Pile foundation construction method

Abstract

Disclosed in the present invention is a pile foundation construction method, comprising the following steps: S1, on the basis of the designed positions of pile foundations on a slope, and along two sides of pile positions within a straight line range from the top to the bottom of the slope, marking positions at which steel sheet piles need to be installed; S2, fixing a winch device at the top of the slope, installing a first movable platform and connecting same to the winch device to complete a full-section steel trestle; S3, placing a drilling device on the first movable platform, and using the winch device to enable the first movable platform to travel on the steel trestle to a planned position, fixing the first movable platform on the steel trestle, and then using the drilling device to perform pile hole construction at the pile positions; S4, repeating S3 until all pile holes in an area covered by the steel trestle are drilled, and subsequently detaching the drilling device from the first movable platform; S5, a hoisting device moving or traveling onto the first movable platform, and hoisting pile reinforcement cages into all the pile holes; and S6, pouring concrete into the pile holes. The present invention has the beneficial effect of facilitating pile foundation construction on mountainous slopes.

Description

Pile foundation construction method Technical Field

[0001] The present invention relates to the field of pile foundation construction of structures, and more particularly to a pile foundation construction method. Background Art

[0002] With the continuous development of the social economy and the continuous improvement of urbanization levels, roads and bridges are constantly being built or replaced, and new energy sources are being continuously promoted in society. As a result, a large number of non-temporary structures need to be constructed on mountainous areas, tidal flats, and permanent slopes, such as wind turbines, photovoltaic equipment platforms, bridge piers, and unconventional residential structures. These structures have high requirements for their own pile foundations and can no longer use temporary pile types such as steel sheet piles. In addition, since these pile foundations are often located in complex mountainous environments or permanent slopes, the construction process of such structures is much more difficult than construction on flat ground. In particular, during pile foundation construction, the conventional method is to first plan several sites and multiple construction roads according to the pile foundation design drawings. This will significantly increase the construction period and cost. In addition, large-scale blasting and other operations are required according to various conditions on hard mountains. In areas such as tidal flats, a large amount of ground hardening treatment is required. In mountainous areas with dense structures, it is even necessary to demolish surrounding buildings to ensure smooth construction roads. If there are planning requirements, the soil must be backfilled to its pre-construction state after construction is completed.

[0003] Faced with numerous site constraints and cost requirements, construction sites often rely on large numbers of personnel to manually dig holes on slopes or in areas inaccessible to construction machinery. After the holes are dug, simple lifting tools are used to lower the steel cage, followed by the concrete pouring of the pile body. This method suffers from low construction efficiency, high labor requirements, and a long construction period. To address these issues to a certain extent, when faced with complex site constraints such as river slopes and tidal mudflats, on-site engineers often use construction platforms to assist in pile foundation construction. However, the platform must be erected continuously as the pile foundation construction progresses. To save labor and shorten the construction period, for example, patent application CN109695237A, entitled "A Mobile Pile Foundation Construction Platform," utilizes auxiliary piles to enable the bearing platform to be movably connected to the top of the auxiliary piles along the direction of pile foundation construction. However, this type of platform can only be deployed horizontally and is not suitable for mountainous slopes. The platform itself is costly to erect and places high demands on equipment such as drilling rigs used on it. Therefore, it is necessary to design a pile foundation construction method based on a movable pile foundation construction platform suitable for mountainous slopes.

[0004] Summary of the Invention

[0005] An object of the present invention is to provide a pile foundation construction method that meets the characteristics of rapid mechanized construction of bored piles in complex terrain represented by mountain slopes.

[0006] In order to achieve these purposes and other advantages according to the present invention, according to one aspect of the present invention, the present invention provides a pile foundation construction method, comprising the following construction steps:

[0007] S1. Based on the designed location of the pile foundation on the slope, survey and mark the locations where the steel sheet piles are to be installed on both sides of the pile position within a straight line from the top of the slope to the bottom of the slope;

[0008] S2. Fix the hoisting device at the top of the slope, install the first movable platform and connect it to the hoisting device with a steel cable to complete the entire steel trestle;

[0009] S3, moving or driving the drilling equipment onto the first movable platform, using the hoisting equipment to drive the first movable platform to the designed position on the steel trestle, fixing the first movable platform to the steel trestle, and then using the drilling equipment to perform pile hole construction at the pile position;

[0010] S4, repeating S3 until all pile holes in the area covered by the steel trestle are drilled, and then unloading the drilling equipment from the first movable platform;

[0011] S5. Move or drive the hoisting equipment to the first movable platform, and hoist the pile reinforcement cage into all pile holes;

[0012] S6. Pour concrete into the pile hole to complete the construction of the pile foundation.

[0013] Preferably, the steel trestle includes two parallel and symmetrically arranged rail frames, and a single rail frame includes a plurality of spaced steel sheet piles, the pile bodies of the steel sheet piles are in the slope, and the tops of all the steel sheet piles are connected to the steel track, and all sections of the steel track from the highest point to the lowest point are downhill sections or horizontal sections.

[0014] Preferably, the first movable platform includes a steel frame platform, which is assembled from multiple groups of Bailey beams, a steel plate layer is detachably connected to the Bailey beam, and a platform bracket is detachably connected underneath the steel frame platform. The platform bracket is located above the steel trestle, and includes two horizontal bracket main beams parallel to the rail frame, a plurality of bracket secondary beams are detachably connected between the upper surface of the bracket main beam and the steel frame platform, and a traction bracket is detachably connected to the bottom surfaces of the plurality of bracket secondary beams. The platform bracket is connected to a traction bracket, which is connected to the winch equipment by a steel cable, and the platform bracket is connected to a hydraulic wheel set, which is in contact with the steel track below.

[0015] Preferably, it is characterized in that the steel track includes a plurality of steel corbels arranged at intervals, a steel track beam is connected between any two steel corbels, the steel corbels correspond to the top ends of the steel sheet piles one by one and are detachably connected, the top surfaces of the steel corbels are flat and flush with the top surfaces of the steel track beams on both sides at the joints without any height difference, and the vertical surface of the steel corbel close to the other side of the steel track is flush with the vertical surface of the steel track beam close to the other side of the steel track.

[0016] Preferably, the support main beams are located directly above the steel rails on each side, and the bottom surface of the support main beam is detachably connected to multiple support bases, which correspond one-to-one to the steel corbels below. There is a hydraulic jack between the bottom surface of the support base and the top surface of the steel corbel, and its height is equal to the net distance between the bottom surface of the support base and the top surface of the steel corbel.

[0017] Preferably, the first movable platform is installed and connected to the hoisting device with a steel cable to complete the full section of the steel trestle, including the following steps:

[0018] A1. Use a steel sheet pile driver to construct steel sheet piles at the top of the slope within the reach of its cantilever. Then install steel brackets on the top of each completed steel sheet pile, and connect the steel track beams and rail coupling beams between the steel brackets.

[0019] A2. Using the upper surface of the steel bracket as the base, place the hydraulic jacks on each steel bracket so that the top surfaces of the hydraulic jacks are at the same level. Install the platform support, traction support, steel frame platform, and hydraulic wheel assembly in sequence. Then, connect the traction support and winch equipment with a steel cable and move the required steel sheet pile driver to the steel frame platform.

[0020] A3. The winch straightens the steel cable and applies force. At this time, keep the hydraulic wheel assembly raised and adjust itself in time to keep the support platform level. After removing the hydraulic jacks, use the winch to lower the steel cable, allowing the first movable platform to slide down to the appropriate position under its own weight. While maintaining the tension of the winch, stop lowering the steel cable to stop the movable platform from sliding down. Install the hydraulic jacks between the support base and the steel bracket. After installation, retract the hydraulic wheel assembly so that the platform support rests on the jacks.

[0021] A4. Repeat A1 and A3 to extend to the bottom of the slope and complete the construction of the steel trestle.

[0022] Preferably, hoisting the pile reinforcement cage into all pile holes comprises the following steps:

[0023] B1. Lower the first movable platform carrying the lifting equipment to a suitable location, install the hydraulic jack, retract the hydraulic wheel assembly, and release the steel cable connection between the movable platform and the hoisting equipment;

[0024] B2. Install the second movable platform, place the pile reinforcement cage placement frame on it, and connect the hoist equipment to the second movable platform steel cable;

[0025] B3. Arrange a batch of pile reinforcement cages on the pile reinforcement cage placement rack at the top of the slope;

[0026] B4. Use the hoisting equipment to lower the second movable platform to the lifting area covered by the lifting equipment on the first movable platform;

[0027] B5. The lifting equipment lifts all the pile reinforcement cages on the second movable platform in sequence and places them into the pile holes within the lifting area. After completion, the second movable platform is raised to the top of the slope. Steps B3-B4 are repeated until all reinforcement cages within the lifting area are completed.

[0028] B6. Repeat B1-B3 until all pile reinforcement cages are constructed.

[0029] Preferably, the hydraulic wheel group includes two groups of symmetrical single-sided support wheel groups, which are connected to the lower surface of the bracket main beam, and the single-sided support wheel group includes multiple electric hydraulic cylinders, which are arranged at intervals and vertically fixed to the bottom surface of the bracket main beam. The hydraulic telescopic rod end bearing of each electric hydraulic cylinder is hinged with a distribution wheel frame, and the distribution wheel frame is in the shape of an upward convex crank. The surface bearing of the distribution wheel frame facing the proximal steel track is connected to two rollers, and the rollers are in contact with the top surface of the steel track.

[0030] The present invention has at least the following beneficial effects:

[0031] The steel trestle used in the present invention, in conjunction with the first movable platform and the second movable platform, can enable various types of construction machinery to carry out normal construction on mountainous areas or slopes, saving construction space, solving the restrictions of terrain on bored pile construction, and greatly saving the construction period and construction cost of bored pile projects in mountainous slope areas.

[0032] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic diagram of pouring pile foundation concrete in a pile foundation construction method in a technical solution of the present invention;

[0034] FIG2 is a schematic diagram of a steel trestle construction method of a pile foundation construction method in a technical solution of the present invention;

[0035] FIG3 is a schematic diagram of a drilling construction method of a pile foundation construction method in a technical solution of the present invention;

[0036] FIG4 is a schematic diagram of a pile reinforcement cage hoisting method of a pile foundation construction method in a technical solution of the present invention

[0037] FIG5 is a schematic diagram of a first movable platform of a pile foundation construction method in a technical solution of the present invention;

[0038] FIG6 is an exploded view of a first movable platform of a pile foundation construction method in a technical solution of the present invention;

[0039] FIG7 is a schematic diagram of a platform support and a hydraulic wheel assembly in a pile foundation construction method in a technical solution of the present invention;

[0040] FIG8 is a schematic diagram of a rail bent frame and contact components thereon in a pile foundation construction method in a technical solution of the present invention; DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can implement the invention with reference to the description.

[0042] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0043] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The orientations or positional relationships indicated by the terms "transverse", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0044] As shown in Figures 1 to 8, the present invention provides a pile foundation construction method, comprising the following steps:

[0045] S1. Based on the designed position of the pile foundation on the slope 6, survey and mark the positions where the steel sheet piles 201 are to be installed on both sides of the pile position within a straight line from the top of the slope 6 to the bottom of the slope 6. Specifically:

[0046] Before surveying the position of the steel sheet pile 201, it is first necessary to use special equipment such as a theodolite or total station to accurately locate the position of the cast-in-place pile. When surveying the position of the steel sheet pile, in addition to recording the slope of each section along the slope 6, it is also necessary to combine the previous pile base survey report to determine the amount of steel sheet pile 201 material to be prepared and select appropriate construction machinery and tools. At this time, the subsequent construction plan should be planned according to the site conditions.

[0047] S2. Fix the hoisting device 3 on the top of the slope 6, install the first movable platform 1 and connect it to the hoisting device 3 with the steel cable 31 to complete the entire steel trestle 2. Specifically:

[0048] The materials used to make the first movable platform 1 are all commercially available and have been processed in the processing plant. They only need to be assembled on site. The first movable platform 1 can be fixed on the steel trestle 2 and can use its own weight to slide down to the bottom of the slope 6 on the steel trestle 2 or be pulled to the top of the slope 6 by the winch equipment 3. There is a hydraulic device in the first movable platform 1 to ensure that the platform surface is always in a horizontal state. The winch equipment 3 uses a double set of 32-ton winches and uses multiple 10-ton winches to assist in sliding according to the size of the first movable platform 1. The winch equipment steel cable 31 has a diameter of 48 mm or above, and a forced rope reel is used to arrange the steel cables 31 neatly. All steel cable 31 plugs are plugged with cable buckles, and the steel cables 31 are connected to the first movable platform 1 with anti-detachment hooks.

[0049] S3, move or drive the drilling equipment 42 onto the first movable platform 1, use the hoisting device 3 to make the first movable platform 1 drive to the designed position on the steel trestle 2, fix the first movable platform 1 to the steel trestle 2, and then use the drilling equipment 42 to construct the pile hole 51 at the pile position. Specifically:

[0050] First, the first movable platform 1 is pulled down by the hoist 3, allowing it to slide down along the steel trestle 2 under the action of gravity. The first movable platform 1 is then fixed to the steel trestle 2 at a predetermined position. Subsequently, a steel casing is buried in the pile hole within the coverage area of ​​the drilling equipment 42. During the drilling process, the mud materials used for the mud wall are clay, water, and additives, which are prepared according to a specific ratio. The mud pool is planned in advance and established at or near the top of the slope 6. It is connected to the drilling equipment 42 via a pipeline and a mud pump. While the drilling equipment 42 is drilling the pile position, the drill bit advances slowly and at a uniform speed. The mud pump is started to circulate the drilling synchronously. The drilling depth must be strictly controlled during the drilling process. When drilling to the bottom of the casing, a low-speed and slow drilling strategy is required. After the drill bit or the guide part has completely entered the formation, a fast drilling strategy is switched to.

[0051] S4, repeat S3 until all pile holes 5 in the area covered by the steel trestle 2 are drilled, and then remove the drilling equipment 5 from the first movable platform 1. Specifically:

[0052] After the pile hole 5 is drilled, the mud sampling test is carried out. If it exceeds the standard, it should be handled in time. Professional record personnel are deployed to ensure that the data of the drilling are true and reliable. The drilling equipment 5 can be removed only after the pile hole 5 of the same batch is accepted.

[0053] S5. Move or drive the hoisting equipment 43 onto the first movable platform 1 and hoist the pile reinforcement cage 51 into all pile holes 5. Specifically:

[0054] When lowering the pile reinforcement cage 51, the cage should be kept vertical and aligned with the pile hole 5. The cage should be lowered slowly and gently to avoid collision with the hole wall. If resistance is encountered during the lowering of the cage, it should not be lowered forcibly. The cause should be identified before continuing the lowering of the cage. After the lowering is completed, the positioning bars should be fixed to the steel casing to ensure that there is no deviation during the pile pouring.

[0055] S6. Pour concrete into the pile hole to complete the construction of the pile foundation. Specifically:

[0056] A ground pump 440 is installed at the top of slope 6, and a concrete distributor 44 is mounted on the first movable platform 1. The first movable platform 1 is lowered to the planned location using a winch 3. A pump pipe 441 is then installed on slope 6, connecting the ground pump 440 and the concrete distributor 44. Concrete is poured from the ground pump 440 through the concrete distributor 44, extending through the pump pipe 441 and into the pile holes 5 within its coverage area. Commercially available commercial concrete, primarily sand and gravel, is used. To ensure the quality of bored pile construction, the concrete's gradation, workability, and slump must be controlled. Screening and cleaning are necessary. During this project, a 28cm diameter rigid grouting pipe is used for concrete pouring, with the lower end buried in the concrete to a depth of >2m. The pouring speed must be controlled to minimize the impact on the pile reinforcement cage 51. The steel trestle 2 is removed after all bored piles are completed.

[0057] In the present technical solution, the first movable platform 1 is movable while its own surface always keeps itself in a horizontal state. When the first movable platform 1 descends along the steel trestle 2, it relies on its own weight and the load on it, and is pulled by the winch equipment 3 to maintain balance and uniform speed. After the first movable platform 1 is lifted to the top of the slope 6 by the winch equipment 3, the mechanical equipment on it can be replaced to complete different processes in the bored pile construction process. During the construction process, the mechanical equipment does not need to be in direct contact with the slope 6, and there is no need to re-erect the surface when changing the working area. In addition to solving the difficult and tedious problem of bored pile construction in complex terrains such as mountain slopes, this construction method also greatly saves the demand for construction machinery and construction sites for bored pile construction in complex terrains, reduces construction labor costs, and all materials of the steel trestle 2 can be disassembled, and the steel sheet piles 201 can be pulled out for turnover use. All materials only need to be rented and do not need to be processed by themselves, which greatly saves the cost of use.

[0058] In another technical solution, the steel trestle 2 includes two parallel and symmetrically arranged rail frames 20, and a single rail frame 20 includes a plurality of spaced steel sheet piles 201. The pile bodies of the steel sheet piles 201 are in the slope, and the tops of all the steel sheet piles 201 are commonly connected to a steel track 21. All sections of the steel track from the highest point to the lowest point are downhill sections or horizontal sections.

[0059] In the present technical solution, the steel sheet pile 201 is a single H-shaped I-beam. The spacing and size of the H-shaped I-beam on a single rail frame 20 need to be determined based on the terrain, geology and planned load. In addition to the H-shaped I-beam, the steel sheet pile 201 can also be a steel pipe steel sheet pile or a Larsen steel sheet pile, and the number of rail frames 20 can also be increased according to actual needs. The steel track 21 always remains downhill or horizontal from the top of the slope 6 to the bottom of the slope 6, so that the first movable platform 1 can use its own weight to slide down from the top of the slope 6 to the bottom of the slope 6 on the steel trestle 2. The distance between each section of the steel track 22 and the slope 6 must be strictly calculated to avoid structural instability or local plastic failure of the steel trestle 2 during construction.

[0060] In another technical solution, the first movable platform 1 includes a steel frame platform 11, which is assembled from multiple groups of Bailey beams 110. A steel plate layer 111 is detachably connected to the Bailey beam 110, and a platform bracket 12 is detachably connected thereto. The platform bracket 12 is located above the steel rail 21 and includes two horizontal bracket main beams 121 parallel to the rail frame 20. A plurality of bracket secondary beams 122 are detachably connected between the upper surface of the bracket main beam 121 and the steel frame platform 11, and a traction bracket 13 is detachably connected to the bottom surfaces of the plurality of bracket secondary beams 122. The platform bracket 12 is connected to the traction bracket 13, which is connected to the winch equipment 3 via a steel cable 31. The platform bracket 12 is connected to a hydraulic wheel group 14, which is in contact with the steel rail 21 below.

[0061] In this technical solution, the Bailey beam frame 110 of the steel frame platform 11 is composed of multiple groups of Bailey trusses arranged in parallel, and the Bailey trusses in parallel are connected by at least two Bailey truss beams. The steel plate layer 111 is composed of multiple rectangular steel plates, and the steel plates are directly mechanically connected to the Bailey beams below by bolts or tenons. A personnel fence 112 is set around the upper surface of the steel plate layer 111. The steel frame platform 11 has minimal deformation when bearing loads and can evenly transfer the load of the steel plate layer 111 downward to the The platform support 12 has a support secondary beam 122, and the support secondary beam 122 distributes the load to the support main beam 121. The traction support 13 is connected to multiple support secondary beams 122 and has multiple lifting points to connect the steel cable 31. The hydraulic wheel group 14 can independently carry the platform support 12, the steel frame platform 11 and the load thereon while traveling on the steel track 21. When the first movable platform 1 moves, the hydraulic wheel group 14 can rely on its own hydraulic rods to extend and retract so that the platform support 12 thereon always remains level.

[0062] In another technical solution, the steel rail 21 includes a plurality of steel corbels 211 arranged at intervals, and a steel rail beam 212 is connected between any two steel corbels 211. The steel corbels 211 correspond one-to-one to the top ends of the steel sheet piles 201 and are detachably connected. The top surfaces of the steel corbels 211 are flat and flush with the top surfaces of the steel rail beams 212 on both sides at the joints without any height difference. The vertical surface of the steel corbel 211 close to the other side of the steel rail 21 is flush with the vertical surface of the steel rail beam 212 close to the other side of the steel rail 21. The individual steel track beams 212 are processed in batches according to different slopes and required lengths. The steel track beams 212 are H-shaped I-steels with a flat surface upward and supplemented with stiffening ribs. Other forms of rails can also be used. The steel brackets 211 are connected to the steel track beams 212 by high-strength bolts. The steel brackets 211 are connected to the steel sheet piles 201 by high-strength bolts. The upper surface of the steel track 21 is flat so that the first movable platform 1 can travel smoothly. A plurality of rail connecting beams 22 are connected between the two rail frames 20, which are perpendicular to the rail frames 20. It is arranged horizontally, and both ends of the rail connecting beam 22 are detachably connected to the steel corbels 211 on both sides. The top surface of the rail connecting beam 22 is lower than the top surface of the connected steel corbel 211. A supporting pulley 220 is fixed to the top surface of the rail connecting beam 22. Each supporting pulley 220 can support a corresponding steel cable 31. The supporting pulley 220 is set at the place where the slope of the steel track 21 changes. Whenever the first movable platform 1 slides down to an area with a larger slope, the steel cable 31 is naturally placed on the supporting pulley 220, and the supporting pulley 220 acts as a fulcrum.

[0063] In another technical solution, the support main beam 121 is located directly above the steel rail 21 on each side, and a plurality of support bases 15 are detachably connected to the bottom surface of the support main beam 121, which correspond one-to-one to the steel corbels 211 below. There is a hydraulic jack 16 between the bottom surface of the support base 15 and the top surface of the steel corbel 211, and its height is equal to the net distance between the bottom surface of the support base 15 and the top surface of the steel corbel 211.

[0064] In the present technical solution, since the intervals between any two adjacent steel sheet piles 201 are the same, when assembling the first movable platform 1, the multiple support bases 15 connected to the same support main beam 121 are also arranged in this manner, and the intervals between them are used as the length modulus of the horizontal movement distance of the first movable platform 1, so that when the first movable platform 1 is in any position, all support bases 15 can correspond one-to-one with the nearest steel corbel 211, and there is a hydraulic jack 16 between each support base 15 and the steel corbel 211 below it. The top surfaces of all hydraulic jacks 16 are at the same level to ensure that the upper platform support 12 remains horizontal, and the hydraulic jacks 16 are only installed when the first movable platform 1 is fixed to the steel rail 21, and are manually disassembled before the first movable platform 1 slides down or is pulled up.

[0065] In another technical solution, installing the first movable platform 1 and connecting it to the hoist device 3 with a steel cable 31 to complete the entire steel trestle 2 includes the following steps:

[0066] A1. Use a steel sheet pile driver 41 to construct steel sheet piles 201 at the top of the slope 6 within the range covered by its cantilever. Then install a steel bracket 211 on the top of each completed steel sheet pile 201, and connect the steel track beam 212 and the rail connecting beam 22 between the steel brackets 211. Specifically:

[0067] According to the construction site environment, a construction site is first leveled at the top of the relatively flat slope 6. The required materials are transported to the construction site. The first few rows of steel sheet piles 201 are constructed at the top of the slope 6 using a steel sheet pile driver 41. The steel brackets 211, steel track beams 212, and rail coupling beams 22 are manually connected. To ensure rapid on-site construction, all connection measures should be connected using high-strength bolts.

[0068] A2. Using the upper surface of the steel bracket 211 as the base, place each hydraulic jack 16 on each steel bracket 211 so that the top surface of each hydraulic jack 16 is at the same level. Install the platform support 12, traction support 13, steel frame platform 11, and hydraulic wheel assembly 14 in sequence. Then, connect the traction support 13 and the winch device 3 with a steel cable. Move the required steel sheet pile driver 41 onto the steel frame platform 11. Specifically:

[0069] When the first movable platform 1 is fixed on the steel trestle 2, the hydraulic jack 16 is always under pressure, and the platform bracket 12, the traction bracket 13, and the steel frame platform 11 are all connected with high-strength bolts.

[0070] A3. The winch device 3 straightens the steel cable 31 and applies force. At this time, the hydraulic wheel assembly 14 is kept raised and adjusted in time to ensure that the support platform 12 is always level. After removing the hydraulic jacks 16, the winch device 3 is used to lower the steel cable 31 so that the first movable platform 1 moves to the appropriate position under its own weight. While maintaining the tension of the winch device 3, the steel cable 31 is stopped from being lowered to prevent the first movable platform 11 from sliding downward. The hydraulic jacks 16 are installed between the support base 15 and the steel bracket 211. After installation, the hydraulic wheel assembly 14 is retracted so that the platform support 12 rests on the hydraulic jacks 16. Specifically:

[0071] Before the hydraulic wheel group 14 is lifted, the necessary equipment and materials required for subsequent construction must be installed and stacked on the first movable platform 1, and then the winch device 3 is used to tighten the steel cable 31 and lock the length of the steel cable 31. When the hydraulic wheel group 14 is in the lifted state, the load borne by the hydraulic jack 16 is monitored at any time. When the total load borne by all hydraulic jacks 16 returns to zero, the hydraulic jack 16 is removed, and thereafter the winch device 3 can be operated to complete the movement of the first movable platform 1. When the first movable platform 1 is moved to the appropriate position, the winch device 3 is fine-tuned so that the bracket base 15 and the steel bracket 211 are aligned one by one, and the hydraulic jack 16 is placed therein. After locking the winch device 3, the hydraulic wheel group 14 is slowly retracted, and the force applied to the hydraulic wheel group 14 is monitored at any time. When the overall load of the hydraulic wheel group 14 is 0, the first movable platform 1 can be regarded as fixed to the steel trestle 2, and the steel cable 31 can be removed at this time.

[0072] A4. Repeat A1 and A3 to extend to the bottom of slope 6 and complete the construction of steel trestle 2. Specifically:

[0073] It can be flexibly decided according to traffic conditions and site conditions whether to construct the steel trestle from the top of the slope 6 to the bottom of the slope 6 or from the bottom of the slope 6 to the top of the slope 6. When the steel trestle 2 is constructed from the bottom of the slope 6 to the top of the slope 6, other processes remain unchanged. It is only necessary to change the process of the first movable platform 1 sliding down under the control of the winch device 3 to the process of pulling up under the control of the winch device 3.

[0074] In another technical solution, the hoisting of the pile reinforcement cage 51 into all the pile holes 5 includes the following steps:

[0075] B1. Lower the first movable platform 1 carrying the lifting device 43 to a suitable position, install the hydraulic jack 16, retract the hydraulic wheel assembly 14, and disconnect the steel cable 31 between the first movable platform 1 and the hoist device 3;

[0076] B2. Install the second movable platform 12, place the pile reinforcement cage placement frame 430 on it, and connect the hoist device 3 to the second movable platform 12 cable 31. Specifically:

[0077] The second movable platform 12 acts as a material transportation function when the first movable platform 1 is fixed. Its platform structure is equivalent to that of the first movable platform 2, and its table top can be made larger to better complete the transportation task. To ensure safety, under normal circumstances, only one movable platform can be connected to the winch device 3 at the same time on the same steel trestle 2, and the other platforms remain fixed. The position of the lifting point on the traction bracket 13 needs to be further designed. When any movable platform is connected to the winch device 3, no matter whether the movable platform is pulled up or slid down, the steel cable 31 will not contact other movable platforms above.

[0078] B3. Arrange a batch of pile reinforcement cages 51 on the pile reinforcement cage placement rack 430 using the lifting equipment 43 at the top of the slope 6. Specifically:

[0079] The length of a single pile reinforcement cage 51 is controlled at 4-6M. In order to allow more pile reinforcement cages 51 to be stacked on the second movable platform 10 within a safe range, the pile reinforcement cage placement frame 430 is a stacking bracket made of steel sections, which can place multiple layers and columns of pile reinforcement cages 51 at intervals and ensure stability after stacking.

[0080] B4. Use the hoisting device 3 to lower the second movable platform 10 to the first movable platform 1 within the lifting coverage area of ​​the lifting device 43. Specifically:

[0081] The lifting equipment 43 needs to determine the equipment adoption plan based on actual needs and the load-bearing capacity of the first movable platform 1. A fixed rotatable crane can be installed, or a crawler crane can be used. Before the lifting process, the lifting equipment 43 and the steel frame platform 11 need to be fixed in place. If the lifting load is large, additional fixing tooling is required in the steel frame platform 11 and then the lifting equipment 43 is connected to the fixed tooling to serve as a ground anchor when the equipment is operating on level ground.

[0082] B5. The lifting device 43 lifts all the pile reinforcement cages 51 on the second movable platform 10 in sequence and places them into the pile holes 51 within the lifting area. After completion, the second movable platform 10 is raised to the top of the slope 6. Steps B3-B4 are repeated until all the reinforcement cages 51 within the lifting area are completed.

[0083] In another technical solution, the hydraulic wheel group 14 includes two groups of symmetrical single-sided support wheel groups 141, which are connected to the lower surface of the support main beam 12. The single-sided support wheel group 141 includes multiple electric hydraulic cylinders 1411. The electric hydraulic cylinders 1411 are arranged at intervals and vertically fixed to the bottom surface of the support main beam 121. The end bearing of the hydraulic telescopic rod 1412 of each electric hydraulic cylinder 1411 is hinged with a distribution wheel frame 142. The distribution wheel frame 142 is in the shape of an upward convex crank. The surface bearing of the distribution wheel frame 142 facing the proximal steel rail 21 is connected to two traveling wheels 143, and the form wheel 143 is in contact with the top surface of the steel rail 12.

[0084] In this technical solution, in order to ensure the carrying capacity and stability of the platform, the hydraulic wheel group 14 adopts a four-cylinder hydraulic support, including four electric hydraulic cylinders 1411, and a hydraulic telescopic rod 1412 stroke sensor of each electric hydraulic cylinder 1411, multiple inclination sensors, etc. The inclination sensor can be fixed in the steel frame platform 11 to monitor the inclination angle of the steel frame platform 11 in real time, and then adjust the stroke of the hydraulic rod 1412 in time to control the horizontality of the steel frame platform 11. The distribution wheel frame 142 hinged to the single-sided support wheel group 141 evenly distributes the load on it to each roller 143. The distribution wheel frame 142 evenly distributes the load to the rollers 143 thereon to reduce the maximum bending moment of the steel track 21. The rollers 143 arranged front and back on a single distribution wheel frame 142 can better adapt to the bending section of the steel track 21, so that the first movable platform 1 can travel smoothly on the steel trestle 2.

[0085] In this technical solution, according to the load distribution on the first movable platform 1, an inclined hydraulic cylinder 144 can be added between the support secondary beam 122 and any distribution wheel frame 142. The two ends of the inclined hydraulic cylinder 144 are respectively hinged to the support secondary beam 122 and the distribution wheel frame 142 bearings, so as to meet the integrity of the hydraulic wheel group 14 and make the load transmitted by the hydraulic wheel group 14 to the steel trestle 2 evenly distributed.

[0086] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A pile foundation construction method, characterized in that: The following steps are involved: S1. According to the designed position of the pile foundation on the slope, survey and mark the positions where the steel sheet piles need to be installed on both sides of the pile position within a straight line from the top of the slope to the bottom of the slope; S2, fix the hoisting device on the top of the slope, install the first movable platform and connect it to the hoisting device with a steel cable, and complete the entire steel trestle; S3, moving or driving the drilling equipment to the first movable platform, using the winch equipment to drive the first movable platform to the designed position on the steel trestle, fixing the first movable platform to the steel trestle, and then using the drilling equipment to perform pile hole construction at the pile position; S4, repeat S3 until all pile holes in the area covered by the steel trestle are drilled, and then unload the drilling equipment from the first movable platform; S5, moving or driving the hoisting equipment to the first movable platform, and hoisting the pile reinforcement cage into all pile holes; S6. Pour concrete into the pile hole to complete the construction of the pile foundation.

2. The pile foundation construction method according to claim 1, characterized in that: The steel trestle comprises two parallel and symmetrically arranged rail frames, a single rail frame comprises a plurality of spaced steel sheet piles, the pile bodies of the steel sheet piles are in the slope, the tops of all the steel sheet piles are connected to a steel track, and all sections of the steel track from the highest point to the lowest point are downhill sections or horizontal sections.

3. The pile foundation construction method according to claim 2, characterized in that: The first movable platform includes a steel frame platform, which is assembled from multiple groups of Bailey beams. A steel plate layer is detachably connected to the Bailey beams, and a platform bracket is detachably connected thereunder. The platform bracket is located above the steel trestle, and includes two horizontal bracket main beams parallel to the rail frames. A plurality of bracket secondary beams are detachably connected between the upper surface of the bracket main beam and the steel frame platform, and a traction bracket is detachably connected to the bottom surfaces of the plurality of bracket secondary beams, which is connected to the winch equipment by a steel cable. The platform bracket is connected to a hydraulic wheel set, which is in contact with the steel track below.

4. The pile foundation construction method according to claim 3, characterized in that The steel track includes a plurality of steel corbels arranged at intervals, a steel track beam is connected between any two steel corbels, the steel corbels correspond to the top ends of the steel sheet piles one by one and are detachably connected, the top surfaces of the steel corbels are flat and flush with the top surfaces of the steel track beams on both sides at the joints without any misalignment in height, and the vertical surface of the steel corbel close to the steel track on the other side is flush with the vertical surface of the steel track beam close to the steel track on the other side.

5. The pile foundation construction method according to claim 4, characterized in that: The support main beams are located directly above the steel rails on each side. The bottom surface of the support main beam is detachably connected with multiple support bases, which correspond one-to-one to the steel corbels below. There is a hydraulic jack between the bottom surface of the support base and the top surface of the steel corbel, and its height is equal to the net distance between the bottom surface of the support base and the top surface of the steel corbel.

6. The pile foundation construction method according to claim 5, characterized in that: Installing the first movable platform and connecting it to the hoisting equipment with steel cables to complete the full section of the steel trestle includes the following steps: A1. Use a steel sheet pile driver to construct steel sheet piles within the coverage of its cantilever at the top of the slope, then install steel brackets on the top of each completed steel sheet pile, and connect the steel track beam and rail connecting beam between the steel brackets; A2. With the upper surface of the steel bracket as the bottom, place each hydraulic jack on the steel bracket and make the top surfaces of each hydraulic jack at the same level, install the platform bracket, traction bracket, steel frame platform, hydraulic wheel set in sequence, then connect the traction bracket and the winch equipment with a steel cable, and move the required steel sheet pile driver to the steel frame platform; A3. The winch equipment straightens the steel cable and puts stress on it. At this time, keep the hydraulic wheel group lifted and adjust itself in time to make the support platform always level. After removing the hydraulic jacks, use the winch equipment to lower the steel cable so that the first movable platform slides down to an appropriate position under the action of its own weight. While maintaining the pulling force of the winch equipment, stop lowering the steel cable so that the first movable platform stops sliding down. Install the hydraulic jacks between the support base and the steel bracket. After installation, retract the hydraulic wheel group so that the platform support sits on the jacks. A4. Repeat A1 and A3 to extend to the bottom of the slope and complete the steel trestle.

7. The pile foundation construction method according to claim 5, characterized in that: The installation of pile reinforcement cages into all pile holes includes the following steps: B1. Lower the first movable platform carrying the lifting equipment to a suitable position, install the hydraulic jack, retract the hydraulic wheel set, and release the steel cable connection between the movable platform and the winch equipment; B2, installing the second movable platform, placing the pile reinforcement cage placement frame on it and connecting the hoisting machine equipment with the second movable platform steel cable; B3. Arrange a batch of pile reinforcement cages on the pile reinforcement cage placement rack at the top of the slope; B4. Use the hoisting equipment to lower the second movable platform to the lifting coverage area of ​​the lifting equipment on the first movable platform; B5. The lifting equipment lifts all the pile reinforcement cages on the second movable platform in sequence and places them into the pile holes within the lifting area coverage. After completion, the second movable platform is raised to the top of the slope, and steps B3-B4 are repeated until the construction of all reinforcement cages within the lifting area coverage is completed; B6. Repeat B1-B3 until all pile reinforcement cages are constructed.

8. The pile foundation construction method according to claim 7, characterized in that: The hydraulic wheel group includes two groups of symmetrical single-sided support wheel groups, which are connected to the lower surface of the support main beam. The single-sided support wheel group includes multiple electric hydraulic cylinders, which are arranged at intervals and vertically fixed to the bottom surface of the support main beam. The hydraulic telescopic rod end bearing of each electric hydraulic cylinder is hinged with a distribution wheel frame, and the distribution wheel frame is in the shape of a crank convex upward. The surface bearing of the distribution wheel frame facing the proximal steel track is connected to two running wheels, and the running wheels are in contact with the top surface of the steel track.

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