Patent Publication Number: US-2022228440-A1

Title: Square pile construction method and equipment of a rotary drilling rig

Description:
TECHNICAL FIELD 
     The present invention belongs to the technical field of engineering construction, and particularly relates to a square pile construction method and equipment of a rotary drilling rig. 
     BACKGROUND 
     With the continuous development of social economy in our country, the investment in national infrastructure construction is now more inclined to the central and western regions, especially the mountainous and dangerous areas such as Yunnan-Guizhou Plateau, Panxi Plateau and Qinghai-Tibet Plateau. National infrastructure projects to be built or being built such as multiple expressways (e.g., Sichuan Riverside Expressway, Lexi Expressway, etc.) or high-speed railways (e.g., Sichuan-Tibet railway, etc.) are located in many earthquake zones with high mountains and precipitous paths, which are very likely to suffer from geological disasters such as mountain collapse and debris flow. Thus, requirements for border support of these infrastructure projects are relatively high, and more design elements of square supporting slide-resistant piles are added to the construction drawing design. 
     The designed aperture of square supporting piles is relatively large. At present, most of the piles are made by manual hole digging, and few are made by mechanical drilling. Due to the limitation of related machines and technologies, the construction quality and efficiency are generally unsatisfactory. 
     Meanwhile, manual hole digging has at least the following disadvantages: 1. high risk factor and high cost of safety protection; 2. large loss of retaining wall materials; 3. extremely low construction efficiency and high work efficiency cost; 4. excessively high comprehensive cost of manual hole digging construction (including cost of manual hole digging, cost of electricity, cost of retaining wall material, cost of retaining wall template, cost of safety measures, work efficiency cost caused by low labor efficiency, etc.). 
     SUMMARY 
     An objective of the present invention is to provide a square pile construction method and equipment of a rotary drilling rig. 
     In order to achieve the above objective of the present invention, a technical solution adopted by the present invention is to provide a square pile construction method of a rotary drilling rig, which comprises the following steps: 
     S1: site leveling; S2: surveying and setting out; S3: creating concrete retaining wall of wellhead; S4: putting the drilling rig in place; S5: adjusting the verticality of the drilling rig; S6: lead hole drilling: setting lead holes in the retaining wall, and performing drilling based on the lead holes to form square pile drilled holes; S7: reamed hole drilling: continuing to drill reamed holes on the basis of lead hole drilling, and forming preformed holes after lead hole drilling and reamed hole drilling; S8: square hole drilling: performing square hole drilling after preformed holes are formed by the lead hole drilling and reamed hole drilling of the drilling rig described above; S9: hole cleaning with round drill bit: after the step S8, cleaning sediment at the bottom of the hole, and repeatedly sweeping the bottom of the hole from one end to the other end until the sediment at the bottom of the hole is basically cleaned up; S10: hole cleaning with square drill bit: continuing to clean the sediment at the bottom of the hole with a square drill bit for hole cleaning. 
     Preferably, after the step S10, the method further comprises the following steps: 
     S11: measuring the sediment; S12: fabricating and installing a reinforcing cage; and S13: pouring concrete. 
     Preferably, the step S6 of lead hole drilling comprises the following two drilling methods according to different geological structures: 
     (1) four-corner lead hole drilling method: for pile foundation with stable stratum structure, opening plum-blossom-shaped lead holes at four corners of the pile foundation with a round pick bailing drill bit, each lead hole being drilled to the designed hole bottom elevation; 
     (2) single lead hole drilling method: for pile foundation with unstable stratum structure, drilling a lead hole in the pile foundation in the distal direction deviated from the drilling rig with a round pick bailing drill or drill bit until the designed hole bottom elevation, the size of the round pick bailing drill or drill bit being larger than that of the round pick bailing drill bit in the method (1). 
     Preferably, the step S7 of reamed hole drilling comprises following two hole-forming methods according to different geological structures: 
     (1) four-corner lead hole drilling method: for pile foundation with stable stratum structure, drilling in the center of a square pile with a round pick bailing drill until the designed pile bottom elevation and forming a preformed hole; 
     (2) single lead hole drilling method: for pile foundation with unstable stratum structure, drilling the square pile at the proximate end that is near the rotary drilling rig with a round pick bailing drill until the designed pile bottom elevation and forming a preformed hole, the size of the round pick bailing drill or drill bit being smaller than that of the round pick bailing drill bit in the method (1). 
     Preferably, the step S8 of square hole drilling is carried out by a square pile drill bit which comprises a box body, which is configured with a power driving device, a power transmission mechanism and an actuator; the power driving device comprises a power transmission shaft, a first connecting square head, a lifting pressure plate and a pressure conducting plate; the middle of the box body is configured with two power transmission shafts which are rotatably connected with the box body, and respectively located at upper and lower sides of the box body; the upper and lower sides of the shaft are respectively provided with a first bearing pressure plate and a second bearing pressure plate, which are connected with the box body by screws; the shaft is between the first bearing pressure plate and the second bearing pressure plate; the upper end of the box body is connected with a lifting pressure plate by screws; the upper outer wall of the power transmission shaft is provided with a shoulder which is in the lifting pressure plate; the lower side of the shoulder is configured with a pressure conducting plate which is fixedly connected to the upper side of the box body, and the upper side of the power transmission shaft is fixedly connected with the power input first connecting square head. 
     Preferably, the power driving device is connected with the power transmission mechanism; the power transmission mechanism comprises first driving sprockets, second driving sprockets, power input sprockets, first chains, reversing transmission boxes, transmission shafts, first sprockets, second sprockets and second chains; the middle of the power transmission shaft is connected with the first driving sprocket and the second driving sprocket; the first driving sprocket is located on the upper side of the second driving sprocket; both the left and right sides of the inner cavity of the box body are connected with the reversing transmission box; the upper end of the input shaft of the reversing transmission box is connected with the power input sprocket; the first chain is installed respectively between the power input sprocket on the left side and the first driving sprocket, and between the power input sprocket on the right side and the second driving sprocket; both the front and rear sides of the reversing transmission box are configured with an output shaft, and the output shaft of the reversing transmission box is connected with the transmission shaft via a shaft coupler. 
     Preferably, the power transmission mechanism is connected with an actuator, and the actuator comprises first actuating components and second actuating components; both the left and right sides at the lower part of the box body are configured with a first actuating component, which is in transmission connection with the transmission shaft through the first sprocket, the second sprocket and the second chain, and ends of the transmission shaft away from the box body are all configured with a second actuating component. 
     Preferably, the first actuating component comprises a rotary shaft and a first digging actuating element; the rotary shaft is rotatably connected with the box body; the outer wall of the rotary shaft is fixedly connected with the first digging actuating element; both the front and rear ends of the rotary shaft are configured with the second sprocket; the transmission shaft is connected with the first sprocket; the position of the first sprocket and the position of the second sprocket are in left-and-right correspondence, and the second chain is installed between the first sprocket and the second sprocket. 
     Preferably, the second actuating component comprises a crawler-type driving wheel, a crawler-type driven wheel, a crawler chain rail, a second digging actuating element, a power plate and a driven shaft; the crawler-type driving wheel is connected with one end of the transmission shaft away from the box body; both left and right sides at the lower part of the box body are rotatably connected with the driven shaft; both the front and rear ends of the driven shaft are connected with the crawler-type driven wheel; the position of the crawler-type driving wheel and the position of the crawler-type driven wheel are in left-and-right correspondence; the crawler chain rail is installed between the crawler-type driving wheel and the crawler-type driven wheel; the outer wall of the crawler chain rail is fixedly connected with the power plate, and both front and rear sides of the power plate are connected with the second digging actuating element. 
     Preferably, the lower side of the box body is connected with a lifting protection shaft, and the lifting protection shaft is located at the lower side of the first power transmission shaft. 
     Preferably, the step S8 of square hole drilling is carried out by a square pile drill bit, the square pile drill bit comprises a power head component, a power transmission component and third actuating components; the power head component comprises a frame, a second connecting square head, a second power transmission shaft and slewing bearings; both the upper and lower sides at the middle part of the frame are installed with the slewing bearing; the frame is rotatably connected with the second power transmission shaft through the slewing bearing; the upper end of the second power transmission shaft is fixedly connected with the second connecting square head, and the outer edge of the frame is uniformly installed with the third actuating components. 
     Preferably, the actuating component comprises transmission shafts, shaft sleeves and cutting actuating elements; the shaft sleeve is connected to the outer edge of the frame, and the inside of the shaft sleeve is rotatably connected with the transmission shaft through the bearing. 
     Preferably, the cutting actuating element comprises first cutting actuating elements and second cutting actuating elements, which are respectively fixedly connected to lower ends of two adjacent transmission shafts, and the first cutting actuating element and the second cutting actuating element are distributed in a staggered manner. 
     Preferably, the power transmission component is between the third actuating component and the power head component, comprising driving sprockets, first driven sprockets, second driven sprockets, first transmission chains and second transmission chains; the upper end of the second power transmission shaft is installed with two driving sprockets; the positions of the two driving sprockets are in up-and-down correspondence; the upper end of the transmission shaft on the left side is connected with the first driven sprocket; the upper end of the transmission shaft on the right side is connected with the second driven sprocket; the first transmission chain is between the driving sprocket on the upper side and the first driven sprocket, and the second transmission chain is ; between the driving sprocket on the lower side and the second driven sprocket. 
     Preferably, the second power transmission shaft is a stepped shaft, and the stepped part of the second power transmission shaft is at the lower side of the frame. 
     Preferably, the driving sprocket is matched with both the first driven sprocket and the second driven sprocket, and the first driven sprocket is the same as the second driven sprocket, and the outer diameter length of the driving sprocket is larger than the outer diameter lengths of the first driven sprocket and the second driven sprocket. 
     Preferably, the slewing bearing is a slewing bearing without external teeth. 
     Preferably, the step S8 of square hole drilling is carried out by a square pile drill bit, which comprises a box body; the edges inside the box body are longitudinally configured with evenly arranged grinding shaft sleeves; the lower ends of the evenly arranged grinding shaft sleeves all penetrate the lower sidewall of the box body and extend to the lower end of the box body, configured with grinding heads; the upper ends of the grinding shaft sleeves all penetrate the upper sidewall of the box body and extend to the upper end of the box body, configured with hydraulic motors; the sidewall of the hydraulic motor is configured with an oil outlet; the upper end of the oil outlet is provided with an oil inlet; oil tanks are fixedly arranged inside the box body; the number of the oil tanks is at least two, and a motor and a hydraulic pump are between the respective oil tanks. 
     Preferably, the motor comprises a first motor, the output end of the first motor is configured with a first hydraulic pump; the sidewall of the first hydraulic pump is configured with a first inlet and a first outlet; the right end of the first motor is configured with a second motor; the output end of the second motor is configured with a second hydraulic pump, and the sidewall of the second hydraulic pump is configured with a second inlet and a second outlet. 
     Preferably, the upper sidewall of the box body is configured with an anti-rotation plate; a third connecting square head is longitudinally arranged inside the anti-rotation plate; the lower sidewall of the third connecting square head is connected with the upper sidewall of the box body; the sidewall of the third connecting square head is configured with symmetrical square head reinforcing plates, and one side of the square head reinforcing plate away from the third connecting square head is connected with the inner wall of the anti-rotation plate. 
     Preferably, a grinding head transmission shaft is longitudinally arranged inside the grinding shaft sleeve; the lower end of the grinding head transmission shaft is connected with the grinding head; the upper end of the grinding head transmission shaft penetrates the upper sidewall of the grinding shaft sleeve and is connected with the output end of the hydraulic motor, and the upper end of the wall of the grinding head transmission shaft is rotatably connected with the grinding shaft sleeve. 
     Preferably, the grinding head comprises a cutter body and convex components, and the convex components are uniformly arranged around the cutter body. 
     Preferably, the oil outlet of the hydraulic motor is connected with the oil tank; the first inlet of the first hydraulic pump and the second inlet of the second hydraulic pump are both connected with the oil tank, and the first outlet of the first hydraulic pump and the second outlet of the second hydraulic pump are both connected with the hydraulic motor. 
     Preferably, the square drill bit for hole cleaning in step S10 is a square pile hole cleaning drill and comprises a power input fourth connecting square head and a mounting frame plate; the bottom of the power input fourth connecting square head is connected with a mounting plate; the bottom of the mounting plate is connected with an outer ring of a slewing bearing with external teeth; an inner ring of the slewing bearing with external teeth is connected to the middle of the top of the mounting frame plate; both left and right sides at the top inside the mounting frame plate are longitudinally configured with movable grooves, an inner wall of the movable groove is configured with a bearing; an inner wall of the bearing is connected with an outer wall of a connecting post; a top of the connecting post is connected with a transmission gear; an outer ring of the slewing bearing with external teeth is engaged with the transmission gear; a bottom of the connecting posts on left and right sides is respectively connected with a first winding drum and a second winding drum; the middle part inside the mounting frame plate is longitudinally configured with a sliding post, a top and bottom of a front face of the sliding post are respectively configured with a first connecting shaft and a fifth connecting shaft; the outer wall of the sliding post is sleeved with a stretching connecting sleeve; the upper part, middle part and lower part of the front face of the stretching connecting sleeve are respectively configured with a second connecting shaft, a third connecting shaft and a fourth connecting shaft; a first winding drum and a second winding drum are respectively wound thereon with one end of a first wire rope and a second wire rope; the other end of the first wire rope is converted and connected with a knot to the second connecting shaft through the first connecting shaft; the other end of the second wire rope is converted and connected with a knot to the fourth connecting shaft through the fifth connecting shaft; both the left and right sides at the top of the mounting frame plate are hinged with a soil clamping plate; the third connecting shaft is connected with one end of the transmission shaft through a pin shaft, and the other end of the transmission shaft is hinged with the soil clamping plate. 
     The present invention has the following benefits: the present invention provides a new square pile construction method of a rotary drilling rig, which can use equipment for square pile construction in the whole process, effectively reduce the underground operation of laborers, and avoid the project safety production risk from the source. The present invention also provides three kinds of square pile drill bits and a square pile hole cleaning drill in cooperation with the square pile construction method, which further realizes the mechanization of the whole process of square pile construction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic flowchart diagram of a square pile construction method of a rotary drilling rig of the present invention. 
         FIG. 2  is a schematic structural view of a square pile drill bit according to one embodiment of the present invention. 
         FIG. 3  is a schematic view of a sectional structure along line A-A of  FIG. 2 . 
         FIG. 4  is a schematic view of a sectional structure along line B-B of  FIG. 2 . 
         FIG. 5  is a schematic view of the structure of  FIG. 2  viewed at the right side. 
         FIG. 6  is a schematic structural view of a second actuating component of the square pile drill bit of  FIG. 2  according to one embodiment. 
         FIG. 7  is a schematic top view of the structure of  FIG. 2 . 
         FIG. 8  is a schematic perspective view of the structure of  FIG. 2 . 
         FIG. 9  is a schematic view of a first actuating component of the square pile drill bit of  FIG. 2  according to another embodiment. 
         FIG. 10  is a schematic view of a second actuating component of the square pile drill bit of  FIG. 2  according to another embodiment. 
         FIG. 11  is a schematic structural view of a square pile drill bit according to a second embodiment of the present invention. 
         FIG. 12  is a schematic bottom view of the structure of  FIG. 11 . 
         FIG. 13  is a schematic top view of the structure of  FIG. 11 . 
         FIG. 14  is a schematic structural view along line A-A of  FIG. 13 . 
         FIG. 15  is a schematic structural view along line B-B of  FIG. 14 . 
         FIG. 16  is a schematic perspective view of the structure of  FIG. 11 . 
         FIG. 17  is a schematic structural view of two actuating components of the square pile drill bit of  FIG. 11 . 
         FIG. 18  is a schematic perspective view of the structure of a first cutting actuating element. 
         FIG. 19  is a schematic perspective view of the structure of a second cutting actuating element. 
         FIG. 20  is a schematic top view of the structure of a square pile drill bit according to a third embodiment of the present invention. 
         FIG. 21  is a schematic front view of the structure of  FIG. 20 . 
         FIG. 22  is a schematic view of the sectional structure along line A-A of  FIG. 20 . 
         FIG. 23  is a schematic view of the sectional structure along line B-B of  FIG. 21 . 
         FIG. 24  is a schematic sectional view of the structure of a grinding shaft sleeve of the square pile drill bit of  FIG. 20 . 
         FIG. 25  is a schematic structural view of a grinding head of the square pile drill bit of  FIG. 20 . 
         FIG. 26  is a schematic structural view of a rotary drill for hole cleaning of a square pile according to one embodiment of the present invention (in a closed state). 
         FIG. 27  is a left view of  FIG. 26 . 
         FIG. 28  is a perspective view of  FIG. 26 . 
         FIG. 29  is a schematic view of the unfolding structure of a soil clamping plate for the hole cleaning drill of the square pile of  FIG. 26 . 
     
    
    
     DETAILED DESCRIPTION 
     The technical solution of the present invention will be clearly and completely described below with reference to drawings in the present invention. Obviously, the embodiments described are only a part but not all of the embodiments of the present invention. Unless particularly specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. 
     In the description of the present invention, it shall be appreciated that, orientations or positional relationships indicated by terms of “longitudinal”, “lateral”, “up”, “down”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside” and “outside” are orientations or positional relationships shown based on the drawings, and they are only used for convenience of describing the present invention, and are not intended to indicate or imply that the device or element indicated must have a specific orientation, be constructed and operated in a specific orientation. Thus, these terms cannot be understood as limitation of the present invention. 
     A first objective of the present invention is to provide a square pile construction method of a rotary drilling rig. The construction machineries, processes, drilling tools adopted or the like vary depending on different geological structures and different design specifications of square slide-resistant piles. All embodiments of the present invention take square piles with a design specification of (2.0 m×3.0 m) as examples. As shown in  FIG. 1 , the construction method specifically comprises the following steps: 
     S1: site leveling: performing land leveling and compaction on land at the construction site in advance; 
     S2:surveying and setting-out: measuring data and setting out on the leveled site, and marking out a position where drilling and construction are required; 
     S3: creating concrete retaining wall of wellhead: pouring concrete to form the retaining wall at the position where drilling and construction are required; 
     S4: putting the drilling rig in place: moving the drilling rig to the retaining wall, and before putting the drilling rig in place, the ground is compacted to ensure the stability of the drilling rig, thereby preventing inclination or displacement due to subsidence during drilling; 
     S5: adjusting the verticality of the drilling rig: in order to ensure the verticality of pile foundation after hole formation, adjusting the verticality of the drill pipe of the rig according to the level meter carried by the rig itself, so that the drill pipe of the rig corresponds to the center position of the retaining wall; 
     S6: lead hole drilling: setting lead holes in the retaining wall, and performing drilling based on the lead holes to form square pile drilled holes. 
     The step S6 of lead hole drilling specifically comprises the following two drilling methods according to different geological structures: 
     A. lead hole drilling method I, four-corner lead hole drilling method: for pile foundation less prone to hole collapse with stable stratum structure as revealed by the geological survey report, opening plum-blossom-shaped lead holes at four corners of the pile foundation with a φ 800 mm round pick bailing drill bit [taking the square pile with a design specification of (2.0 m×3.0 m) as an example], each lead hole being drilled to the designed hole bottom elevation; 
     B. lead hole drilling method II, single lead hole drilling method: for pile foundation prone to hole collapse with unstable stratum structure as revealed by the geological survey report, in order to prevent deviation of the pipe hole, drilling lead holes in the pile foundation in the distal direction deviated from the drilling rig with a φ 1500 mm round pick bailing drill or drill bit [taking the square pile with a design specification of (2.0 m×3.0 m) as an example] until the designed hole bottom elevation according to the topography and site conditions. 
     S7: Reamed hole drilling: continuing to drill reamed holes on the basis of lead hole drilling, and forming preformed holes after lead hole drilling and reamed hole drilling. 
     According to different geological structures, the reamed hole drilling specifically comprises the following two hole forming methods, which respectively correspond to the methods I and II of the step S6: 
     A. reamed hole drilling method I, four-corner lead hole drilling method: for pile foundation having plum-blossom-shaped lead holes and stable stratum structure, drilling in the center of the square pile by the rotary drilling rig with a φ 2000 mm round pick bailing drill until the designed pile bottom elevation and forming a preformed hole (corresponding to the method I of the step 6: four-corner lead hole drilling method); 
     B. reamed hole drilling method II, single lead hole drilling method: for pile foundation having a single lead hole which is prone to hole collapse with unstable stratum structure as revealed by the geological survey report, drilling the square pile at the proximate end that is near the rotary drilling rig with a φ1500 mm or φ1800 mm round pick bailing drill until the designed pile bottom elevation and forming a preformed hole (corresponding to the method II of the step 6: single lead hole drilling method). 
     Since the geological structure of pile foundation adopting the single lead hole drilling method is relatively unstable, if the hole collapse is serious during drilling, a slurry retaining wall or steel casing retaining wall for deep foundation square pile should be adopted reasonably and timely to follow up the construction. 
     S8: Square hole drilling: performing square hole drilling after preformed holes are formed by the lead hole drilling and reamed hole drilling of the drilling rig described above, and converting the lateral rotational kinetic energy into longitudinal rotational kinetic energy through the conversion of the kinetic energy transmission component mechanism by using the kinetic energy of the drilling rig, and then performing digging and trimming treatment by the actuating component mechanism of the square pile drill bit. In the process of square hole drilling, if pile casing is required because of serious hole collapse, each side should be enlarged by 100 mm according to the design specification, and the square steel casing should be made with the length corresponding to the hole collapse depth and lowered below the hole collapse elevation, so as to serve as a retaining wall and prevent hole collapse. Because a large amount of sediment falls from the hole wall to the bottom of the preformed hole during the square hole drilling process, and the square pile drill bit does not have the function of sediment fishing; sediment fishing using a round drill bit and square hole drilling should be repeatedly for several times during the square hole drilling process until the square hole is drilled to the designed hole bottom elevation. 
     S9: Hole cleaning with circular drill bit: after the step S8, cleaning sediment at the bottom of the hole; first cleaning the sediment at four corners with a φ 800 mm hole cleaning drill bit, then cleaning the whole bottom of the hole with a φ 2000 mm hole cleaning drill bit, and repeatedly sweeping the bottom of the hole from one end to the other end until the sediment at the bottom of the hole is basically cleaned up. 
     S10: Hole cleaning with square drill bit: continuing to clean the sediment at the bottom of the hole with a square drill bit for hole cleaning; the principle of hole cleaning with the square drill bit is to use a movable connecting rod combined with double loose-leaf sediment clamping plates to slowly pull the central movable connecting rod under the strong self-gravity of the hole cleaner, so that the double loose-leaf sediment clamping plates are automatically closed to scrape all the sediment at the bottom of the hole to the center at the bottom of the hole and form an inverted triangular sediment clamping space, and then, the square pile hole cleaner is pulled by the drill pipe of the rotary drilling rig. This step can be repeated for many times to clean the sediment at the bottom of the hole until the sediment at the bottom of the hole is completely removed. 
     S11: Measuring the sediment: after the hole cleaning by the square drill bit is finished, measuring the sediment at the bottom of the hole by using a sediment tray, and proceeding to the next process only after it is qualified; and if it is unqualified, the hole will be cleaned twice or for several times, or the round drill bit for hole cleaning may be used for repeated hole cleaning. 
     S12: Fabricating and installing a reinforcing cage: preparing and preliminarily manufacturing the reinforcing cage according to the design requirements in the special processing factory; and performing binding, welding and molding at the construction site. 
     In the step S12, the construction points of fabrication and installation of the reinforcing cage are as follows: the diameter and reinforcement specifications of the reinforcing cage meet the design requirements; thickness of the protective layer of the reinforcing cage is 50 mm; the section of the main reinforcement cannot be damaged when welding; the fabrication and storage areas should be kept flat, clean, covered with underlay at both upper and lower sides, and being rainproof and waterproof. 
     Hoisting and installation of the reinforcing cage: the reinforcing cage can be hoisted and placed only after passing the acceptance inspection, and the inspection contents comprise: the length and diameter of the cage should meet the requirements; whether the welding of the hoisting skeleton at the top of the reinforcing cage meets requirement of safety hoisting construction, and whether the length of the longitudinal reinforcement of the supporting pile anchored into the crown beam meets the design requirements, 
     the square pile reinforcing cage should be hoisted in parallel with the four-corner support hoisting skeleton, and it should be hoisted high and lowered slowly when it is hoisted and lowered, and meanwhile, special persons should be assigned to straighten the square pile reinforcing cage around the reinforcing cage, so as to avoid scratching of the hole wall of the square pile as much as possible, thereby preventing the debris from falling from the hole wall and forming the sediment at the bottom of the hole. 
     S13: Pouring concrete: adopting underwater concrete pouring method for concrete pouring, wherein two sets of conduits are used for construction at the same time due to the relatively large designed cross section of the square pile, and the process comprises: putting crane in place, measuring hole depth, calculating conduit length, laying conduits and pouring concrete. 
     The conduit length is determined according to the hole depth actually measured, and a discharging gap at the bottom of the hole is controlled at 200 mm˜400 mm from the lower end of the conduit to the bottom of the hole during construction. 
     Initial pouring requirements: the initial pouring amount is a key index of concrete pouring, and after initial pouring, the embedded depth of the conduit should be ensured to be not less than 2.0 m. 
     Concrete pouring: The strength of concrete adopts underwater concrete according to the design requirements, and the mixing ratio shall be provided by the mixing station and strictly implemented. After each concrete pouring, the rising height of the concrete surface should be measured in time; the buried depth of the conduit should be calculated; the conduit should be dismantled in time, and the buried depth of the conduit is preferably not greater than 8.0 m. The embedded depth of the conduit shall not be less than 3.0 m after each dismantling of the conduit. When it is confirmed that the concrete is poured to the top of the pile, the elevation of the concrete surface should be carefully detected, and the conduit can be lifted only after it is confirmed to be qualified. In the process of concrete pouring, manpower and material resources should be organized well to perform pouring continuously without intermediate pause, and underwater concrete pouring should be completed in the shortest time. The last pouring amount should be controlled and the pile top should not be low even slightly, and a laitance layer, which is in contact with concrete, on the upper layer of concrete needs to be chipped away. Therefore, the height of concrete needs to be over-poured by 500 mm, and the part above the designed elevation should be chipped away with manpower or manpower combined with an air pick, and the pouring process shall be well recorded by a pouring recorder. 
     In the process of concrete pouring, in case of a pile foundation embedded with square steel casing, an appropriate over-pouring coefficient should be calculated according to the volume of casing and conditions of the hole collapse outside the casing for appropriate over-pouring, and the steel casing is pulled out by cranes or other machines in real time after concrete pouring is completed. After 48 hours from the completion of concrete pouring, the part above the designed pile top elevation is chipped away with manpower or manpower combined with an air pick according to design requirements to complete the removal of pile head. Then pile maintenance and construction are completed after detection of pile foundation is performed only after the maintenance period is reached according to the requirements of relevant specifications. 
     A second objective of the present invention is to provide a new square pile drill bit (mainly used in the step S8 of the above-mentioned construction method) in cooperation with the above-mentioned construction method. 
     An embodiment of the square pile drill bit is a square pile drill bit for square drilling of poured pile foundation as shown in  FIG. 2  to  FIG. 10 . It shall be noted that: “poured” as used in “poured pile foundation” here does not specifically refer to a certain process, let alone S13 in the above-mentioned construction method, but represents the form of pile formation as “pile formation by pouring”. The square pile drill bit used here is mainly used in the step S8 of the above-mentioned construction method. The square pile drill bit comprises a box body  14 , and the box body  14  is installed with a power driving device, a power transmission mechanism and an actuator. The box body  14  is cuboid. The power driving device comprises a first power transmission shaft  18 , a power input first connecting square head  11 , a lifting pressure plate  15  and a pressure conducting plate  12 . The middle of the box body  14  is installed with the first power transmission shaft  18 , and the first power transmission shaft  18  is rotatably connected with the box body  14  through a bearing  17 . The number of the bearings  17  is two, and the two bearings  17  are respectively located in the round holes of the upper and lower wall plates of the box body  14 , and the upper and lower sides of the bearing  17  are respectively provided with a first bearing pressure plate  13  and a second bearing pressure plate  16 . The first bearing pressure plate  13 , the second bearing pressure plate  16  and the box body  14  are connected by screws. The bearing  17  is installed between the first bearing pressure plate  13  and the second bearing pressure plate  16 , and the bearing  17  is fixed by the first bearing pressure plate  13  and the second bearing pressure plate  16 . The upper end of the box body  14  is connected with the lifting pressure plate  15  by screws. The upper outer wall of the first power transmission shaft  18  is provided with a shoulder  130 , which is located in the lifting pressure plate  15 . The lower side of the shoulder  130  is provided with the pressure conducting plate  12 , and the pressure conducting plate  12  is fixedly connected to the upper side of the box body  14 . The shoulder  130  is integrally formed with the first power transmission shaft  18 , and thus the structure is stable. 
     As shown in  FIG. 3  and  FIG. 4 , the upper side of the first power transmission shaft  18  is fixedly connected with the power input first connecting square head  11 . During use, the square pile drill bit is connected to the existing rotary drilling rig through the first connecting square head  11 , and the rotary drilling rig drives the first connecting square head  11  to rotate for power input. 
     The power driving device is connected with a power transmission mechanism, and the power transmission mechanism comprises first driving sprockets  19 , second driving sprockets  110 , power input sprockets  127 , first chains  128 , reversing transmission boxes  123 , transmission shafts  122 , first sprockets  129 , second sprockets  121  and second chains  126 . The middle of the first power transmission shaft  18  is connected with the first driving sprocket  19  and the second driving sprocket  110  by screws. The first driving sprocket  19  is located on the upper side of the second driving sprocket  110 . Both the left and right sides of the inner cavity of the box body  14  are connected with the reversing transmission box  123  through bolts. The reversing transmission boxes  123  are T-shaped reversing transmission boxes, such as T-series spiral bevel gear diverter, which belong to a mature existing technology. The transmission mode of the reversing transmission box  123  is speed reduction transmission, which is a mature existing technology, and the match ratio (speed ratio) simply needs be adjusted according to the gear size. The controllable reduction of rotational speed can be realized by adopting the speed reduction transmission. The upper end of the input shaft of the reversing transmission box  123  is connected with the power input sprocket  127  through screws, the power input sprocket  127  on the left side is at the same height as the first driving sprocket  19 , and the power input sprocket  127  on the right side is at the same height as the second driving sprocket  110 . It shall be noted that in  FIG. 4 , the first driving sprocket  19  and the second driving sprocket  110  overlap, and only the first driving sprocket  19  is shown. The first chain  128  is respectively installed between the power input sprocket  127  on the left side and the first driving sprocket  19 , and between the power input sprocket  127  on the right side and the second driving sprocket  110 . Both the front and rear sides of the reversing transmission box  123  are provided with an output shaft, and the output shaft of the reversing transmission box  123  is connected with the transmission shaft  122  via a shaft coupler  124 . 
     The power transmission mechanism is connected with the actuator which comprises first actuating components  118  and second actuating components  112 . Both the left and right sides of the lower part of the box body  14  are installed with the first actuating component  118 . The first actuating component  118  is in transmission connection with the transmission shaft  122  through the first sprocket  129 , the second sprocket  121  and the second chain  126 . Ends of the transmission shafts  122  away from the box body  14  are all installed with the second actuating components  112 . 
     As shown in  FIG. 4  and  FIG. 5 , the first actuating component  118  comprises a rotating shaft  120  and a first digging actuating element  119 . The first digging actuating element  119  has a hard convex structure. The rotating shaft  120  is rotatably connected with the box body  14 , and the outer wall of the rotating shaft  120  is fixedly connected with the first digging actuating element  119 . Both the front and rear ends of the rotating shaft  120  are installed with the second sprocket  121 . The transmission shaft  122  is connected with the first sprocket  129  by screws, and the position of the first sprocket  129  and the position of the second sprocket  121  are in left-and-right correspondence. The second chain  126  is installed between the first sprocket  129  and the second sprocket  121 , and the transmission shaft  122  drives the rotating shaft  120  to rotate through the second chain  126 . The first digging actuating element  119  arranged by the first actuating component  118  is a hard protrusion, preferably a protrusion with the shape of a “bullet”. The first digging actuating elements  119  may be arranged evenly and parallel to the rotating shaft  120  as shown in  FIG. 4  and  FIG. 5 . Alternatively, the first digging actuating elements  119  may be distributed spirally on the surface of the rotating shaft  120  as shown in  FIG. 9 . The preferred solution is that the gap between respective first digging actuating elements  119  is 10 to 20 mm. 
     As shown in  FIG. 4  and  FIG. 6 , the second actuating component  112  comprises a crawler-type driving wheel  115 , a crawler-type driven wheel  113 , a crawler chain rail  114 , a second digging actuating element  117 , a power plate  116  and a driven shaft  125 . The crawler-type driving wheel  115  is connected with one end of the transmission shaft  122  away from the box body  14  by screws. Both the left and right sides of the lower part of the box body  14  are rotatably connected with the driven shaft  125 , and both the front and rear ends of the driven shaft  125  are connected with the crawler-type driven wheel  113  through bolts. The position of the crawler-type driving wheel  115  and the position of the crawler-type driven wheel  113  are in left-and-right correspondence, and the crawler chain rail  114  is installed between the crawler-type driving wheel  115  and the crawler-type driven wheel  113 . The outer wall of the crawler chain rail  114  is fixedly connected with the power plate  116 , and both the front and rear sides of the power plate  116  are welded with the second digging actuating element  117 . The transmission shaft  122  drives the crawler-type driving wheel  115  to rotate, so that the crawler chain rail  114  rotates, and the second digging actuating element  117  rotates together with the crawler chain rail  114 . Each of the second actuating components  112  may be provided thereon with a set of the second digging actuating elements  117  and power plate  116 , or provided thereon with a plurality of sets of the second digging actuating elements  117  and power plates  116  as shown in  FIG. 10 . The second digging actuating element  117  is preferably with the shape of a “bullet”. The preferred solution is that the orientation of the “bullet” of the second digging actuating element  117  is consistent with the rotation direction of the crawler-type driving wheel  115 . 
     As shown in  FIG. 3 , the lower side of the box body  14  is connected with a lifting protection shaft  111  by screws. The shifting protection shaft  111  is located at the lower side of the first power transmission shaft  18 . When the shifting pressure plate  15  breaks down, the shifting protection shaft  111  can protect the first power transmission shaft  18  from falling. 
     The working principle of this embodiment is as follows: when the square pile drill bit works downward, the downward pre-pressure is transmitted to the first power transmission shaft  18  through the power input first connecting square head  11 , and the first power transmission shaft  18  transmits the pre-pressure to the box body  14  through the pressure conducting plate  12 . When the square pile drill bit moves upward, the first power transmission shaft  18  cooperates with the lifting pressure plate  15  through the shoulder  130 , and then transmits the lifting force to the box body  14 . In case of power input, the first power transmission shaft  18  is in a rotating state, the box body  14  is stationary, and the power input first connecting square head  11  is driven by the power head of the rotary drilling rig to input the power source. The power transmission mechanism transmits the power on the power driving device to the actuator. The power head of the rotary drilling rig drives the first power transmission shaft  18  to rotate through the power input first connecting square head  11 , and the first power transmission shaft  18  drives the power input sprocket  127  to rotate through the transmission of the first chain  128 . The power input sprocket  127  drives the output shaft of the reversing transmission box  123  to rotate, then the output shaft of the reversing transmission box  123  drives the transmission shaft  122  to rotate, and the transmission shaft  122  drives the first actuating component  118  and the second actuating component  112  to operate. The transmission shaft  122  drives the rotary shaft  120  to rotate through the second chain  126 , and the first digging actuating element  119  rotates together with the rotary shaft  120 . Meanwhile, the transmission shaft  122  can drive the crawler-type driving wheel  115  to rotate, the crawler-type driving wheel  115  drives the crawler chain rail  114  to rotate, and the second digging actuating elements  117  rotates together with the crawler chain rail  114  for digging downward, and the square pile drill bit performs digging on the basis of the round hole to cut the wall of the hole flat. 
     Another embodiment of the square pile drill bit is as shown in  FIG. 11  to  FIG. 19 . A cutting square pile drill bit comprises a power head component  21 , a power transmission component  27  and third actuating components  211 . The power head component  21  comprises a frame  22 , a second connecting square head  24 , a second power transmission shaft  25  and slewing bearings  26 . Both the upper and lower sides of the middle part of the frame  22  are installed with the slewing bearing  26 , and the frame  22  is rotatably connected with the second power transmission shaft  25  via the slewing bearing  26 , and the upper end of the second power transmission shaft  25  is fixedly connected with the second connecting square head  24 . The rotary drilling rig inputs power through the second connecting square head  24  to drive the second power transmission shaft  25  to rotate. 
     The outer edge of the frame  22  is uniformly installed with the third actuating components  211 . As shown in  FIG. 17  to  FIG. 19 , the third actuating component  211  comprises transmission shafts  215 , shaft sleeves  216  and cutting actuating elements  212 . The shaft sleeve  216  is connected to the outer edge of the frame  22  by screws, and the inside of the shaft sleeve  216  is rotatably connected with the transmission shaft  215  by the bearing. The cutting actuating element  212  comprises first cutting actuating elements  217  and second cutting actuating elements  218 . The first cutting actuating element  217  and the second cutting actuating element  218  are fixedly connected to the lower ends of two adjacent transmission shafts  215  respectively, and the first cutting actuating element  217  and the second cutting actuating element  218  are distributed in a staggered manner. The cutting parts of the cutting actuating element  212  itself are distributed in a staggered manner in the up-and-down direction, as shown in  FIG. 17 , so as to realize cutting position abdication and cross cutting. According to one embodiment, a single first cutting actuating element  217  comprises a plurality of symmetrically arranged structures with the shape of dual parallel lines of equal length and a plurality of protrusions are arranged on the horizontal structures. Correspondingly, a single second cutting actuating element  218  comprises a plurality of symmetrically arranged structures with the shape of a line, and the number, shape and size of the structure with the shape of the line all correspond to those of the structure with the shape of dual parallel lines of equal length of the first cutting actuating element  217  so as to right snap into the middle of the two horizontal structures. Similarly, the horizontal structure of the structure with the shape of the line is also provided with several protrusions. When the first cutting actuating element  217  and the second cutting actuating element  218  are engaged with each other, the protrusions on their horizontal structures are disposed in a staggered manner. In one embodiment (the illustrated embodiment), the number of the structures with the shape of dual parallel lines of equal length on a single first cutting actuating element  217  and the number of the structures with the shape of the line on a single second cutting actuating element  218  are respectively set to be three. As shown in  FIG. 12 , a plurality of cutting actuating elements  212  are arranged in a rectangular shape as a whole, and the respective cutting actuating elements  212  is arranged along the inner wall of the box body in turn, without interfering with each other, and are used for cutting piles with square holes. 
     As shown in  FIG. 14  and  FIG. 15 , the power transmission component  27  is arranged between the third actuating component  211  and the power head component  21 . The power transmission component  27  comprises driving sprockets  23 , first driven sprockets  29 , second driven sprockets  210 , first transmission chains  213  and second transmission chains  214 . The upper end of the second power transmission shaft  25  is installed with two driving sprockets  23 , and the positions of the two driving sprockets  23  are in up-and-down correspondence. The upper end of the transmission shaft  215  on the left side is connected with the first driven sprocket  29  by screws, and the upper end of the transmission shaft  215  on the right side is connected with the second driven sprocket  210  by screws. The first driven sprocket  29  and the driving sprocket  23  on the upper side are in the same plane, and the second driven sprocket  210  and the driving sprocket  23  on the lower side are in the same plane. The first transmission chain  213  is installed between the driving sprocket  23  on the upper side and the first driven sprocket  29 , and the second transmission chain  214  is installed between the driving sprocket  23  on the lower side and the second driven sprocket  210 . The driving sprocket  23  drives the first driven sprocket  29  and the second driven sprocket  210  to rotate, and then the cutting actuating element  212  is driven to rotate for cutting (in order to prevent neatness from being compromised by too many lines, the first transmission chain  213  and the second transmission chain  214  are not schematically shown in  FIG. 14 ). 
     The driving sprocket  23  is matched with both the first driven sprocket  29  and the second driven sprocket  210 , and the lengths of the outer diameters of the first driven sprocket  29  and the second driven sprocket  210  are the same. The length of the outer diameter of the driving sprocket  23  is larger than those of the first driven sprocket  29  and the second driven sprocket  210 . That is, the large sprocket drives the small sprocket to rotate, so as to achieve the purpose of increasing the speed by transmission. 
     The second power transmission shaft  25  is a stepped shaft, and the stepped part of the second power transmission shaft  25  is located at the lower side of the frame  22 , so as to realize the power input and rotation of the second power transmission shaft  25 , while the frame  22  is in a stationary state. Meanwhile, the stepped part of the second power transmission shaft  25  may support and protect the frame  22  when the slewing bearing  26  breaks down. The slewing bearing  26  is a slewing bearing without external teeth. The upper side of the frame  22  is connected with a protective cover  28  by screws. 
     The working principle of this embodiment is as follows: the rotary drilling rig inputs power through the second connecting square head  24  to drive the second power transmission shaft  25  to rotate, and the second power transmission shaft  25  simultaneously drives the upper and lower driving sprockets  23  to rotate. Because the driving sprocket  23  on the upper side is in transmission connection with the first driven sprocket  29  through the first transmission chain  213 , and the driving sprocket  23  on the lower side is in transmission connection with the second driven sprocket  210  through the second transmission chain  214 , the transmission shaft  215  is driven to rotate, and then the cutting actuating element  212  is driven to rotate for cutting, so that piles with square hole are drilled on the basis of the piles with round holes. 
     A third embodiment of the square pile drill bit is as shown in  FIG. 20  to  FIG. 25 . A hydraulic grinding square pile drill bit comprises a box body  31 , and the edges inside the box body  31  are longitudinally provided with evenly arranged grinding shaft sleeves  32 . The lower ends of the evenly arranged grinding shaft sleeves  32  all penetrate the lower sidewall of the box body  31  and extend to the lower outer end of the box body  31 , and are fixedly provided with grinding heads  33 . The upper ends of the grinding shaft sleeves  32  all penetrate the upper sidewall of the box body  31  and extend to the upper outer end of the box body  31 , and are fixedly provided with hydraulic motors  34 . The sidewall of the hydraulic motor  34  is fixedly provided with an oil outlet, and the upper end of the oil outlet is fixedly provided with an oil inlet. Symmetrical oil tanks  35  are fixedly arranged inside the box body  31 , and the oil outlet and the oil inlet are connected with the corresponding oil tanks  35  through pipelines respectively, so as to realize oil input and output; and specific oil input and output directions are as shown by the arrow direction in  FIG. 22 . A plurality of oil tanks  35  may be provided according to actual needs, and the figure shows a case where two oil tanks are provided. A first motor  36  is fixedly arranged between the two oil tanks  35 , and the output end of the first motor  36  is fixedly provided with a first hydraulic pump  37 . The sidewall of the first hydraulic pump  37  is fixedly provided with a first inlet and a first outlet, the right end of the first motor  36  is fixedly provided with a second motor  38 , the output end of the second motor  38  is fixedly provided with a second hydraulic pump  39 , and the sidewall of the second hydraulic pump  39  is fixedly provided with a second inlet and a second outlet. The oil outlet of the hydraulic motor  34  is fixedly connected with the oil tank  35 , the first inlet of the first hydraulic pump  37  and the second inlet of the second hydraulic pump  39  are all fixedly connected with the oil tank  35 , and the first outlet of the first hydraulic pump  37  and the second outlet of the second hydraulic pump  39  are all fixedly connected with the hydraulic motor  34 . 
     The upper sidewall of the box body  31  is fixedly provided with an anti-rotation plate  310 , and the inside of the anti-rotation plate  310  is longitudinally provided with a third connecting square head  311 . The lower sidewall of the third connecting square head  311  is fixedly connected with the upper sidewall of the box body  31 , the sidewall of the third connecting square head  311  is fixedly provided with symmetrical square head reinforcing plates  312 , and one side of the square head reinforcing plate  312  away from the third connecting square head  311  is fixedly connected with the inner wall of the anti-rotation plate  310 . 
     As shown in  FIG. 24 , a grinding head transmission shaft  313  is longitudinally arranged inside the grinding shaft sleeve  32 , and a bearing spacer  318  is arranged between the grinding head transmission shaft  313  and the grinding shaft sleeve  32 . The lower end of the grinding head transmission shaft  313  is fixedly connected with the grinding head  33  through a bearing  319 . 
     The upper end of the grinding head transmission shaft  313  penetrates the upper sidewall of the grinding shaft sleeve  32  and is fixedly connected with the output end of the hydraulic motor  34 . The upper end of the wall of the grinding head transmission shaft  313  is rotatably connected with the grinding shaft sleeve  32  through a lock nut  314 . The lower end of the hydraulic motor  34  is fixedly provided with a clamp  315 . The clamp  315  is a connecting component between the hydraulic motor  34  and the grinding head transmission shaft  313 , and it is specifically a structure composed of a key and a clamp. The grinding head transmission shaft  313  is provided thereon with holes and keys, and the output shaft of the hydraulic motor  34  is correspondingly provided thereon with shafts and keys. The clamp  315  connects the two parts by locking and clamping them together, which is a mature existing technology, and the connection between the hydraulic motor  34  and the grinding head transmission shaft  313  may also be realized by other existing technologies. As shown in  FIG. 25 , the grinding head  33  comprises a cutter body  316  and convex components  317  made of a hard alloy material, and the convex components  317  are uniformly arranged around the cutter body  316 . The square convex part at the top of the figure is a square positioning spigot provided on the part of the cutter body  316  of the grinding head  33 . 
     The working principle of this embodiment is as follows: the third connecting square head  311  of the rotary drilling rig is directly and rigidly connected (with rigid connection) above the box body  31  of the square pile drill bit, and the square head reinforcing plate  312  is arranged between the third connecting square head  311  and the box body  31  to strengthen the connection strength thereof. In this embodiment, the power of the grinding head  33  of the square pile drill bit is driven by the hydraulic system, and the power of the hydraulic system is driven by an independent motor. When the first motor  36  and the second motor  38  are powered on to rotate, they drive the first hydraulic pump  37  and the second hydraulic pump  39  to operate. The first hydraulic pump  37  and the second hydraulic pump  39  suck hydraulic oil from the oil tank  35  through the first inlet and the second inlet respectively, and the hydraulic oil is transmitted to each hydraulic motor  34  through respective oil outlets and the oil inlets via the hydraulic system respectively through the first outlet and the second outlet, thereby driving the hydraulic motor  34  to rotate. The hydraulic motor  34  is installed on the box body  31  of the square pile drill bit, and the output shaft of the hydraulic motor  34  is connected with the transmission shaft  313  of the grinding head  33 , thereby realizing the rotation of the grinding head  33 . The shafts of the grinding heads  33  are regularly distributed along the four walls of the box body  31  of the square pile drill bit, and the hydraulic systems are connected in series or in parallel according to the actual working conditions, so as to realize the rotation of all the grinding heads  33  on the four walls of the box body  31  of the square pile drill bit. 
     A third objective of the present invention is to provide a new square drill bit for hole cleaning (mainly used in the step S10 of the above-mentioned construction method) in cooperation with the above-mentioned construction method. Specifically, as shown in  FIG. 26  to  FIG. 29 , a rotary drilling bit for hole cleaning of square pile comprises a fourth connecting square head  41  for power input and a mounting frame plate  44 . The bottom of the fourth connecting square head  41  is welded with a mounting plate, and the bottom of the mounting plate is connected with the outer ring of the slewing bearing  42  with external teeth. The inner ring of the slewing bearing  42  with external teeth is connected in the middle of the top of the mounting frame plate  44  by screws. The slewing bearing  42  is similar to a bearing structure, and the inner and outer rings thereof are respectively mounted with spigots and screw holes, and the inner and outer rings can rotate independently. The slewing bearing  42  with external teeth refers to a tooth-shaped structure with involute in its outer ring part. Here, the connection with the outer ring of the slewing bearing  42  specifically means that the mounting plate is connected with the outer ring part of the slewing bearing  42  through the positioning spigots and screws. When the fourth connecting square head  41  for power input rotates, it can drive the outer ring part of the slewing bearing  42  to rotate to transmit power, while the inner ring part of the slewing bearing  42  is connected with the mounting frame plate  44  to keep the mounting frame plate  44  stationary. Both the left and right sides of the inner top of the mounting frame plate  44  are longitudinally provided with movable grooves, and the inner wall of the movable grooves is provided with bearings, and the inner wall of the bearings is connected with the outer wall of connecting posts. The top of the connecting post extends to the outside of the mounting frame plate  44  and is connected with a transmission gear  43 . The outer rings of the slewing bearing  42  with external teeth are respectively engaged with respective transmission gears  43 . The bottom of the connecting posts on left and right sides are respectively connected with a first winding drum  45  and a second winding drum  46 . The power is input through the fourth connecting square head  41 , and it drives the slewing bearing  42  with external teeth to rotate, and the rotation is transmitted to the first winding drum  45  and the second winding drum  46  respectively through the transmission gear  43 , which drives the first winding drum  45  and the second winding drum  46  to rotate. 
     The middle part inside the mounting frame plate  44  is longitudinally provided with a sliding post, the top and bottom of the front face of the sliding post are respectively provided with a first connecting shaft  47  and a fifth connecting shaft  412 . The outer wall of the sliding post is sleeved with a stretching connecting sleeve  410 , the upper part, middle part and lower part of the front face of the stretching connecting sleeve  410  are respectively provided with a second connecting shaft  49 , a third connecting shaft  414  and a fourth connecting shaft  413 . The first winding drum  45  and the second winding drum  46  are respectively wound thereon with a first wire rope  48  and a second wire rope  411 . The other end of the first wire rope  48  is converted and connected with a knot to the second connecting shaft  49  through the first connecting shaft  47 ; and the other end of the second wire rope  411  is converted and connected with a knot to the fourth connecting shaft  413  through the fifth connecting shaft  412 . If one of the first wire rope  48  and the second wire rope  411  on the first winding drum  45  and the second winding drum  46  is collected on the winding drum, then the other one thereof will be released from the winding drum. The outer diameters and rotational angular velocities of the first winding drum  45  and the second winding drum  46  are completely consistent, so that the lengths of wires winded and released are equal. Both the left and right sides at the top of the mounting frame plate  44  are hinged with a soil clamping plate  416 , the third connecting shaft  414  is connected with transport shafts  415  through a pin shaft, and the other end of the transport shaft  415  is hinged with the soil clamping plate  416 . The transport shafts  415  are symmetrically arranged, and the number of the transport shafts  415  is equal to that of the soil clamping plates  416 . When the first winding drum  45  rotates and the first wire rope  48  moves upward and shortens, the stretching connecting sleeve  410  is driven to move upward, and the angle included between respective transport shafts  415  is reduced (only one transport shaft  415  is schematically shown in  FIG. 26  due to simplicity of the views), and the soil clamping plate  416  is driven to be folded in the middle for soil clamping operation. Meanwhile, the second wire rope  411  on the second winding drum  46  is released with the same length. As shown in  FIG. 27 , the power input fourth connecting square head  41  drives the second winding drum  46  to rotate in the opposite direction (the rotation direction is opposite to the rotation direction indicated by the arrow in  FIG. 26 , that is, opposite to the rotation direction during soil clamping. It shall be noted that the direction shown in the figure is only for illustration, and in practice, it can be opened by being rotated clockwise or counterclockwise according to the actual situation and the winding direction of the wires), and the second wire rope  411  thereon moves downward and shortens, and the soil clamping plate  416  tends to open downward under the action of self-gravity, and the stretching connecting sleeve  410  moves downward, so that the angle included between the two transport shafts  415  becomes larger, thus realizing the opening of the soil clamping plate  416 . At the same time, the rotation of the first winding drum  45  allows the first wire rope  48  to be released with the same length. 
     The outer wall of the soil clamping plate  416  is provided with a wear-resistant and corrosion-resistant layer, which is a wear-resistant and corrosion-resistant coating, thus prolonging the service life and improving the wear-resistant and corrosion-resistant performance. The out wall of the slewing bearing  42  with external teeth and the outer wall of the transmission gear  43  are both provided with a lubricating layer, and the lubricating layer includes lubricating oil, thereby improving the transmission performance. 
     The working principle of this embodiment is as follows: the power is input through the fourth connecting square head  41 , and it drives the slewing bearing  42  with external teeth to rotate, and the rotation is transmitted to the first winding drum  45  and the second winding drum  46  respectively through the transmission gear  43 , which further drives the first winding drum  45  and the second winding drum  46  to rotate. The first wire rope  48  wound on the first winding drum  45  and the second wire rope  411  wound on the second winding drum  46  are wound in the forward and reverse directions respectively. The first winding drum  45  and the second winding drum  46  rotate in the same direction, and if one of the first wire rope  48  and the second wire rope  411  on the first winding drum  45  and the second winding drum  46  is collected on the winding drum, then the other one thereof will be released from the winding drum. The outer diameters and rotational angular velocities of the first winding drum  45  and the second winding drum  46  are completely consistent, so that the lengths of wires winded and released are equal. The soil clamping plates  416  are connected to the mounting frame plate  44  by a pin shaft, and the soil clamping plates  416  can rotate around their respective rotation centers. In this way, when the power input fourth connecting square head  41  rotates in the forward direction, the first winding drum  45  rotates and the first wire rope  48  moves upward and shortens, which drives the stretching connecting sleeve  410  to move upward, and the angle included between the two transport shafts  415  decreases, which drives the soil clamping plate  416  to be folded in the middle for soil clamping operation. At the same time, the second wire rope  411  on the second winding drum  46  is released with the same length. When the power input fourth connecting square head  41  rotates in the reverse direction, the second winding drum  46  rotates in the reverse direction, and the second wire rope  411  thereon moves downward and shortens, the soil clamping plate  416  tends to open downward under the action of self-gravity, and the stretching connecting sleeve  410  moves downward, so that the angle included between the two transport shafts  415  becomes larger, thus realizing the opening of the soil clamping plate  416 . At the same time, the rotation of the first winding drum  45  allows the first wire rope  48  to be released with the same length. 
     The embodiments described above only describe the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, all kinds of transformations, variations, modifications and substitutions made by those of ordinary skill in the art to the technical solution of the present invention should fall within the protection scope determined by the claims of the present invention.