Self-propelled drilling rig and construction method thereof

Abstract

A self-propelled drilling rig includes a crawler chassis, a mast, a power head, a lifting cylinder, a rotary reducer, a drill rod disassembly device, a multi-section drill rod and a drill bit; the mast is fixedly mounted in front of the main chassis; the bottom flange ring is perpendicular to the bottom of the mast; the power head is placed on the mast guide rail; the lifting cylinder is hinged with the guide casing and the mast; the rotary reducer is fixed under the bottom flange ring; the drill rod disassembly device is fixed with the rotary reducer; the butt joint and the upper and lower joints of the drill rod are provided with joint notches; the short fork plate is placed on the pad, and the inner snap-in is inserted into the joint notch of the lower joint; the long fork plate is placed at the bottom flange ring, and the inner snap-in is inserted into the joint notch of the butt joint. The construction method includes the steps of installing the self-propelled drilling rig in place, connecting the drill rod and the drill bit, drilling into the soil, stirring and grouting, and static maintenance of the bored pile. The present invention has the characteristics of low net height, flexible movement, and convenient installation and disassembly, meets the construction needs of height-restricted areas, and improves the efficiency of bored pile construction.

Description

Technical Field

[0001] The invention belongs to the technical field of construction machinery, and in particular relates to a self-propelled drilling rig and a construction method thereof. Background Art

[0002] In the existing urban rail transit, city center building pile construction and foundation reinforcement projects, there are often structures above the construction site, high-voltage power facilities, construction under the communication line network or under the bridge, and working conditions close to existing buildings. Due to the limited construction height and surrounding environment, the drill rod connection operation is very frequent during pile foundation construction. During the drilling and mixing process of the drilling rig, the drilling tool and its auxiliary equipment often require a higher construction space. The traditional walking drilling rig cannot enter the construction site or approach the existing building due to the tall mast and large area. Therefore, in the face of such a complex surrounding environment, the measures taken by the construction company are generally to negotiate with the power grid and communication departments to temporarily cut off the power grid and communication network lines above the pile foundation construction area, and then connect the power grid and lines after the pile foundation construction is completed, which will cause great consumption of construction progress and construction costs. In the case of fruitless negotiation, the design plan of pile foundation construction or foundation treatment can only be changed, which seriously affects the construction progress and causes a lot of resource waste. Therefore, it is necessary to develop a low-headroom drilling rig and its construction method that are easy to move and easy to connect and disassemble drilling tools, so as to be suitable for the drilling rig to carry out cast-in-place pile construction and foundation reinforcement construction in areas with limited construction site height, close to existing buildings and greatly affected by the surrounding environment. Summary of the invention

[0003] The main purpose of the present invention is to overcome the shortcomings of the prior art and provide a self-propelled drilling rig and a construction method thereof which are easy to move, simple in structure, convenient to connect and disassemble, and reliable in hole formation, so as to realize quick drilling and mixing construction in construction areas with height restrictions and restricted surrounding environment, and improve the operating efficiency of cast-in-place pile construction and foundation reinforcement treatment in low-headroom areas.

[0004] The self-propelled drilling rig used by the present invention to solve the technical problem includes a main chassis, a mast, a power head, a lifting cylinder, two struts, a rotary reducer, a drill rod disassembly device, a multi-section drill rod with an upper joint and a lower joint, and a drill bit with an upper joint; wherein: the main chassis includes a chassis bracket including a front support, two upper supports, four corner supports and four side supports, four connecting rods, four extension arms and four legs; the mast includes a bottom section mast including a bottom flange ring, a mast lower support, two lower guide rails and a mast side ear seat , an upper mast with two upper guide rails; the power head includes a reduction box, an output shaft, a butt joint with a joint notch and a right-handed conical internal thread, two guide frames and two guide casings respectively located at the rear end of the reduction box; the drill pipe disassembly device includes a short fork plate with an internal bayonet, a long fork plate with an internal bayonet and a handle, and a pad with four guide blocks; the upper joint of the drill pipe includes a joint notch and a right-handed conical external thread; the lower joint of the drill pipe includes a joint notch and a right-handed conical internal thread; the upper joint of the drill bit includes a joint notch and a right-handed conical external thread;

[0005] Features:

[0006] The chassis bracket of the host chassis is a rectangular frame member; the front end support is arranged at the center of the front end of the chassis bracket; the upper support is arranged on the upper end surface of the chassis bracket in a left-right symmetrical manner; the corner supports are arranged at the four corners of the chassis bracket; the side supports are arranged in groups of two on the left and right sides of the chassis bracket; the extension arm is connected to the chassis bracket in a front and rear arrangement of two, one end of which is hingedly installed on each corner support of the chassis bracket and the other end is fixed with a support leg; the connecting rod is hingedly connected to each side support of the chassis bracket and the arm fork seat of each extension arm;

[0007] The mast is fixedly mounted in front of the chassis of the main engine, and is hingedly connected to the front end support of the chassis bracket through the lower mast support of the bottom mast; the upper mast is fixedly mounted above the bottom mast; after the bottom mast and the upper mast are butt-jointed, their lower guide rails and upper guide rails form the guide rails of the mast; the bottom flange ring of the bottom mast is vertically arranged at its bottom;

[0008] The support rods are arranged on two side surfaces of the bottom mast section and are respectively hingedly connected to the side supports of the bottom mast section and the two upper supports of the chassis bracket;

[0009] The power head is placed in front of the mast, and is placed on two guide rails of the mast through two guide frames of the reduction box; the guide frames of the power head are fixedly mounted on the upper left and right sides of the rear side of the reduction box; the guide casings are fixedly mounted on the outer sides of the two guide frames respectively; the butt joint is fixedly mounted on the lower end of the output shaft of the power head; multiple sections of drill rods and drill bits are sequentially connected below the butt joint, and during the forward rotation of the power head, the upper joint of the drill rod and the butt joint, the lower joint of the upper section of the drill rod and the upper joint of the lower section of the drill rod, until the last section of the drill rod and the external drill bit are locked; the power head is operated to descend along the two guide rails of the mast, and the multiple sections of drill rods and drill bits connected to the butt joint sequentially pass through the bottom flange ring of the bottom section of the mast, the inner cavity of the rotary reducer, and the through hole of the pad, and then enter the bottom layer and drill to the designed hole depth;

[0010] The lifting cylinders are respectively arranged in the form of two guide sleeves passing through the power head, and the cylinder ends and piston rods thereof are respectively hingedly installed with the bottom of the guide sleeves and the mast side ear seats on both sides of the bottom mast;

[0011] The slewing reducer is fixedly mounted on the lower end surface of the bottom flange ring of the bottom section of the mast;

[0012] The backing plate of the drill rod disassembly device is fixed on the rotary circle of the lower end surface of the rotary reducer, and the four guide blocks of the backing plate are located in the inner cavity of the rotary reducer; the four guide blocks of the backing plate are arranged in a rectangular manner on the end surface outside the through hole;

[0013] After the multi-section drill pipe reaches the required drilling depth along with the drill bit, the power head is closed to stop the multi-section drill pipe from rotating forward, and the inner snap-in of the short fork plate is aligned with the joint notch of the upper joint of the lower section of the drill pipe and inserted, and after passing through the inner cavity of the rotary reducer, it is placed in the area surrounded by four guide blocks on the pad to lock the lower section of the drill pipe; the inner snap-in of the long fork plate is aligned with the joint notch of the docking joint of the power head and inserted, and the handle is placed on the upper end surface of the bottom flange ring of the bottom section of the mast to lock the docking joint;

[0014] The extension arm has two or three extension arm fork seats;

[0015] The lifting cylinder adopts a multi-section telescopic hydraulic cylinder type;

[0016] The thickness of the short fork plate is greater than the height of the four guide blocks of the pad.

[0017] In addition, the present invention provides a construction method of the self-propelled drilling rig, comprising the following steps:

[0018] 1) Install the self-propelled drilling rig in place, a) clean up the construction site, ensure that the construction area is flat and avoid high-voltage cables; b) move the main chassis with the mast, slewing reducer and pad installed to the construction area, use a crane to vertically install two struts, and install the power head and lifting cylinder in front of the mast; connect the hydraulic hoses of the extension cylinder and lifting cylinder of the outrigger, connect the power cable of the power head, and firmly connect the grouting pipeline of the external grouting system to the grouting port of the power head; c) operate the self-propelled drilling rig to the drilling station, open the extension arm of the main chassis outward, and lock it with the main chassis through various connecting rods; operate the extension cylinder of the outrigger to support it on the ground;

[0019] 2) The drill pipe and drill bit of the self-propelled drilling rig are connected as follows: a) Operate the lifting cylinder to move the power head upward along the two guide rails of the mast, lift the drill pipe to the docking joint at the lower end of the output shaft of the power head, operate the power head to rotate forward, and the right-handed conical external thread of the upper joint of the first section of the drill pipe enters the right-handed conical internal thread of the docking joint, completing the fixed connection between the first section of the drill pipe and the output shaft of the power head; b) Operate the lifting cylinder to continue to lift the power head, lift the drill bit to the bottom of the lower joint of the first section of the drill pipe, operate the power head to rotate forward, and complete the fixed connection between the drill bit and the first section of the drill pipe above;

[0020] 3) The self-propelled drilling rig drills into the soil. a) Operate the power head and the lifting cylinder to make the power head and the first section of the drill pipe and the drill bit connected to it rotate forward along the mast while descending, until the first section of the drill pipe and the drill bit pass through the bottom flange ring of the bottom section of the mast, the inner cavity of the rotary reducer, and the through hole of the pad in sequence and then enter the soil layer for drilling; b) Close the power head to stop the first section of the drill pipe and the drill bit from rotating forward, pass the short fork plate through the inner cavity of the rotary reducer into the area surrounded by the four guide blocks on the pad, and align the inner snap-in of the short fork plate with the upper connection of the first section of the drill pipe. Insert and lock the long fork plate into the joint notch of the power head; place the long fork plate on the end face of the bottom flange ring of the bottom section of the mast, align the inner snap-in of the long fork plate with the joint notch of the power head, insert and lock; c) operate the slewing reducer to rotate in the opposite direction, the first section of the drill pipe rotates in the opposite direction with the slewing reducer, and the long fork plate rotates with the butt joint until its handle reaches the mast and stops; the reverse rotation of the slewing reducer drives the short fork plate and the conical external thread of the upper joint of the first section of the drill pipe to loosen from the conical internal thread of the butt joint, and the long fork plate is pulled out from the joint notch of the butt joint, Operate the power head upward along the mast, and the butt joint is completely separated from the first section of drill pipe along with the power head, leaving the rotary reducer and the bottom flange ring of the bottom mast, and stays at a certain height; d) Lift the second section of drill pipe to be connected and erect it to the bottom of the power head, and align the upper joint and lower joint of the second section of drill pipe with the butt joint and the upper joint of the first section of drill pipe below respectively. Operate the power head while rotating forward and downward, and the conical internal thread of the butt joint enters the conical external thread of the upper joint of the added section of drill pipe and the conical external thread of the second section of drill pipe. After the conical internal thread of the lower joint enters the conical external thread of the upper joint of the first drill pipe below and is completely tightened, the second drill pipe is connected and the short fork plate is removed from the pad; e) Operate the power head and the lifting cylinder to make the power head and the two drill pipes and drill bits connected to it rotate forward while going down into the soil to drill and dig, until the second drill pipe connected passes through the bottom flange ring of the bottom mast, the inner cavity of the rotary reducer, and the through hole of the pad in sequence and enters the soil layer. Through the continuous drilling and cutting of the connected drill pipes and drill bits, the hole depth required by the design is finally reached;

[0021] 4) Self-propelled drilling rig mixing grouting: a) Operate the power head and lifting cylinder to make the power head and its connected multi-section drill pipe and drill bit rotate forward and move upward. During the lifting process of the drill bit, start the external grouting system to inject cement slurry into the hole through the grouting pipeline, the output shaft of the power head, the multi-section drill pipe and the drill bit, and fully mix it with the in-situ soil; b) When the first section of the drill pipe fixed to the docking joint of the power head is exposed in the hole, turn off the power head and the external grouting system, and remove the section of the drill pipe according to step 3) b) and c), and so on until all the drill pipes and drill bits are removed from the hole;

[0022] 5) For static curing of bored piles, the self-propelled drilling rig is operated to leave the drilling station. The mixture of cement slurry and in-situ soil in the drilled hole is allowed to stand and cure as required to form a cement bored pile.

[0023] The present invention may also be that in the step 4), after the first section of drill pipe is removed from under the power head, the power head and the lifting cylinder are operated to move the power head down to the second section of drill pipe, and the docking joint at the output shaft is fixedly connected to the upper joint of the second section of drill pipe below; the power head and the lifting cylinder are operated again to make the power head and the second and above sections of drill pipe and drill bit connected thereto rotate forward while moving upward, and while the second and above sections of drill pipe and drill bit are rotating and lifted up, the external grouting system is operated to inject cement slurry into the hole until the second and above sections of drill pipe and drill bit are all lifted out of the ground; in this way, the lifting and disassembly of all drill pipes and drill bits are completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the self-propelled drilling rig of the present invention;

[0025] Figure 2 yes Figure 1 A top view of

[0026] Figure 3 yes Figure 1 Middle AA section view;

[0027] Figure 4 yes Figure 3 Middle BB section view;

[0028] Figure 5 It is a structural schematic diagram of a long fork plate of a drill rod disassembly device in a self-propelled drilling rig of the present invention;

[0029] Figure 6 It is a structural schematic diagram of a power head in a self-propelled drilling rig of the present invention;

[0030] Figure 7 yes Figure 6 Top view of the . DETAILED DESCRIPTION

[0031] Combined with Figure 1-7 , the self-propelled drilling rig of the present invention is further explained.

[0032] A self-propelled drilling rig comprises a mainframe chassis 1, a mast 2, a power head 3, a lifting cylinder 4, two support rods 5, a rotary reducer 6, a drill rod disassembly device, a multi-section drill rod 8 with an upper joint 82 and a lower joint 83, and a drill bit 9 with the upper joint 82. The mainframe chassis 1 comprises a chassis bracket 11 comprising a front end support 112, two upper supports 115, four corner supports 113 and four side supports 114, four connecting rods 12, four extension arms 13 and four legs 14; the mast 2 comprises a bottom section mast 21 comprising a bottom flange ring 211, a mast lower support 212, two lower guide rails 213 and a mast side ear seat 215, and a bottom section mast 21 comprising two upper guide rails. 213' of the upper mast 21'; the power head 3 includes a reduction box 31, an output shaft 32, a joint 33 with a joint notch 331, two guide frames 34 and two guide casings 35 respectively located at the rear end of the reduction box; the drill rod disassembly device includes a short fork plate 71 with an inner bayonet 712, a long fork plate 72 with a handle 725 of the inner bayonet 712 and a pad 73 with four guide blocks 731; the upper joint 82 of the drill rod 8 includes a joint notch 331 and a right-handed conical external thread; the lower joint 83 of the drill rod 8 includes a joint notch 331 and a right-handed conical internal thread; the upper joint 82 of the drill bit 9 includes a joint notch 331 and a right-handed conical external thread; wherein:

[0033] The chassis bracket 11 of the main chassis 1 is a rectangular frame member; the front end support 112 is arranged at the center of the front end of the chassis bracket 11; the upper support 115 is arranged on the upper end surface of the chassis bracket 11 in a left-right symmetrical manner; the corner supports 113 are arranged at the four corners of the chassis bracket 11; the side supports 114 are arranged in groups of two on the left and right sides of the chassis bracket 11; the extension arm 13 is connected to the chassis bracket 11 in a front and rear arrangement of two, one end of which is hingedly mounted on each corner support 113 of the chassis bracket 11, and the other end is fixed with the support leg 14; by adjusting the extension length of each support leg 14, the horizontality requirements of the main chassis 1 and its chassis bracket 11 are met, thereby improving the verticality of the drilling pile of the drilling rig and ensuring the construction quality of the cast-in-place pile and foundation reinforcement treatment. The connecting rod 12 is respectively connected to the side supports 114 of the chassis bracket 11 and the arm fork 131 of each extension arm 13 by hinge connection; two or three arm fork 131 of the extension arm 13 are provided. In this way, when each extension arm 13 is extended outward along the side supports 114 of the chassis bracket 11, the connecting rod 12 is hingedly installed with the arm fork 131 at different positions on the extension arm 13, so as to adapt to different surrounding site spaces and meet the chassis bracket 11 of the main chassis 1 to meet the whole machine stability requirements of the self-propelled drilling rig.

[0034] The mast 2 is fixedly mounted in front of the main engine chassis 1, and is hingedly connected to the front end support 112 of the chassis bracket 11 through the lower mast support 212 of its bottom mast section 21; the upper mast 21' is fixedly mounted above the bottom mast section 21; after the bottom mast section 21 and the upper mast 21' are docked, their lower guide rails 213 and upper guide rails 213' constitute the guide rails of the mast 2; the bottom flange ring 211 of the bottom mast section 21 is vertically arranged at its bottom.

[0035] The support rod 5 is arranged on two side surfaces of the bottom mast section 21, and is respectively hingedly connected with the side support 25 of the bottom mast section 21 and the two upper supports 115 of the chassis bracket 11. Generally, after the bottom mast section 21 of the mast 2 is erected backward along the front end support 112 at the center of the front end of the chassis bracket 11, the two ends of the support rod 5 are respectively hingedly connected with the side support 25 of the mast 2 and the upper support 115 of the chassis bracket 11 and then locked.

[0036] The power head 3 is placed in front of the mast 2, and is placed on two guide rails of the mast 2 through two guide frames 34 of the reduction box 31; the guide frames 34 of the power head 3 are fixedly mounted on the upper left and right sides of the rear side of the reduction box 31; the guide casings 35 are respectively fixedly mounted on the outer sides of the two guide frames 34; the docking joint 33 is fixedly mounted on the lower end of the output shaft 32 of the power head; multiple sections of drill rods 8 and drill bits 9 are sequentially connected below the docking joint 33, and the power head 3 is rotated in the forward direction. The upper joint 82 of the drill rod 8 and the butt joint 33, the lower joint 83 of the upper section of the drill rod 8 and the upper joint 82 of the lower section of the drill rod 8, until the last section of the drill rod 8 and the drill bit 9 are locked; the power head 3 is operated to move downward along the two guide rails of the mast 2, and the multiple sections of drill rods 8 and drill bits 9 connected by the butt joints 33 successively pass through the bottom flange ring 211 of the bottom section of the mast 21, the inner cavity of the rotary reducer 6, and the through hole 732 of the pad, and then enter the bottom layer downward to drill to the designed hole depth.

[0037] The lifting cylinder 4 is respectively arranged in the form of two guide sleeves 35 passing through the power head 3, and its cylinder end and piston rod are respectively hingedly installed with the bottom of the guide sleeve 35 and the mast side ear seats 215 on both sides of the bottom mast 21. The lifting cylinder 4 adopts a multi-section telescopic hydraulic cylinder type. In this way, the travel requirement of the power head moving up and down along the guide rail of the mast is effectively met.

[0038] The rotary reducer 6 is fixedly mounted on the lower end surface of the bottom flange ring 211 of the bottom mast section 21 of the mast 2 .

[0039] The pad 73 of the drill rod disassembly device is fixed on the rotary circle of the lower end surface of the rotary reducer 6, and the four guide blocks 731 of the pad are located in the inner cavity of the rotary reducer 6; when the rotary reducer 6 is driven by external power, the pad 73 rotates with the rotary circle of the rotary reducer 6. The four guide blocks 731 of the pad 73 are arranged in a rectangular manner on the end surface outside the through hole; the short fork plate 71 passes through the inner cavity of the rotary reducer 6 and is placed in the area surrounded by the four guide blocks 731 on the pad 73; the thickness of the short fork plate 71 is greater than the height of the four guide blocks 731 of the pad 73. The long fork plate 72 is placed at the upper end surface of the bottom flange ring 211 of the bottom mast 21.

[0040] After the multi-section drill rod 8 reaches the required drilling depth along with the drill bit 9, the power head 3 is closed to stop the forward rotation of the multi-section drill rod 8, and the inner snap-in 712 of the short fork plate 71 is aligned with the joint notch 331 of the upper joint 82 of the lower section of the drill rod 8 and inserted therein, and after passing through the inner cavity of the rotary reducer 6, it is placed in the area surrounded by the four guide blocks 731 on the pad 73 to lock the lower section of the drill rod 8; the inner snap-in 712 of the long fork plate 72 is aligned with the joint notch 331 of the docking joint 33 of the power head 3 and inserted therein, and the handle 725 is placed on the upper end surface of the bottom flange ring 211 of the bottom section mast 21 of the mast 2 to lock the docking joint 33.

[0041] Combined with Figure 1-7 , the construction method using a self-propelled drilling rig includes the following steps:

[0042] Step 1: Install the self-propelled drilling rig

[0043] a) Clean up the construction site, ensure that the construction area is flat and avoid high-voltage cables; b) Move the main chassis 1 with the mast 2, slewing reducer 6 and pad 73 installed to the construction area, use a crane to vertically install two support rods 5, and install the power head 3 and lifting cylinder 4 in front of the mast 2; connect the hydraulic hoses of the extension cylinder and lifting cylinder 4 of the outrigger 14, connect the power cable of the power head 3, and firmly connect the grouting pipeline of the external grouting system to the grouting port of the power head 3; c) Operate the self-propelled drilling rig to the drilling station, open the extension arm 13 of the main chassis 1 outward, and lock it with the main chassis 1 through each connecting rod 12; operate the extension cylinder of the outrigger 14 to support it on the ground.

[0044] Step 2: Drill rod and drill bit connection of self-propelled drilling rig

[0045] a) Operate the lifting cylinder 4 to make the power head 3 move upward along the two guide rails of the mast 2, and hoist the first section of drill pipe 8 to the docking joint 33 at the lower end of the output shaft 32 of the power head 3, operate the power head 3 to rotate forward, and the right-handed conical external thread of the upper joint 82 of the first section of drill pipe 8 enters the right-handed conical internal thread of the docking joint 33, completing the fixed connection between the first section of drill pipe 8 and the output shaft 32 of the power head 3; b) Operate the lifting cylinder 4 to continue to lift the power head 3, and hoist the drill bit 9 to the bottom of the lower joint 83 of the first section of drill pipe 8, and operate the power head 3 to rotate forward to complete the fixed connection between the drill bit 9 and the upper first section of drill pipe 8.

[0046] Step 3: Self-propelled drilling rig drilling into the soil

[0047] a) Operate the power head 3 and the lifting cylinder 4 to make the power head 3 and the first section of the drill rod 8 and the drill bit 9 connected thereto rotate forwardly while descending along the mast 2, until the first section of the drill rod 8 and the drill bit successively pass through the bottom flange ring 211 of the bottom section of the mast 21, the inner cavity of the rotary reducer 6, and the through hole 732 of the pad to enter the soil layer for drilling; b) Close the power head 3 to stop the first section of the drill rod 8 and the drill bit 9 from rotating forwardly, and move the short fork plate 71 through the inner cavity of the rotary reducer 6 into the area surrounded by the four guide blocks 731 on the pad 73, and align the inner snap-in 712 of the short fork plate with the joint notch 331 of the upper joint 82 of the first section of the drill rod 8 and insert it The long fork plate 72 is placed on the end face of the bottom flange ring 211 of the bottom mast section 21 of the mast 2, and the inner bayonet 712 of the long fork plate is aligned with the joint notch 331 of the docking joint 33 of the power head 3 and inserted and locked; c) the rotary reducer 6 is operated to rotate in the opposite direction, and the first section drill rod 8 rotates in the opposite direction with the rotary reducer 6, and the long fork plate 72 rotates with the docking joint 33 until the handle 725 reaches the mast 2 and stops; the rotary reducer 6 rotates in the opposite direction to drive the short fork plate 71 and the conical external thread of the upper joint 82 of the first section drill rod 8 to loosen from the conical internal thread of the docking joint 33, and the long fork plate 72 is removed from the joint notch 33 of the docking joint 33. 31, and the power head 3 is operated to move upward along the mast 2, so that the butt joint 33 is completely disconnected from the first drill pipe 8, and leaves the rotary reducer 6 and the bottom flange ring 211 of the bottom mast 21, and stays at a certain height position; d) The second drill pipe 8 to be connected is hoisted and erected to the bottom of the power head 3, and the upper joint 82 and the lower joint 83 of the second drill pipe are respectively aligned with the butt joint 33 and the upper joint 82 of the first drill pipe 8 below, and the power head 3 is operated to rotate downward in the forward direction, and the conical internal thread of the butt joint 33 enters the conical external thread of the upper joint 82 of the second drill pipe 8, and the second drill pipe is connected. After the conical internal thread of the lower joint 83 of 8 enters the conical external thread of the upper joint 82 of the first drill rod 8 below and is completely tightened, the second drill rod 8 is connected and the short fork plate 71 is removed from the pad 73; e) the power head 3 and the lifting cylinder 4 are operated to make the power head 3 and the connected second drill rod 8 and drill bit 9 rotate forward while descending into the soil for drilling, until the connected second drill rod 8 passes through the bottom flange ring 211 of the bottom mast 21, the inner cavity of the rotary reducer 6, and the pad through hole 732 in sequence and enters the soil layer, and the drilling and cutting by continuously connecting the drill rod 8 and the drill bit 9 finally reaches the designed hole depth.

[0048] Step 4: Self-propelled drilling rig mixing grouting

[0049] a) Operate the lifting cylinder 4 of the power head 3 to make the power head 3 and the connected multi-section drill rod 8 and drill bit 9 rotate forward and move upward. During the lifting process of the drill bit 9, start the external grouting system to inject cement slurry into the hole through the grouting pipeline, the output shaft 32 of the power head 3, the multi-section drill rod 8 and the drill bit 9, and fully mix them with the in-situ soil; b) When the first section of the drill rod 8 fixed to the docking joint 33 of the power head 3 is exposed in the hole, turn off the power head 3 and the external grouting system, and remove the first section of the drill rod according to step 3) b) and c), and so on, until all the drill rods 8 and drill bits 9 are taken out of the hole.

[0050] After the first section of drill pipe 8 is removed from under the power head 3, the power head 3 and the lifting cylinder 4 are operated to make the power head 3 move downward to the second section of drill pipe 8, and the docking joint 33 at the output shaft 32 is fixedly connected to the upper joint 82 of the second section of drill pipe 8 below; the power head 3 and the lifting cylinder 4 are operated again to make the power head 3 and the second and above sections of drill pipe 8 and drill bit 9 connected thereto move upward while rotating in the forward direction, and while the second and above sections of drill pipe 8 and drill bit 9 are rotating and lifted up, the external grouting system is operated to inject cement slurry into the hole until the second and above sections of drill pipe 8 and drill bit 9 are all lifted out of the ground; in this way, the lifting and disassembly of all drill pipes 8 and drill bits are completed.

[0051] Step 5: Static maintenance of cast-in-place piles

[0052] The self-propelled drilling rig is operated to leave the drilling station, and the mixture of cement slurry and in-situ soil in the drilled hole is left to stand and cure as required to form a cement cast-in-place pile.

[0053] The self-propelled drilling rig and the construction method thereof of the present invention have the characteristics of convenient mobility, simple structure, convenient docking and disassembly, and reliable hole formation. They can realize quick drilling and mixing construction in construction areas with height restrictions and restricted surrounding environments, and improve the operating efficiency of cast-in-place pile construction and foundation reinforcement treatment in low-headroom areas.

[0054] Various changes and improvements may be made to the present invention without departing from the overall concept of the present invention. However, as long as they are identical or equivalent to the present invention, they also fall within the protection scope of the present invention.

Claims

1. A self-propelled drilling rig, comprising a main chassis (1), a mast (2), a power head (3), a lifting cylinder (4), two support rods (5), a rotary reducer (6), a drill rod disassembly device, a multi-section drill rod (8) having an upper joint (82) and a lower joint (83), and a drill bit (9) having an upper joint (82), wherein: The main chassis (1) comprises a chassis bracket (11) including a front support (112), two upper supports (115), four corner supports (113) and four side supports (114), four connecting rods (12), four extension arms (13) and four legs (14); The mast (2) comprises a bottom mast section (21) including a bottom flange ring (211), a mast lower support (212), two lower guide rails (213) and mast side ear seats (215), and an upper mast (21') including two upper guide rails (213'); The power head (3) comprises a reduction box (31), an output shaft (32), a joint notch (331), a right-handed conical external thread joint (33), two guide frames (34) and two guide sleeves (35) respectively located at the rear end of the reduction box; The drill rod disassembly device comprises a short fork plate (71) including an inner bayonet (712), a long fork plate (72) including an inner bayonet (712) and a handle (725), and a pad (73) including four guide blocks (731); The upper joint (82) of the drill rod (8) comprises a joint notch (331) and a right-handed conical external thread; the lower joint (83) of the drill rod (8) comprises a joint notch (331) and a right-handed conical internal thread; The upper joint (82) of the drill bit (9) comprises a joint notch (331) and a right-handed conical external thread; Features: The chassis support (11) of the main chassis (1) is a rectangular frame member; the front end support (112) is arranged at the center of the front end of the chassis support (11); the upper support (115) is arranged on the upper end surface of the chassis support (11) in a bilaterally symmetrical manner; the corner supports (113) are arranged at the four corners of the chassis support (11); the side supports (114) are arranged in groups of two on the left and right sides of the chassis support (11); the extension arm (13) is connected to the chassis support (11) in a front and rear arrangement of two, one end of which is hingedly mounted on each corner support (113) of the chassis support (11) and the other end is fixedly mounted on the support leg (14); the connecting rod (12) is hingedly connected to each side support (114) of the chassis support (11) and the extension arm fork (131) of each extension arm (13); The mast (2) is fixedly mounted in front of the main engine chassis (1) and is hingedly connected to the front end support (112) of the chassis bracket (11) through the lower mast support (212) of the bottom mast (21); the upper mast (21') is fixedly mounted above the bottom mast (21); after the bottom mast (21) and the upper mast (21') are butt-jointed, their lower guide rails (213) and upper guide rails (213') form the guide rails of the mast (2); the bottom flange ring (211) of the bottom mast (21) is vertically arranged at its bottom; The support rod (5) is arranged on two side surfaces of the bottom mast (21), and is respectively hingedly connected to the side support (25) of the bottom mast (21) and the two upper supports (115) of the chassis bracket (11); The power head (3) is placed in front of the mast (2) and is respectively placed on two guide rails of the mast (2) through two guide frames (34) of the reduction box (31); the guide frames (34) of the power head (3) are fixedly mounted on the upper left and right sides of the rear side of the reduction box (31); the guide casings (35) are respectively fixedly mounted on the outer sides of the two guide frames (34); the butt joint (33) is fixedly mounted on the lower end of the output shaft (32) of the power head; a plurality of drill rods (8) and a drill bit (9) are sequentially connected below the butt joint (33), and the drill rods are moved in the forward rotation process of the power head (3). The upper joint (82) of the drill rod (8) and the butt joint (33), the lower joint (83) of the upper drill rod (8) and the upper joint (82) of the lower drill rod (8), until the last drill rod (8) and the drill bit (9) are locked; the power head (3) is operated to move downward along the two guide rails of the mast (2), and the multiple sections of drill rods (8) and the drill bit (9) connected to the butt joint (33) pass through the bottom flange ring (211) of the bottom mast (21), the inner cavity of the rotary reducer (6), the through hole (732) of the pad, and then enter the bottom layer and drill to the hole depth required by the design; The lifting cylinder (4) is respectively arranged in the form of two guide sleeves (35) passing through the power head (3), and its cylinder end and piston rod are respectively hingedly installed with the bottom of the guide sleeve (35) and the mast side ear seats (215) on both sides of the bottom mast (21); The slewing reducer (6) is fixedly mounted on the lower end surface of the bottom flange ring (211) of the bottom mast section (21) of the mast (2); The backing plate (73) of the drill rod disassembly device is fixedly mounted on the rotary circle of the lower end surface of the rotary reducer (6), and the four guide blocks (731) of the backing plate are located in the inner cavity of the rotary reducer (6); the four guide blocks (731) of the backing plate (73) are arranged in a rectangular manner on the end surface outside the through hole thereof; After the multi-section drill rod (8) reaches the required drilling depth along with the drill bit (9), the power head (3) is closed to stop the multi-section drill rod (8) from rotating forward, and the inner snap-in opening (712) of the short fork plate (71) is aligned with the joint notch (331) of the upper joint (82) of the lower section drill rod (8) and inserted, and after passing through the inner cavity of the rotary reducer (6), it is placed in the area surrounded by four guide blocks (731) on the pad (73) to lock the lower section drill rod (8); the inner snap-in opening (712) of the long fork plate (72) is aligned with the joint notch (331) of the docking joint (33) of the power head (3) and inserted, and the handle (725) is placed on the upper end surface of the bottom flange ring (211) of the bottom mast (21) of the mast (2) to lock the docking joint (33); Two or three extension arm fork seats (131) of the extension arm (13) are provided; The lifting cylinder (4) is a multi-section telescopic hydraulic cylinder; The thickness of the short fork plate (71) is greater than the height of the four guide blocks (731) of the pad plate (73).

2. A construction method using the self-propelled drilling rig according to any one of claims 1, comprising the following steps: 1) Self-propelled drilling rig is installed in place a) Clean up the construction site, ensure that the construction area is flat and away from high-voltage cables; b) moving the main engine chassis (1) on which the mast (2), the slewing reducer (6) and the pad (73) are installed to the construction area, using a crane to vertically erect the mast (2) and then install two support rods (5), installing a power head (3) and a lifting cylinder (4) in front of the mast (2); connecting the hydraulic hoses of the extension cylinder and the lifting cylinder (4) of the outrigger (14), connecting the power cable of the power head (3), and firmly connecting the grouting pipeline of the external grouting system to the grouting port of the power head (3); c) operating the self-propelled drilling rig to move to the drilling station, opening the extension arm (13) of the main chassis (1) outward, and locking the extension arm (13) with the main chassis (1) through the connecting rods (12); operating the extension cylinder of the outrigger (14) to support the ground; 2) Drill rod and drill bit connection of self-propelled drilling rig a) operating the lifting cylinder (4) to move the power head (3) upward along the two guide rails of the mast (2), hoisting the first section of drill rod (8) to the docking joint (33) at the lower end of the output shaft (32) of the power head (3), operating the power head (3) to rotate forward, so that the right-handed conical external thread of the upper joint (82) of the first section of drill rod (8) enters the right-handed conical internal thread of the docking joint (33), completing the fixed connection between the first section of drill rod (8) and the output shaft (32) of the power head (3); b) operating the lifting cylinder (4) to continue lifting the power head (3), lifting the drill bit (9) to below the lower joint (83) of the first section of the drill rod (8), and operating the power head (3) to rotate forward to complete the fixed connection between the drill bit (9) and the first section of the drill rod (8); 3) Self-propelled drilling rig drilling a) operating the power head (3) and the lifting cylinder (4) to make the power head (3) and the first drill rod (8) and the drill bit connected thereto rotate forward and downward along the mast (2) until the first drill rod (8) and the drill bit (9) successively pass through the bottom flange ring (211) of the bottom mast (21), the inner cavity of the rotary reducer (6), and the through hole (732) of the pad and then enter the soil layer for drilling; b) closing the power head (3) to stop the first section of the drill rod (8) and the drill bit from rotating forward, inserting the short fork plate (71) through the inner cavity of the rotary reducer (6) into the area surrounded by the four guide blocks (731) on the pad (73), aligning the inner snap-in opening (712) of the short fork plate with the joint notch (331) of the upper joint (82) of the first section of the drill rod (8), inserting and locking; placing the long fork plate (72) on the end surface of the bottom flange ring (211) of the bottom section of the mast (2), aligning the inner snap-in opening (712) of the long fork plate with the joint notch (331) of the butt joint (33) of the power head (3), inserting and locking; c) operating the rotary reducer (6) to rotate in the reverse direction, the first section of the drill pipe (8) rotates in the reverse direction along with the rotary reducer (6), and the long fork plate (72) rotates along with the docking joint (33) until its handle (725) reaches the mast (2) and stops; the rotary reducer (6) rotates in the reverse direction to drive the short fork plate (71) and the conical external thread of the upper joint (82) of the first section of the drill pipe (8) to loosen from the conical internal thread of the docking joint (33), and the long fork plate (72) is pulled out from the joint notch (331) of the docking joint (33), and the power head (3) is operated to move upward along the mast (2), and the docking joint (33) is completely separated from the first section of the drill pipe (8) along with the power head (3), leaving the rotary reducer (6) and the bottom flange ring (211) of the bottom section of the mast (21), and stays at a certain height position; d) The second drill pipe section (8) to be connected is hoisted and erected to the bottom of the power head (3), and the upper joint (82) and the lower joint (83) of the second drill pipe section are respectively aligned with the butt joint (33) and the upper joint (82) of the first drill pipe section (8) below, and the power head (3) is operated to rotate forward while descending, and the conical internal thread of the butt joint (33) enters the conical external thread of the upper joint (82) of the second drill pipe section (8) to be connected, and the conical internal thread of the lower joint (83) of the second drill pipe section (8) to be connected enters the conical external thread of the upper joint (82) of the first drill pipe section (8) below, and after they are completely tightened, the connection of the second drill pipe section (8) is completed, and the short fork plate (71) is removed from the pad (73); e) operating the power head (3) and the lifting cylinder (4) so ​​that the power head (3) and the two drill rods (8) and the drill bit (9) connected thereto rotate forwardly while descending into the soil for drilling and excavation, until the second drill rod (8) connected thereto passes through the bottom flange ring (211) of the bottom mast (21), the inner cavity of the rotary reducer (6), and the through hole (732) of the pad in sequence and enters the soil layer, and the drilling and cutting are performed by continuously connecting the drill rods (8) and the drill bit (9) to finally reach the hole depth required by the design; 4) Self-propelled drilling rig mixing grouting a) operating the power head (3) and the lifting cylinder (4) so ​​that the power head (3) and the connected multi-section drill rod (8) and the drill bit (9) rotate in the forward direction while moving upward, and in the process of lifting the drill bit (9), starting the external grouting system to inject cement slurry into the hole through the grouting pipeline, the output shaft (32) of the power head (3), the multi-section drill rod (8) and the drill bit (9) to fully mix with the in-situ soil; b) When the first section of the drill rod (8) fixed to the butt joint (33) of the power head (3) is exposed from the hole, the power head (3) and the external grouting system are turned off, and the first section of the drill rod (8) is removed according to steps b) and c) in step 3), and this is repeated until all the drill rods (8) and the drill bit (9) are removed from the hole; 5) Static maintenance of cast-in-place piles The self-propelled drilling rig is operated to leave the drilling station, and the mixture of cement slurry and in-situ soil in the drilled hole is left to stand and cure as required to form a cement cast-in-place pile.

3. The construction method of the self-propelled drilling rig according to claim 2 is characterized in that In the step 4), after the first section of the drill pipe (8) is removed from the power head (3), the power head (3) and the lifting cylinder (4) are operated to move the power head (3) downward to the second section of the drill pipe (8), and the butt joint (33) at the output shaft (32) is fixedly connected to the upper joint (82) of the second section of the drill pipe (8) below; the power head (3) and the lifting cylinder (4) are operated again to make the power head (3) and the second section of the drill pipe (8) and the drill bit connected thereto rotate forward while moving upward, and while the second section of the drill pipe (8) and the drill bit are rotating and lifted, the external grouting system is operated to inject cement slurry into the hole until the second section of the drill pipe (8) and the drill bit (9) are all lifted out of the ground; in this way, the lifting and disassembly of all the drill pipes (8) and the drill bits are completed.

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