward through the drilling module 200.

[0065] Embodiment 2

[0066] Based on the first embodiment, Figure 6-9 As shown, in this embodiment, the top of the sleeve 210 is fixedly connected to an adjusting box 260 that is rotatably connected to the inner side surface of the sliding seat 120, the top surface of the adjusting box 260 is rotatably connected to a positioning box 270 that is fixedly connected to the inner side surface of the sliding seat 120, the inner side surface of the positioning box 270 is provided with a threaded rod 280 that is rotatably connected to the side surface of the adjusting box 260, the top surfaces of the connecting rod 1 220, the connecting rod 230 and the connecting rod 3 240 are all provided with threaded holes, the side surface of the threaded rod 280 is screwed and connected with the threaded hole on the connecting rod 1 220, the positioning box 270 can limit the height of the threaded rod 280, and the threaded rod 280 can limit the height of the connecting rod 1 220;

[0067] Two reeling rods 262 are rotatably connected to the inner side of the adjustment box 260, and one end of the two reeling rods 262 close to each other is rotatably connected to a positioning ring 263 rotatably connected to the side of the threaded rod 280, and the sides of the two reeling rods 262 are both wound with limiting ropes 261 extending to the inside of the sleeve 210, one limiting rope 261 passes through the inside of the connecting rod 3 240 and is fixedly connected to the top surface of the connecting rod 230, and the bottom end of the other limiting rope 261 is fixedly connected to the top surface of the connecting rod 3 240, and the reeling rod 262 can limit the height of the connecting rod 3 240 and the connecting rod 2 230 through the limiting rope 261;

[0068] The inner side surface of the positioning box 270 is fixedly connected to a bellows 290 passing through the inside of the threaded rod 280, the bottom end of the bellows 290 is fixedly connected to a connecting pipe 291, the inner bottom surface of the drill bit 221 is fixedly connected to a fixed pipe 222 rotatably connected to the bottom end of the connecting pipe 291, a plurality of open grooves 1 are provided at the bottom of the side surface of the connecting rod 1 220, and the top surfaces of the drill bits 231 and the drill bits 3 241 are both provided with open grooves 2.

[0069] In a specific implementation, when the sliding seat 120 moves downward, the threaded rod 280 can be moved downward by adjusting the box 260 and the positioning box 270, so that the connecting rod 220 moves downward, the connecting rod 220 and the drill bit 221 move downward and rotate, and the drill bit 221 drills a hole. The height of the sleeve 210 can be maintained by the sliding seat 120, and the sleeve 210 can be used to drive the fixed tube 222, the connecting rod 230, and the connecting rod 3 240 to rotate. The threaded holes are screwed on the threaded rod 280, and the two limit ropes 261 respectively maintain the height of the second connecting rod 230 and the third connecting rod 240, so that the threaded holes on the second connecting rod 230 and the third connecting rod 240 are disengaged from the threads on the threaded rod 280, so that when the first connecting rod 220 rotates relative to the threaded rod 280, the first connecting rod 220 can move downward along the threaded rod 280, and then the first connecting rod 220 and the drill bit 1 221 can move downward relative to the sleeve 210, so that the drill bit 1 221 can drill a hole;

[0070] After the threaded hole on the connecting rod 220 moves downward and disengages from the thread on the threaded rod 280, the connecting rod 220 will no longer move downward, and then a reeling rod 262 can be rotated to release a limiting rope 261. At this time, under the action of gravity, the connecting rod 230 will move downward, so that the threaded hole on the connecting rod 230 will contact the threaded rod 280, so that the threaded hole on the connecting rod 230 will be screwed with the threaded rod 280, thereby causing the connecting rod 230 to move downward along the threaded rod 280. The drill bit 231 is moved downward and rotated, and the hole is expanded by the drill bit 231. The connecting rod 230 is moved to the bottom of the threaded rod 280, and the threaded hole on the drill bit 231 is disengaged from the thread on the threaded rod 280. Another limit rope 261 can be released through another retracting rod 262, so that the connecting rod 3 240 is moved downward, and the threaded hole on the connecting rod 3 240 is screwed with the threaded rod 280, and then the drill bit 241 is moved downward to expand the hole, so as to perform step-by-step drilling as needed;

[0071] When drilling, two limit ropes 261 can be released at the same time, so that the connecting rod 230 and the connecting rod 3 240 move downward synchronously with the connecting rod 1 220, so that the drill bit 1 221, the drill bit 231 and the drill bit 3 241 can drill synchronously, and the top of the bellows 290 can be connected to the delivery pump. During the drilling process, water can be continuously added to the hole. The water can pass through the open groove 2 on the connecting rod 230 and the connecting rod 3 240, then pass through the open groove 1, and finally pass through the fixed pipe 222 to enter the connecting pipe 291, and then be discharged through the bellows 290, so that the drill bit 1 221 and the like are cooled by the flow of water, and the drilled soil, gravel, etc. are discharged at the same time. The bellows 290 and the connecting pipe 291 can rotate relative to the fixed pipe 222 to prevent the bellows 290 from twisting.

[0072] A large end is provided at the bottom of the threaded rod 280 to prevent the connecting rod 220 from being separated from the threaded rod 280 .

[0073] like Figure 7-8 As shown, in this embodiment, the inner side surface of the adjustment box 260 is rotatably connected to two adjustment rods 264 corresponding to the reeling rod 262, the top of the inner side surface of the adjustment box 260 is fixedly connected to a fixing ring 268 rotatably connected to the two adjustment rods 264, the side surface of the adjustment rod 264 is fixedly sleeved with a worm 265, and the side surface of the reeling rod 262 is fixedly sleeved with a worm wheel 266 meshing with the adjacent worm 265, and the adjustment rod 264 can limit the angle of the reeling rod 262 through the worm 265 and the worm wheel 266, thereby limiting the height of the connecting rod 230 and the connecting rod 3 240 respectively through two limiting ropes 261;

[0074] Two adjusting motors 273 are fixedly connected to the inner side surface of the positioning box 270 corresponding to the adjusting rod 264, and the output end of the adjusting motor 273 is drivingly connected to the transmission rod 274 rotatably connected to the inner side surface of the positioning box 270, and a transmission gear 275 is fixedly sleeved on the bottom of the side surface of the transmission rod 274, and a connecting gear 267 is fixedly sleeved on the top of the side surface of the adjusting rod 264. The bottom surface of the positioning box 270 is fixedly connected to a limiting ring 271 rotatably connected to the top surface of the adjusting box 260, and the inner side surface of the bottom of the positioning box 270 and the side surface of the limiting ring 271 are both rotatably connected to two connecting toothed rings 272, and the transmission gear 275 and the connecting gear 267 located on the same side of the limiting ring 271 are both meshed with a corresponding connecting toothed ring 272 for transmission, and one group of connecting gears 267 and the transmission gear 275 are both meshed with the connecting toothed ring 272 on the side wall of the limiting ring 271, and the other group of connecting gears 267 and the transmission gear 275 are both meshed with the connecting toothed ring 272 on the inner wall of the positioning box 270.

[0075] In a specific implementation, when the second connecting rod 230 and the third connecting rod 240 rotate, the sleeve 210 can drive the adjusting box 260 to rotate, so that the winding rod 262 and the adjusting rod 264 rotate with the sleeve 210 to avoid the twisting of the limit rope 261. At the same time, the two adjusting motors 273 can drive the adjacent transmission rods 274 to rotate. The transmission rod 274 can drive the corresponding connecting gear ring 272 to rotate through the transmission gear 275, so that the connecting gear ring 272 rotates with the connecting gear 267 to avoid the self-rotation of the connecting gear 267. In this way, when the drill bit 1 221 drills downward, the height of the drill bit 231 and the drill bit 3 241 can be maintained. After the drill bit 1 221 completes drilling, an adjusting motor 273 can be driven to rotate. The movable transmission rod 274 rotates in the opposite direction, so that the transmission rod 274 drives a connecting toothed ring 272 to rotate in the opposite direction through the transmission gear 275, so that a connecting toothed ring 272 can rotate relative to the adjustment box 260, and a connecting toothed ring 272 will drive the connecting gear 267 to rotate, so that an adjusting rod 264 rotates, and the adjusting rod 264 can drive a reeling rod 262 to rotate through the worm 265 and the worm wheel 266, thereby releasing a limiting rope 261, so that the connecting rod 230 moves downward, and then the corresponding reeling rod 262 can be driven to rotate through another adjusting motor 273, releasing another limiting rope 261, so that the connecting rod 3 240 moves downward, so as to perform step-by-step drilling as needed.

[0076] In the present invention, the top end of the threaded rod 280 can be extended to the top of the positioning box 270, and then a motor is set on the top of the positioning box 270, and linkage gears are set on the output shaft of the motor and the top of the side of the threaded rod 280, so that the two linkage gears are meshed. In this way, the output shaft of the motor can drive the threaded rod 280 to rotate through the linkage gear, and the relative rotation speed of the threaded rod 280 and the connecting rod 220 can be adjusted as needed, thereby adjusting the drilling speed.

[0077] See also Fig.11 In the embodiment of the present invention, the tunnel construction method includes the construction steps of surveying and setting out - construction of retaining structure - construction of column piles - pit bottom reinforcement - foundation pit dewatering - foundation pit excavation, and the specific steps are as follows:

[0078] Step (1) Surveying and staking out: Calculate the coordinates of the project's proposed structure points based on the control pile positions, construction drawings and related design documents, use a total station to conduct on-site construction staking out, make relevant marks, and use re-measurement to ensure measurement accuracy;

[0079] Step (2) Construction of retaining structure: First, bored cast-in-place piles are constructed. A drilling device is used to drill bored piles. Then, a steel cage is hoisted into the hole. Finally, concrete is poured. If the clearance height under the bridge cannot meet the construction conditions, the drilling rig is modified by refitting the original circulating drilling rig and lowering the site elevation. The water-stop curtain within 12m of the low clearance section adjacent to the bridge pile foundation section is constructed using MJS. The water-stop curtain for the remaining sections of the bored piles is constructed using double-row triple-tube high-pressure rotary jet piles. Three rotary jet piles are used to stop water at the cold joints with other surrounding support forms. Finally, the crown beam and the first-floor concrete support are constructed.

[0080] Step (3) Column pile construction: first carry out the preliminary hole-forming construction, the lattice column is processed and manufactured on site, then the steel cage and the lattice column are installed, and then concrete is poured and backfilled with sand and gravel;

[0081] Step (4) pit bottom reinforcement: double-tube high-pressure jet grouting piles are used to reinforce the tunnel excavation construction area near the bridge pile foundation, and the construction process is the same as the high-pressure jet grouting pile water-stop curtain;

[0082] Step (5) foundation pit dewatering: pipe well dewatering is adopted in the foundation pit, drainage wells are set up, and a dewatering well is set up every 20m. The well wall pipe adopts cement gravel filter pipe, and the bottom is overlapped with a sand settling pipe. The filter pipe is wrapped with a layer of nylon mesh. A longitudinal intercepting ditch is set around the foundation pit. At the same time, a proper amount of water level monitoring holes are set up inside and outside the foundation pit to monitor the groundwater level in the foundation pit;

[0083] Step (6) foundation pit excavation: The foundation pit is excavated adjacent to the bridge foundation section, divided into north and south sides. The earthwork excavation of the foundation pits on the north and south sides is excavated from both sides to the middle, and the excavation is retreated in a stepped manner along the bottom of the foundation pits on both sides toward the middle.

[0084] During the specific implementation, the construction of the retaining structure adopts a construction method that combines bored cast-in-place pile construction, MJS construction, high-pressure rotary jet pile construction, crown beam and first-floor concrete support construction.

[0085] During the bored pile construction, if the clearance height under the bridge cannot meet the construction conditions, drilling construction can be carried out by using a drilling device or modifying the original circulating drilling rig. At the same time, the site elevation can be lowered. The bored piles should be constructed in an interval sequence. The distance between the piles that have been poured with concrete and the adjacent piles should be greater than four times the pile diameter, so as to further avoid construction problems such as hole collapse encountered during the construction process.

[0086] First, use the total station to lay out the pile points, and control the deviation of the pile points within ±1cm; then, bury the casing, the top of the casing should be 0.3m above the ground surface, the casing should be consistent with the center of the pile position, and the deviation should not be greater than 50mm; then, the drilling rig is in place to start drilling, and the drilling speed, drill rod verticality and mud surface height are controlled. After drilling to the designed elevation, the hole is cleaned to ensure that the thickness of the sediment at the bottom of the hole meets the construction specifications; finally, the steel cage hole is made, hoisted and underwater concrete is poured using the catheter method.

[0087] During the construction of high-pressure rotary jet piles, the construction sequence of rotary jet piles adopts the method of alternate holes, and the time interval between grouting of adjacent holes should not be greater than 24h. First, determine the pile position, move the rotary jet pile machine to the designated pile position, and conduct equipment inspection. Then, perform drilling operations. After the drilling rig drills to the designed depth, connect the grouting pump, and then perform grouting from bottom to top. Adjust and control the construction parameters on site according to the construction conditions. The grouting pressure is 2MPa, the grouting volume is 100-150L / min, the air pressure is 0.5-0.7MPa, the air volume is 10m / min, the water pressure is 20-30MPa, the water flow is 80-120L / min, and the lifting speed is 0.1m / min.

[0088] During the construction of the crown beam and the first-floor concrete support, first, the position and elevation of the crown beam and the first concrete support are laid out and marked, then the poured pile head concrete is chiseled out to 5 cm above the crown beam bottom elevation, cleaned and applied with a plain concrete cushion layer, and finally the steel bar binding, formwork erection, concrete pouring and maintenance are carried out.

[0089] like Fig.11 As shown, in this embodiment, during the MJS construction process in step (2), the control points of the MJS pile construction are first determined, and then trenches are excavated. The trenches are excavated about 500 mm on both sides of the center of the jet grouting pile, and the depth is generally about 1 m. Then, the drilling rig is in place, and leveling, centering and verticality adjustments are performed. Before drilling, the mud pump is debugged to ensure that the equipment operates normally. The drilling depth of the pilot hole is slightly deeper than the designed depth by 0.5 to 1.0 m. Finally, the jet grouting is lifted. After the drill rod is lowered to the designed elevation, grouting is started. After the ground pressure reaches the designed value, backwater suction is started and the jet grouting step lifting is started. During the grouting process, close attention is paid to the ground pressure and mud discharge, and the size of the mud discharge valve is controlled in time to ensure that the ground pressure value is controlled within the design requirements and reduce the disturbance to the adjacent structures.

[0090] In the specific implementation, during the MJS construction process, the water-stop curtain within 12m of the low clearance section close to the bridge pile foundation section uses MJS with a diameter of 1200@900 and a length of 17m. In order to prevent perforation during the rotary grouting construction, the lead holes and rotary grouting need to have a certain distance, and the construction should be carried out at intervals of 3 holes or after an interval of 36h.

[0091] Part of the MJS is used for isolation and protection construction in the bidirectional section adjacent to the bridge foundation. Compared with traditional rotary jet piles, it can realize ground stress monitoring, reasonably control construction parameters, effectively control surface deformation, greatly reduce the deformation impact on the adjacent bridge foundation, and optimize the support form; the low-headroom pile foundation construction, by modifying the original circulation drilling rig and optimizing the technical measures of construction site elevation, replaces the low-headroom full-casing rotary drilling rig construction cast-in-place pile operation, under the conditions of safety and quality dual control, saves construction time and has good economic benefits; the deep foundation pit base is fully reinforced with high-pressure rotary jet piles to enhance lateral resistance, reduce pit bottom uplift and deformation of surrounding structures, and further reduce deformation of adjacent structures.

[0092] like Fig.11 As shown, in this embodiment, during the foundation pit excavation in step (6), when the excavation reaches the second support, the construction of the steel purlin and the erection of the steel support are started, and an axial force servo system is used at one end of the steel support. The stress state of the steel support system is monitored in real time through a pressure sensor, a control system and a hydraulic pump, and intelligent control of low-pressure automatic compensation and high-pressure automatic alarm is performed to adjust the axial force in real time.

[0093] In the specific implementation, during the excavation of the foundation pit, the south side foundation pit is excavated first, which serves as a temporary access road for the north side of the excavation. When the north side foundation pit begins to be excavated, the road structure construction on the south side has been completed, and the south side road is used as a temporary access road for earthwork transportation; the earthwork excavation of the foundation pits on both sides of the south and north sides is excavated from both sides to the middle, and the excavation is retreated in a stepped manner along the bottom of the foundation pits on both sides to the middle, and the long-arm excavator is used to cooperate to lift the earthwork out of the foundation pit and load it into trucks for transportation; the longitudinal slope of the foundation pit excavation is generally maintained at 1:3, the longitudinal excavation width is 4 to 6m, and the height of the excavation step should not be greater than 2m;

[0094] During the steel support erection process, excavation was carried out to 500mm below the second support, and the construction of steel purlins and the erection of steel supports began. The steel support specifications were Φ609×16mm, and the longitudinal spacing was 3 to 4m.

[0095] The steel support servo axial force system is used in foundation pit excavation to realize real-time monitoring and control of the support axial force, which solves the problem that the traditional movable head can not strictly control the deformation of the foundation pit side wall and the risk of uncontrollable safety of the surrounding environment, and has good social benefits. Lattice column nodes are added symmetrically close to the foundation pit of the bridge foundation section to enhance the overall stability of the support, better control the deformation of the retaining structure, and reduce the disturbance to the surrounding environment.

[0096] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0097] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A bored pile drilling device for tunnel construction, characterized in that: include: A support module (100), used for supporting and limiting; A drilling module (200) is used for drilling holes in cast-in-place pile construction. The drilling module (200) is arranged on a supporting module (100). The drilling module (200) comprises a sleeve (210). A connecting rod 1 (220) is arranged inside the sleeve (210). A connecting rod 2 (230) is slidably connected to the side of the connecting rod 1 (220). A connecting rod 3 (240) is slidably connected to the inner side of the sleeve (210). A drill bit 1 (221) is fixedly connected to the bottom end of the connecting rod 1 (220). A drill bit 2 (231) is fixedly connected to the bottom end of the connecting rod 2 (230) and is slidably connected to the side of the drill bit 1 (221). A drill bit 3 (241) is fixedly connected to the bottom of the side of the connecting rod 3 (240) and is slidably connected to the side of the drill bit 2 (231). The vehicle body (300) is arranged at the bottom of the supporting module (100), and the vehicle body (300) is used for walking.

2. The bored pile drilling device for tunnel construction according to claim 1, characterized in that: Two connecting grooves (250) are provided on the sides of the connecting rod 1 (220), the connecting rod 2 (230) and the connecting rod 3 (240); a connecting block (251) is slidably connected to the bottom of the inner side of the connecting groove (250); and the inner side of the sleeve (210), the connecting rod 2 (230) and the connecting rod 3 (240) are fixedly connected to the sides of two adjacent connecting blocks (251).

3. The bored pile drilling device for tunnel construction according to claim 1, characterized in that: The support module (100) comprises: A limiting rod (110) is arranged on one side of the sleeve (210), and a fixing seat (111) is fixedly connected to the side of the limiting rod (110); A sliding seat (120) is slidably connected to the top of the side of the limiting rod (110), and the inner side of the sliding seat (120) is rotatably connected to the top of the side of the sleeve (210); The driving seat (130) is fixedly connected to the bottom end of the limiting rod (110), the sleeve (210) passes through the interior of the driving seat (130), and the side of the driving seat (130) away from the drilling module (200) is fixedly connected to the limiting seat (136); Two hydraulic rods (140) are arranged on a side close to the vehicle body (300), and the top ends of the two hydraulic rods (140) are rotatably connected to the inner side surface of the fixing seat (111) through a shaft; A connecting seat (150) is arranged at the bottom end of the hydraulic rod one (140), the bottom ends of the two hydraulic rods one (140) are rotatably connected to the inner side surface of the connecting seat (150) through a shaft rod, the side surface of the limit seat (136) is rotatably connected to the inner side surface of the connecting seat (150) through a shaft rod, and two positioning rods (151) are arranged on the inner side surface of the connecting seat (150), and one end of the two positioning rods (151) is fixedly connected to the vehicle body (300); The fixed rod (160) is fixedly connected to the bottom surface of the driving seat (130), and a second hydraulic rod (161) is arranged on the inner side surface of the fixed rod (160). The output end of the second hydraulic rod (161) is transmission-connected to an abutment rod (162) which is slidably connected to the inner side surface of the fixed rod (160).

4. The bored pile drilling device for tunnel construction according to claim 3, characterized in that: A sliding groove (112) is provided on the side of the limit rod (110) corresponding to the sliding seat (120); an adjusting screw rod (113) is rotatably connected to the inner side of the sliding seat (120); a power motor (114) is fixedly connected to the top of the limit rod (110); and an output end of the power motor (114) is transmission-connected to the top of the adjusting screw rod (113); A driving motor (133) is arranged on the inner side surface of the driving seat (130); the output end of the driving motor (133) is drivingly connected to a driving shaft (134) rotatably connected to the inner side surface of the driving seat (130); the inner side surface of the driving seat (130) is rotatably connected to a driving ring (131) slidably connected to the side surface of the sleeve (210); two locking grooves (211) are arranged on the side surface of the sleeve (210); the inner side surface of the driving ring (131) is fixedly connected to two locking blocks (132) slidably connected to the inner side surfaces of adjacent locking grooves (211); the side surface of the driving ring (131) and the side surface of the driving shaft (134) are both fixedly sleeved with driving gears (135), and the two driving gears (135) are meshed for transmission.

5. The bored pile drilling device for tunnel construction according to claim 3, characterized in that: The top of the sleeve (210) is fixedly connected with an adjustment box (260) which is rotatably connected to the inner side surface of the sliding seat (120); the top surface of the adjustment box (260) is rotatably connected with a positioning box (270) which is fixedly connected to the inner side surface of the sliding seat (120); the inner side surface of the positioning box (270) is provided with a threaded rod (280) which is rotatably connected to the side surface of the adjustment box (260); the top surfaces of the connecting rod 1 (220), the connecting rod 2 (230) and the connecting rod 3 (240) are all provided with threaded holes; the side surface of the threaded rod (280) is screwed and connected with the threaded hole on the connecting rod 1 (220); The inner side surface of the adjustment box (260) is rotatably connected to two winding rods (262), and the ends of the two winding rods (262) close to each other are rotatably connected to a positioning ring (263) rotatably connected to the side surface of the threaded rod (280), and the sides of the two winding rods (262) are both wound with limiting ropes (261) extending to the inside of the sleeve (210), one limiting rope (261) passes through the inside of the connecting rod three (240) and is fixedly connected to the top surface of the connecting rod two (230), and the bottom end of the other limiting rope (261) is fixedly connected to the top surface of the connecting rod three (240).

6. The bored pile drilling device for tunnel construction according to claim 5, characterized in that: Two adjusting rods (264) are rotatably connected to the inner side surface of the adjusting box (260) corresponding to the reeling rod (262); a fixing ring (268) rotatably connected to the two adjusting rods (264) is fixedly connected to the top of the inner side surface of the adjusting box (260); a worm (265) is fixedly sleeved on the side surface of the adjusting rod (264); and a worm wheel (266) meshing with an adjacent worm (265) is fixedly sleeved on the side surface of the reeling rod (262); Two adjusting motors (273) are fixedly connected to the inner side surface of the positioning box (270) corresponding to the adjusting rod (264); the output end of the adjusting motor (273) is drivingly connected to a transmission rod (274) rotatably connected to the inner side surface of the positioning box (270); a transmission gear (275) is fixedly sleeved at the bottom of the side surface of the transmission rod (274); a connecting gear (267) is fixedly sleeved at the top of the side surface of the adjusting rod (264); a limiting ring (271) is fixedly connected to the bottom surface of the positioning box (270) and rotatably connected to the top surface of the adjusting box (260); the inner side surface of the bottom of the positioning box (270) and the side surface of the limiting ring (271) are both rotatably connected to two connecting gear rings (272); the transmission gear (275) and the connecting gear (267) located on the same side of the limiting ring (271) are both meshed with a corresponding connecting gear ring (272) for transmission.

7. The bored pile drilling device for tunnel construction according to claim 5, characterized in that: The inner side surface of the positioning box (270) is fixedly connected to a bellows (290) passing through the interior of the threaded rod (280); the bottom end of the bellows (290) is fixedly connected to a connecting tube (291); the inner bottom surface of the drill bit 1 (221) is fixedly connected to a fixed tube (222) rotatably connected to the bottom end of the connecting tube (291); the bottom of the side surface of the connecting rod 1 (220) is provided with a plurality of opening grooves 1; the top surfaces of the drill bits 2 (231) and the drill bits 3 (241) are both provided with opening grooves 2.

8. The tunnel construction method of the bored pile drilling device for tunnel construction according to claim 1, characterized in that: It includes the construction steps of surveying and setting out - construction of retaining structures - construction of column piles - pit bottom reinforcement - foundation pit dewatering - foundation pit excavation. The specific steps are as follows: Step (1) Surveying and staking out: Calculate the coordinates of the project's proposed structure points based on the control pile positions, construction drawings and related design documents, use a total station to conduct on-site construction staking out, make relevant marks, and use re-measurement to ensure measurement accuracy; Step (2) Construction of retaining structure: First, bored cast-in-place piles are constructed. A drilling device is used to drill bored piles. Then, a steel cage is hoisted into the hole. Finally, concrete is poured. If the clearance height under the bridge cannot meet the construction conditions, the drilling rig is modified by refitting the original circulating drilling rig and lowering the site elevation. The water-stop curtain within 12m of the low clearance section adjacent to the bridge pile foundation section is constructed using MJS. The water-stop curtain for the remaining sections of the bored piles is constructed using double-row triple-tube high-pressure rotary jet piles. Three rotary jet piles are used to stop water at the cold joints with other surrounding support forms. Finally, the crown beam and the first-floor concrete support are constructed. Step (3) Column pile construction: first carry out the preliminary hole-forming construction, the lattice column is processed and manufactured on site, then the steel cage and the lattice column are installed, and then concrete is poured and backfilled with sand and gravel; Step (4) pit bottom reinforcement: double-tube high-pressure jet grouting piles are used to reinforce the tunnel excavation construction area near the bridge pile foundation, and the construction process is the same as the high-pressure jet grouting pile water-stop curtain; Step (5) foundation pit dewatering: pipe well dewatering is adopted in the foundation pit, drainage wells are set up, and a dewatering well is set up every 20m. The well wall pipe adopts cement gravel filter pipe, and the bottom is overlapped with a sand settling pipe. The filter pipe is wrapped with a layer of nylon mesh. A longitudinal intercepting ditch is set around the foundation pit. At the same time, a proper amount of water level monitoring holes are set up inside and outside the foundation pit to monitor the groundwater level in the foundation pit; Step (6) foundation pit excavation: The foundation pit is excavated adjacent to the bridge foundation section, divided into north and south sides. The earthwork excavation of the foundation pits on the north and south sides is excavated from both sides to the middle, and the excavation is retreated in a stepped manner along the bottom of the foundation pits on both sides toward the middle.

9. The tunnel construction method of the bored pile drilling device for tunnel construction according to claim 8, characterized in that: During the MJS construction process in step (2), the control points of the MJS pile construction are first determined, and then trenches are excavated. The trenches are excavated about 500 mm on both sides of the center of the jet grouting pile, and the depth is generally about 1 m. Then, the drilling rig is in place, and leveling, centering and verticality adjustments are performed. Before drilling, the mud pump is debugged to ensure that the equipment operates normally. The pilot hole drilling depth is slightly deeper than the design depth by 0.5 to 1.0 m. Finally, the jet grouting is lifted. After the drill rod is lowered to the design elevation, grouting is started. After the ground pressure reaches the design value, backwater suction is started and the jet grouting step lifting is started. During the grouting process, close attention is paid to the ground soil pressure and mud discharge, and the size of the mud discharge valve is controlled in time to ensure that the ground soil pressure value is controlled within the design requirement range to reduce the disturbance to the adjacent structures.

10. The tunnel construction method of the bored pile drilling device for tunnel construction according to claim 8, characterized in that: During the excavation of the foundation pit in step (6), when the excavation reaches the second support, the construction of the steel purlin and the erection of the steel support begins. An axial force servo system is used at one end of the steel support to monitor the stress state of the steel support support system in real time through a pressure sensor, a control system and a hydraulic pump, and to perform intelligent control of low-pressure automatic compensation and high-pressure automatic alarm, so as to adjust the axial force in real time.

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