Gantry-type piling machine and cast-in-situ pile construction method

Abstract

The present disclosure relates to the technical field of pile foundation construction, and provides a gantry-type piling machine and a cast-in-situ pile construction method. The gantry-type piling machine comprises a gantry, a pile frame platform, a moving assembly, and a lifting assembly. The gantry is vertically arranged on one side of the pile frame platform, and a power head is mounted on the gantry. A feeding position is provided on the pile frame platform, and the projection of a center shaft of the power head on the pile frame platform is located in an extension direction of the feeding position. The moving assembly is arranged on one side or two sides of the feeding position, a plurality of drill rods are horizontally distributed on the moving assembly, and each drill rod is perpendicular to the plane where the gantry is located. The moving assembly is used for conveying the plurality of drill rods to the feeding position in sequence. The lifting assembly comprises a pickup part, the pickup part is used for grabbing the drill rod, and the lifting assembly is used for driving the drill rod to be switched from a horizontal state to a vertical state and move to a position below the power head. According to the gantry-type piling machine, ordered rod connection can be realized by means of mutual cooperation of the moving assembly and the lifting assembly, and counterweighting can be performed on the piling machine by horizontally distributing the plurality of drill rods on the moving assembly so as to ensure the stability of the piling machine.

Description

Gantry pile driver and cast-in-place pile construction method

[0001] Cross-references to related publications

[0002] This disclosure claims priority to Chinese patent application number 2023109596160 filed with the State Intellectual Property Office on July 31, 2023, entitled “Gantry Pile Driver and Cast-in-Place Pile Construction Method”, and claims priority to Chinese patent application number 2023220501055 filed with the State Intellectual Property Office on July 31, 2023, entitled “Gantry Pile Driver”, the entire contents of the above two patent applications are incorporated into this disclosure by reference. Technical Field

[0003] The present disclosure relates to the technical field of pile foundation construction, and in particular to a portal pile driver and a cast-in-place pile construction method. Background Art

[0004] Pile foundation engineering is a sub-project in construction engineering. Its purpose is to increase the bearing capacity of the natural soil of the building foundation by adding pile foundations, or to directly transfer the upper load of the building to the solid and strong soil layer through the pile foundation, so that the bearing capacity of the building foundation meets the safety requirements.

[0005] Pile foundations are rods made of concrete, steel, and other load-bearing materials. They are typically cylindrical or square, but in recent years, special-shaped piles with full-length threads, partial threads, and partial expansions have also been developed. Based on the construction process, pile foundations are divided into two categories: precast piles and cast-in-place piles. Precast piles are prepared outside the construction area, while cast-in-place piles are constructed by drilling holes and pouring concrete in the construction area.

[0006] Among them, the machinery used for the construction of cast-in-place piles is a pile-driving machine, which is equipped with a hollow drill tool. The drill tool is used to drill holes in the soil of the construction area and to serve as a channel for pouring concrete during the process of lifting the drill tool. The drill tool can be used to form concrete (or other pouring materials) in one go to form a pile foundation. Pile-driving machinery, both domestically and internationally, falls into two broad categories: one is a traditional pile driver whose column and drill tool lengths meet the design requirements for the pile foundation. During operation, the drill tool must be perpendicular to the ground, then lowered to drill a hole. The hole is then lifted and concrete is poured into the pile. In this case, the overall length of the column supporting the drill tool and the drill tool must exceed the designed pile length. The other type of pile driver utilizes multiple drill rods attached to the side of the column to meet the design requirements. In some implementations, the drill rod with a drill bit is attached to the column, and one or more additional drill rods are attached to the side of the existing drill rod on the column to connect with the existing drill rod if the drilling depth is insufficient. The former type is more mature in construction and occupies a large market share, while the latter represents a new type of pile driver that has emerged in the past decade, such as those disclosed in CN216381270U, ​​CN105756060A, and CN107023267B.

[0007] The first type of traditional pile driver, limited by the combined length of the pile driver column and drill tool, has never been built higher than 80 meters. For example, if the pile foundation is designed to be 60 meters long, the total drill tool length must be greater than 60 meters. Because the pile foundation also requires guide rails to facilitate lowering and lifting the drill tool, the columns supporting the rails are even longer. Furthermore, since the drill tool must be perpendicular to the ground when operating, and the column also houses a power head weighing 10 to 20 tons in addition to the drill tool, a traditional pile driver forms a towering column structure exceeding tens of meters in height. When the power head is at the top of the column, the center of gravity of the entire pile driver is extremely high, and collapse is common. For this reason, traditional pile drivers with excessively high columns have been banned in some regions.

[0008] While the second type of pile driver can reduce the height of the pile driver column and thus the risk of collapse by pre-arranging multiple drill rods vertically and then connecting them, this type of pile driver is currently mostly used in the construction of lightweight, small-diameter pile foundations, where the drill rods used in the pile foundation can often be pulled by one person. However, when constructing pile foundations with a diameter of 400 mm or larger, the length and weight requirements of each drill rod in the drilling tool also increase accordingly (the weight of the drill rod is dozens of times that of the drill rod used in the above-mentioned lightweight, small-diameter pile foundation construction, weighing 3-6 tons). Therefore, even though CN216381270U, ​​CN105756060A, and CN107023267B disclose solutions for standing up spare drill rods for use, in actual applications, drill rods are heavy components, and each erected drill rod weighs several tons, resulting in a high center of gravity and poor stability of the drill tool, making it very easy for the drill tool to collapse and cause injuries. In addition, the drill tool places greater demands on the strength of the pile driver's frame mechanism, requiring more materials and higher costs. Therefore, the pile drivers of related technologies still find it difficult to meet the construction requirements of large-diameter and heavy-duty pile foundations. In addition, since the contact area between the drill tool and the pile driver body is small when placed upright, the concentrated force area has a high pressure, and the structural strength of the pile driver equipped with heavy drill tools will also be greatly increased.

[0009] Furthermore, regarding the second type of pile driver, CN202688997U discloses a dual-purpose, long-screw, fully automatic pile driver that can increase the pile driving depth by 15 meters without increasing the height of the pile driver. However, it only discloses a column mechanism that can rotate axially to switch between drilling and cage lowering states, and does not disclose how the drilling tool is improved or how the spare drill rod is connected to the original drill rod. CN208950504U discloses a combined power-driven pile driver, which discloses two sets of power heads and drilling tools arranged vertically along the column. When the first set of drilling tools reaches the end of the power head system's travel, the drill tool is disconnected from the power head. A slide rail assembly then connects the first set of drilling tools to the second set of power heads and drilling tools to increase the pile driving depth. However, the addition of a power head and drilling tool system increases the weight of the column top, making it more likely that the machine will fall over. Furthermore, the power head is typically the most expensive component of a pile driver, and having two sets of power heads would undoubtedly significantly increase the manufacturing cost of the pile driver. CN209556966U discloses a base device for an automated well repair rig on an offshore platform, which transports the oil pipe to a robotic arm through a pipe-lifting mechanism, and then lifts the oil pipe through the robotic arm and sends it into the well. During this process, other auxiliary equipment is required to ensure a continuous supply of oil pipes. However, since the oil pipe is a lightweight component, and a 6-8 meter long drill bit on a pile driver weighs about 4-6 tons, if the oil pipe transportation method disclosed therein is used, that is, the drill bit is transported by free fall into the robotic arm and the well, it will damage the mechanical structure and drill bit of the pile driver. In addition, the transportation method disclosed therein also requires auxiliary machinery such as cranes and manual cooperation, which will greatly increase costs. Therefore, the oil pipe transportation method disclosed by CN209556966U is not suitable for heavy pile drivers. In addition, in order to ensure the balance of the pile driver, CN110939132A proposes a counterweight device, which can adjust the extension and contraction of the oil cylinder to change the filling space of the counterweight outer frame, and at the same time add or reduce the counterweight blocks, so that the verticality of the machine is guaranteed. However, the process of adding or reducing the counterweight blocks is relatively cumbersome, not only time-consuming and labor-intensive but also requires other auxiliary machinery, which greatly affects the continuity of the pile driving construction and increases costs.

[0010] Based on this, for safety and reliability reasons, there is currently no reliable technology to solve the problem of how a pile driver equipped with heavy drilling tools can still achieve stable rod connection and ensure the stability of the pile driver after pre-parallelizing multiple drill rods. Therefore, how to achieve stable rod connection and maintain the stability of the pile driver in a pile driver equipped with heavy drilling tools remains a difficult technical problem to overcome.

[0011] Summary of the Invention

[0012] The present disclosure provides a gantry pile driver and a bored pile construction method to alleviate technical problems existing in related technologies. In related technologies, a pile driver is equipped with multiple vertical drill rods parallel to the original drill rod on one side of a column. When used in the construction of large-diameter heavy pile foundations, the weight and length of each drill rod need to be increased accordingly, resulting in a technical problem that the drill rod connection process in the pile driver is difficult and the stability of the pile driver is difficult to ensure.

[0013] In some embodiments, the present disclosure provides a gantry pile driver that may include a gantry, a pile frame platform, a moving assembly, and a lifting assembly;

[0014] The gantry can be erected on one side of the pile frame platform, and a power head that can be raised and lowered can be installed on the gantry, and the power head can be detachably connected to one end of any drill rod moved below it;

[0015] A loading position may be provided on the pile frame platform at one side of the gantry, and a projection of the central axis of the power head on the pile frame platform may be located in the extension direction of the loading position;

[0016] The moving assembly may be provided on one or both sides of the material loading position, and a plurality of drill rods may be horizontally distributed on the moving assembly, and each of the drill rods may be perpendicular to the plane where the gantry is located; the moving assembly may be used to move on a horizontal plane in a direction parallel to the plane where the gantry is located, so as to transport the plurality of drill rods to the material loading position in sequence;

[0017] The lifting assembly may include a picking piece, which can be used to grab the drill rod at the upper material position. The lifting assembly can be used to rotate relative to the pile frame platform to drive the drill rod grabbed by the picking piece to switch from a horizontal state to an upright state and move it under the power head during the rotation.

[0018] In an optional embodiment, the moving assembly may include a plurality of sliding mechanisms, and the plurality of sliding mechanisms may be spaced apart in a direction perpendicular to the plane where the gantry is located, and the plurality of sliding mechanisms may be used to support the plurality of drill rods and drive the plurality of drill rods to move;

[0019] Along a direction perpendicular to the plane where the gantry is located, the picking pieces at the loading position and the plurality of sliding mechanisms may be distributed alternately.

[0020] In an optional embodiment, the sliding mechanism may be a telescopic structure, and the sliding mechanism may be used to drive the drill rod it supports to rise and fall during the telescopic process.

[0021] In an optional embodiment, the pile frame platform may be provided with a plurality of guide rails, the plurality of guide rails may be spaced apart in a direction perpendicular to the plane where the gantry is located, and each of the guide rails may extend in a direction parallel to the plane where the gantry is located;

[0022] The plurality of sliding mechanisms may be slidably connected to the plurality of guide rails in a one-to-one correspondence.

[0023] In an optional embodiment, each of the sliding mechanisms may be provided with a first latching position and a second latching position distributed at intervals, the first latching positions of multiple sliding mechanisms may be distributed on the same straight line to support the same drill rod, and the second latching positions of multiple sliding mechanisms may be distributed on the same straight line to support the same drill rod.

[0024] In an optional embodiment, the lifting assembly may include a mechanical arm and a lifting drive mechanism, and the picking member may be a mechanical gripper;

[0025] The mechanical arm may include an articulated end and a suspended end, the articulated end of the mechanical arm may be articulated to the pile frame platform, and the suspended end of the mechanical arm may be suspended in the air;

[0026] The mechanical gripper can be mounted on the mechanical arm, the output end of the jacking drive mechanism can be connected to the mechanical arm, and the jacking drive mechanism can be used to drive the mechanical arm to rotate relative to the pile frame platform so that the mechanical arm can switch between a horizontal state and an upright state.

[0027] In an optional embodiment, the hinged end of the robotic arm can be located between the gantry and the loading position, and the mechanical clamp can be installed on the arm surface of the robotic arm facing away from the pile frame platform, or the mechanical clamp can be installed on the arm surface of the robotic arm facing the pile frame platform, and a turntable mechanism can be installed on the pile frame platform, and the hinged end of the robotic arm can be hinged to the turntable mechanism, and the turntable mechanism can be used to drive the robotic arm to rotate about the center axis of the robotic arm.

[0028] In an optional embodiment, a side of the pile frame platform on which the gantry is provided may be connected to an extension frame, the hinged end of the robotic arm may be hinged to the extension frame, and the robotic arm may pass through the gantry during rotation relative to the pile frame platform and then stand upright on a side of the gantry facing away from the loading position;

[0029] The mechanical gripper may be mounted on an arm surface of the mechanical arm facing the pile frame platform.

[0030] In an optional embodiment, a self-adjusting counterweight assembly, a monitoring system, and a control system are also included;

[0031] The self-adjusting counterweight assembly may be mounted on a side of the pile frame platform away from the gantry, and the self-adjusting counterweight assembly may include a moving portion capable of moving in a direction perpendicular to a plane where the gantry is located;

[0032] The self-adjusting counterweight assembly and the monitoring system can both be connected to the control system. The monitoring system can be used to monitor the weight changes at the gantry of the gantry pile driver. The control system can be used to calculate the movement amount of the mobile part based on the weight changes monitored by the monitoring system, and can drive the mobile part to move in a direction perpendicular to the plane of the gantry according to the movement amount.

[0033] The number of the moving components may be an even number, and the moving components may be divided into two groups and may be symmetrically distributed on both sides of the loading position.

[0034] The power head and the drill rod can be connected via a joint assembly with an elastic pin and a slot.

[0035] The power head may be provided with a positioning member, and the positioning member may be configured to abut against a circumferential side wall of the drill rod when the drill rod is erected below the power head to limit the position of the drill rod.

[0036] The gantry can be composed of two parallel columns and a crossbeam vertically connected between the two columns. The columns can be formed by a fixed rod and a lifting rod in a sliding connection. The power head can be fixedly connected to the lifting rod.

[0037] In other embodiments, the present disclosure provides a cast-in-place pile construction method, which can be applied with the gantry pile driver described in any of the aforementioned embodiments, and can include:

[0038] S1: starting the moving assembly to transport one of the drill rods on the moving assembly to the loading position;

[0039] S2: starting the lifting assembly to enable the picking member to grab the drill rod at the loading position, and rotating the lifting assembly after the moving assembly moves away from the loading position to drive the drill rod grabbed by the picking member to switch from a horizontal state to a vertical state and move it to under the power head;

[0040] S3: connecting the top end of the drill rod grasped by the pickup member to the power head, and then causing the pickup member to release the grasped drill rod;

[0041] S4: driving the power head downward, moving the drill rod connected to the lower portion of the power head to the top of the drill rod buried at the designed pile position of the cast-in-place pile, and then connecting the bottom end of the drill rod connected to the lower portion of the power head to the top end of the buried drill rod:

[0042] S5: Continue to drive the power head downward and start the power head, so that the drill rod connected to the lower side of the power head rotates and drills into the soil at the designed pile position of the cast-in-place pile;

[0043] S6: Separate the power head from the drill pipe connected thereto, and then drive the power head upward;

[0044] S7: Repeat steps S1-S6 to sequentially connect the multiple drill rods on the mobile assembly and drill them into the soil at the designed pile position of the cast-in-place pile.

[0045] In other embodiments, the cast-in-place pile construction method of the present disclosure may further include the following steps before step S1:

[0046] S01: moving the gantry pile driver to a bored pile construction area, and positioning the power head on the gantry of the gantry pile driver above a designed pile position of the bored pile;

[0047] S02: Connecting the drill rod with the drill bit below the power head on the gantry of the gantry pile driver, lowering the power head and starting the power head to drive the drill rod with the drill bit to rotate and drill into the soil at the designed pile position of the cast-in-place pile.

[0048] The gantry pile driver provided by the present invention may include a gantry, a pile frame platform, a moving assembly and a lifting assembly; the gantry may be erected on one side of the pile frame platform, and a power head that can be raised and lowered may be installed on the gantry, and the power head can be detachably connected to one end of any drill rod moved thereunder; a loading position may be provided at a position on one side of the pile frame platform, and the projection of the central axis of the power head on the pile frame platform may be located in the extension direction of the loading position; a moving assembly may be provided on one or both sides of the loading position, and a plurality of drill rods may be horizontally distributed on the moving assembly, and each drill rod may be perpendicular to the plane where the gantry is located; the moving assembly may be used to move in a direction parallel to the plane where the gantry is located on a horizontal plane to transport a plurality of drill rods to the loading position in sequence; the lifting assembly may include a picking piece, which may be used to grab the drill rod at the loading position, and the lifting assembly may be used to rotate relative to the pile frame platform to drive the drill rod grabbed by the picking piece to switch from a horizontal state to a vertical state and move it to under the power head during the rotation process. The gantry pile driver provided herein can be used for constructing cast-in-place piles, and is particularly suitable for constructing longer cast-in-place piles. To reduce the height of the pile driver, the drilling tool adapted for the gantry pile driver can be divided into multiple drill rods, one of which is equipped with a drill bit. This drill rod with a drill bit is considered the original drill rod, and the remaining drill rods are spare drill rods. Before constructing the cast-in-place piles, the original drill rod can be connected to the bottom of the power head on the gantry, and multiple spare drill rods can be horizontally distributed on the mobile assembly in sequence. It should be noted that although the gantry is erected on one side of the pile frame platform and the original drill rod is connected to the bottom of the power head installed thereon, because the pile frame platform is also equipped with a mobile assembly, and the multiple spare drill rods on the mobile assembly are all horizontally distributed, a large number of upright drill rods will not accumulate on the gantry on the pile frame platform, and the center of gravity of the pile driver will not shift toward the gantry. At the same time, the multiple horizontally distributed spare drill rods can act as counterweights to balance, thereby effectively ensuring the balance and stability of the gantry pile driver. During the construction of cast-in-place piles, the spare drill rods need to be connected to the original drill rods in sequence to form a drilling tool. In some embodiments, the power head needs to be lowered on the gantry and started, so that the power head can drive the original drill rod to rotate and drill into the soil at the designed pile position. Then, the power head needs to be separated from the original drill rod and raised to its original position on the gantry to be connected to the next spare drill rod. During the process of the power head driving the original drill rod to move, the moving assembly needs to be moved horizontally on the pile frame platform in a direction parallel to the plane of the gantry to transport one of the spare drill rods to the loading position. After the spare drill rod moves to the loading position, the picking part of the lifting assembly is started so that the picking part grabs the spare drill rod at the loading position. Then, the lifting assembly is started so that the lifting assembly rotates relative to the pile frame platform. Since the projection of the central axis of the power head on the pile frame platform is located in the extension direction of the loading position, the spare drill rod grabbed by the picking part can be switched from a horizontal state to a vertical state by rotating the lifting assembly, and the spare drill rod is positioned below the power head after being erected.At this time, the power head can be connected to the spare drill rod below it, and then the pick-up part can be released and the lifting assembly can be returned to its original position. At the same time, the power head can be lowered until the spare drill rod connected below the power head is moved to the top of the original drill rod, and then the bottom end of the spare drill rod can be connected to the top of the original drill rod. The power head can then be started to drive the spare drill rod and the original drill rod to rotate at the same time, so that the spare drill rod can also be drilled into the soil at the designed pile position. Repeat the above process of moving the spare drill rod, rotating the spare drill rod, connecting the spare drill rod and the power head, lowering the power head, connecting the spare drill rod and drilling the spare drill rod into the soil. Multiple spare drill rods can be connected and drilled in turn, and finally a drilling tool formed by multiple drill rod connecting rods can be drilled into the soil at the designed pile position of the bored pile. The drilling tool can meet the design length requirements of the bored pile and can be used for the construction of cast-in-place bored piles. It should be noted that in the process of connecting multiple spare drill rods in sequence, the horizontally distributed spare drill rods on the pile frame platform that have not yet moved to the loading position can continue to act as counterweights to ensure the balance and stability of the gantry pile driver. At the same time, since each spare drill rod will be drilled into the soil after the connection, the weight at the gantry will not continue to increase as the connection operation proceeds. Even if the connection operation enters the later stage and there are no longer horizontal spare drill rods distributed on the pile frame platform, the center of gravity of the gantry pile driver will not shift beyond the gantry, and the stability of the gantry pile driver can still be guaranteed.

[0049] Compared to related technologies, the gantry pile driver provided by the present disclosure utilizes a method of horizontally placing multiple drill rods on a moving assembly that moves in an orderly manner, and using a lifting assembly to sequentially pick up and lift each drill rod point by point. This allows multiple drill rods placed horizontally at different workstations to be sequentially delivered to the same location within the portal frame (below the power head) using a single lift route. This allows the drill rod transport, rod connection, and drilling process to proceed seamlessly and orderly. Furthermore, by horizontally distributing multiple drill rods on the moving assembly, the gantry pile driver can be counterweighted to ensure stability. During the rod connection process, the post-drilling process and the horizontally distributed drill rods that have not yet been connected can be used to ensure that the center of gravity of the gantry pile driver does not deviate excessively toward the portal frame, thereby maintaining the stability of the gantry pile driver.

[0050] The bored pile construction method provided by the present disclosure uses the above-mentioned gantry pile driver, which may include: S1: starting the moving assembly to transport one of the drill rods on the moving assembly to the loading position; S2: starting the lifting assembly to enable the picking member to grab the drill rod at the loading position, and rotating the lifting assembly after the moving assembly is away from the loading position to drive the drill rod grabbed by the picking member to switch from a horizontal state to a vertical state and move it under the power head; S3: connecting the top end of the drill rod grabbed by the picking member to the power head, and then enabling the picking member to release the drill rod it has grabbed; S4: driving the The power head is lowered, and the drill rod connected below the power head is moved to the top of the drill rod buried at the designed pile position of the bored pile, and then the bottom end of the drill rod connected below the power head is connected to the top of the buried drill rod: S5: Continue to drive the power head to descend and start the power head to rotate the drill rod connected below the power head and drill into the soil at the designed pile position of the bored pile; S6: Separate the power head from the drill rod connected below it, and then drive the power head to rise; S7: Repeat steps S1-S6 to connect multiple drill rods on the moving assembly in sequence and drill them into the soil at the designed pile position of the bored pile.

[0051] The bored pile construction method provided by the present disclosure applies the above-mentioned gantry pile driver, which can achieve the same beneficial effects as the above-mentioned gantry pile driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the related technologies, the following briefly introduces the drawings required for use in the specific embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0053] FIG1 is a schematic structural diagram of a gantry pile driver according to an embodiment of the present disclosure;

[0054] FIG2 is a schematic structural diagram of a gantry pile driver and one of the spare drill rods provided in an embodiment of the present disclosure when the gantry pile driver and one of the spare drill rods are moved to a loading position;

[0055] FIG3 is a top view of the pile frame platform and a plurality of spare drill rods in FIG2 ;

[0056] FIG4 is a top view of the pile frame platform and a plurality of spare drill rods after the mobile assembly in FIG2 has returned to its original position;

[0057] FIG5 is a schematic structural diagram of a gantry pile driver when a lifting assembly is rotating according to an embodiment of the present disclosure;

[0058] FIG6 is a side view of the gantry pile driver when the lifting assembly is rotating according to an embodiment of the present disclosure;

[0059] FIG7 is a side view of the gantry pile driver when the lifting assembly is rotated to an upright position according to an embodiment of the present disclosure;

[0060] FIG8 is a schematic structural diagram of a gantry pile driver provided by an embodiment of the present disclosure when a spare drill rod is erected below the power head;

[0061] FIG9 is a schematic structural diagram of a gantry pile driver when a spare drill rod is connected below a power head according to an embodiment of the present disclosure;

[0062] FIG10 is a schematic structural diagram of a gantry pile driver according to an embodiment of the present disclosure when the power head drives the spare drill rod to descend;

[0063] FIG11 is a cross-sectional view of a moving assembly, a lifting assembly, and a spare drill rod provided in an embodiment of the present disclosure;

[0064] FIG12 is a top view of the moving assembly, lifting assembly and spare drill pipe in FIG11;

[0065] FIG13 is a cross-sectional view of a moving assembly, a lifting assembly, and a spare drill rod when one of the spare drill rods provided by an embodiment of the present disclosure is moved to a loading position;

[0066] FIG14 is a top view of the moving assembly, lifting assembly and spare drill pipe in FIG13;

[0067] FIG15 is another cross-sectional view of the moving assembly, the lifting assembly, and the spare drill pipe provided by an embodiment of the present disclosure;

[0068] FIG16 is a top view of the moving assembly, lifting assembly and spare drill pipe in FIG15;

[0069] FIG17 is another cross-sectional view of the moving assembly, the lifting assembly, and the spare drill pipe provided by an embodiment of the present disclosure;

[0070] FIG18 is a top view of the moving assembly, lifting assembly and spare drill pipe in FIG17;

[0071] FIG19 is another cross-sectional view of the moving assembly, the lifting assembly, and the spare drill pipe provided by the embodiment of the present disclosure;

[0072] FIG20 is a top view of the moving assembly, lifting assembly and spare drill pipe in FIG19;

[0073] FIG21 is a top view of a moving assembly, a lifting assembly, and a pile frame platform provided in an embodiment of the present disclosure;

[0074] FIG22 is another structural schematic diagram of a gantry pile driver provided by an embodiment of the present disclosure;

[0075] FIG23 is a partial side view of the gantry pile driver in FIG22;

[0076] FIG24 is a partial side view of the gantry pile driver in FIG22 when one of the spare drill rods is moved to the loading position;

[0077] FIG25 is a partial side view of the gantry pile driver in FIG22 when the sliding mechanism at the loading position is lowered;

[0078] FIG26 is another structural schematic diagram of a gantry pile driver provided in an embodiment of the present disclosure;

[0079] FIG27 is a schematic structural diagram of the gantry pile driver in FIG26 when the lifting assembly is rotated to an upright state;

[0080] FIG28 is a schematic structural diagram of the gantry pile driver in FIG26 when the spare drill rod in the gantry pile driver is drilling;

[0081] FIG29 is a schematic structural diagram of the gantry pile driver in FIG26 after the spare drill rod in the gantry pile driver is drilled;

[0082] FIG30 is a schematic structural diagram of the gantry pile driver in FIG26 after the spare drill rod in the gantry pile driver is drilled and the lifting assembly is reversely rotated to a horizontal state;

[0083] FIG31 is a schematic structural diagram of a gantry pile driver including a turntable mechanism provided by an embodiment of the present disclosure;

[0084] FIG32 is a schematic structural diagram of the gantry pile driver in FIG31 when the lifting assembly is rotated to a horizontal state;

[0085] FIG33 is a schematic structural diagram of the gantry pile driver in FIG31 when the lifting assembly drives one of the spare drill rods to rotate to an upright state;

[0086] FIG34 is a schematic structural diagram of the gantry pile driver in FIG31 after the turntable mechanism drives the mechanical arm to rotate;

[0087] FIG35 is a flow chart of the bored pile construction method provided in an embodiment of the present disclosure.

[0088] Icons: 1-gantry; 10-power head; 100-positioning part; 11-fixing rod; 12-lifting rod; 2-pile frame platform; 20-guide rail; 21-turntable mechanism; 22-extension frame; 3-moving assembly; 30-sliding mechanism; 300-first clamping position; 301-second clamping position; 302-pulley; 303-scissor mechanism; 304-sliding bracket; 4-lifting assembly; 40-picking part; 41-mechanical arm; 5-original drill pipe; 6-spare drill pipe; 7-travel assembly; 8-self-adjusting counterweight assembly; 9-control system. DETAILED DESCRIPTION

[0089] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. The components of the embodiments of the present disclosure generally described and shown in the drawings herein can be arranged and designed in various different configurations. The following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the disclosure claimed for protection, but merely represents selected embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0090] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0091] As shown in Figures 1 to 10, some embodiments of the present disclosure provide a gantry pile driver that may include a gantry 1, a pile frame platform 2, a moving assembly 3, and a lifting assembly 4; the gantry 1 may be erected on one side of the pile frame platform 2, and a power head 10 that can be raised and lowered may be installed on the gantry 1, and the power head 10 may be detachably connected to one end of any drill rod that moves below it; a loading position may be provided on one side of the pile frame platform 2, and the projection of the central axis of the power head 10 on the pile frame platform 2 may be located in the extension direction of the loading position; one or both sides of the loading position may be provided with The moving component 3 can be equipped with multiple drill rods distributed horizontally, and each drill rod can be perpendicular to the plane where the gantry 1 is located; the moving component 3 can be used to move in a horizontal plane in a direction parallel to the plane where the gantry 1 is located, so as to transport multiple drill rods to the loading position in sequence; the lifting component 4 can include a picking component 40, which can be used to grab the drill rod at the loading position, and the lifting component 4 can be used to rotate relative to the pile frame platform 2, so as to drive the drill rod grabbed by the picking component 40 to switch from a horizontal state to an upright state and move it to the bottom of the power head 10 during the rotation process.

[0092] The gantry pile driver provided in some embodiments of the present disclosure can be used for constructing cast-in-place piles, and is particularly suitable for constructing longer cast-in-place piles. To reduce the height of the pile driver, the drilling tool adapted for the gantry pile driver can be divided into multiple drill rods, one of which is equipped with a drill bit. This drill rod with a drill bit can be considered the original drill rod 5, and the remaining drill rods can be spare drill rods 6. Before constructing a cast-in-place pile, a drilling tool that meets the drilling depth requirements can be selected according to the designed length of the cast-in-place pile. The original drill rod 5 with a drill bit in the drilling tool can then be connected to the bottom of the power head 10 on the gantry 1, and the multiple spare drill rods 6 in the drilling tool can be placed parallel and horizontally on the mobile assembly 3. It should be noted that, although the gantry 1 can be erected on one side of the pile frame platform 2 and the original drill rod 5 can be connected to the bottom of the power head 10 installed thereon, since the pile frame platform 2 can also be provided with a mobile component 3, and the multiple spare drill rods 6 on the mobile component 3 can be distributed horizontally, at this time, a large number of upright drill rods will not be piled up at the gantry 1 on the pile frame platform 2, and the center of gravity of the pile driver will not shift toward the gantry 1. At the same time, the multiple spare drill rods 6 distributed horizontally can play a role of counterweight balancing, thereby effectively ensuring the balance and stability of the gantry pile driver.

[0093] During the construction of bored piles, the original drill rod 5 and multiple spare drill rods 6 need to be connected in sequence to form a drilling tool that meets the designed length requirements of the bored piles. In some embodiments, the gantry pile driver can first be moved to the bored pile construction area, with the power head 10 positioned above the designed pile position of the bored pile. Then, as shown in Figures 1 and 2, the power head 10 can be lowered on the gantry 1 and started, thereby using the power head 10 to drive the original drill rod 5 to rotate and drill into the soil at the designed pile position. Then, as shown in Figures 5 and 6, the power head 10 can be separated from the original drill rod 5 and raised to its original position on the gantry 1 to prepare for connection with the next spare drill rod 6. While the power head 10 can drive the original drill rod 5 to move, as shown in Figures 2 and 3, the moving assembly 3 needs to be moved horizontally on the pile frame platform 2 in a direction parallel to the plane of the gantry 1 to transport one of the spare drill rods 6 to the loading position. After the spare drill rod 6 moves to the loading position, the picking member 40 of the lifting assembly 4 can be activated so that the picking member 40 grabs the spare drill rod 6 at the loading position. Then, as shown in Figures 6 and 7, the lifting assembly 4 can be activated while the power head 10 is rising to its original position, so that the lifting assembly 4 rotates relative to the pile frame platform 2. Since the projection of the central axis of the power head 10 on the pile frame platform 2 is located in the extension direction of the loading position, the spare drill rod 6 grabbed by the picking member 40 can be switched from a horizontal state to an upright state by rotating the lifting assembly 4. At the same time, the spare drill rod 6 can be positioned below the power head 10 after being erected, as shown in Figures 7 and 8. When the spare drill rod 6 is in the upright state, the power head 10 can also be raised to its original position. At this time, as shown in Figures 8 and 9, the power head 10 is lowered and connected to the spare drill rod 6 below it. After the power head 10 is connected to the spare drill rod 6 below it, the picking piece 40 can be loosened and the lifting assembly 4 can be returned to its original position. At the same time, as shown in Figure 10, the power head 10 continues to descend until the spare drill rod 6 connected below the power head 10 is moved to the top of the original drill rod 5. Then the bottom end of the spare drill rod 6 can be connected to the top of the original drill rod 5, and the power head 10 is started to drive the spare drill rod 6 and the original drill rod 5 to rotate simultaneously, so that the spare drill rod 6 is also drilled into the soil at the designed pile position.

[0094] The above process of moving the spare drill rod 6, rotating the spare drill rod 6, connecting the spare drill rod 6 and the power head 10, lowering the power head 10, connecting the spare drill rod 6 and drilling the spare drill rod 6 into the soil can be repeated. Multiple spare drill rods 6 can be connected and drilled in sequence, and finally a drilling tool formed by multiple drill rod connecting rods is drilled into the soil at the designed pile position of the bored pile. The drilling tool can meet the design length requirements of the bored pile and can be used for the construction of cast-in-place bored piles.

[0095] Among them, after the picking part 40 can grab the spare drill rod 6 at the loading position, in order to prevent the lifting assembly 4 and the moving assembly 3 from interfering with each other during the subsequent movement of the spare drill rod 6, as shown in Figures 4 and 5, the moving assembly 3 can be moved back to its original position in the opposite direction, and then the lifting assembly 4 can be started to rotate the lifting assembly 4 relative to the pile frame platform 2.

[0096] It should be noted that in the process of connecting multiple spare drill rods 6 in sequence, the horizontally distributed spare drill rods 6 on the pile frame platform 2 that have not yet moved to the loading position can continue to act as a counterweight to ensure the balance and stability of the gantry pile driver. At the same time, since each spare drill rod 6 will be drilled into the soil after the connection, the weight at the gantry 1 will not continue to increase as the connection operation proceeds. Even if the connection operation enters the later stage and there are no longer horizontal spare drill rods 6 distributed on the pile frame platform 2, the center of gravity of the gantry pile driver will not shift beyond the gantry 1, and the stability of the gantry pile driver can still be guaranteed.

[0097] It should also be noted that whether it is the connection process between the original drill rod 5 and the power head 10, the connection process between the spare drill rod 6 and the power head 10, or the connection process between two adjacent drill rods, manual connection or automatic connection can be adopted.

[0098] Among them, the automatic connection method can be implemented by using a joint assembly with an elastic pin. In some embodiments, the joint assembly can include a male joint and a female joint. One of the male joint and the female joint can be provided with an elastic pin, and the other can be provided with a slot. When the male joint and the female joint are docked, the elastic pin can be automatically inserted into the slot; when the elastic pin is compressed under the action of an external force, it can be withdrawn from the slot, and the male joint and the female joint can be separated from each other. Optionally, a female joint can be provided at the power head 10 and at the bottom end of each spare drill rod 6, and a male joint can be used at the top end of each drill rod of the female joint. When the spare drill rod 6 is placed horizontally on the moving assembly 3, the male joint of the spare drill rod 6 perpendicular to the plane where the gantry 1 is located can be set close to the gantry 1, and the female joint of the spare drill rod 6 can be set away from the gantry 1.

[0099] In addition, in order to improve the connection accuracy between the power head 10 and the spare drill rod 6, a positioning member 100 can be provided on the power head 10. The positioning member 100 can be used to abut against the circumferential side wall of the spare drill rod 6 when the spare drill rod 6 is erected under the power head 10 to limit the spare drill rod 6, so that the spare drill rod 6 is stably located under the power head 10.

[0100] Compared to related art, the gantry pile driver provided by some embodiments of the present disclosure utilizes a method of horizontally placing multiple drill rods on a moving assembly 3 that moves in an orderly manner, and using a lifting assembly 4 to sequentially pick up and lift each drill rod point by point. This allows multiple drill rods placed horizontally at different workstations to be sequentially delivered to the same location within the portal frame 1 (below the power head 10) using a single stroke of the lifting assembly 4. This allows the drill rod transport, rod connection, and drilling process to proceed seamlessly and orderly. Furthermore, by horizontally distributing multiple drill rods on the moving assembly 3, the gantry pile driver can be counterweighted to ensure stability. During the rod connection process, the post-drilling process and the horizontally distributed drill rods that have not yet been connected can be utilized to ensure that the center of gravity of the gantry pile driver does not deviate excessively toward the portal frame 1, thereby maintaining the stability of the gantry pile driver.

[0101] As can be seen, the gantry pile driver provided by some embodiments of the present disclosure can achieve orderly horizontal placement of spare drill rods 6, thereby allowing the spare drill rods 6 to be safely, stably, and reliably positioned on the gantry pile driver, without causing the center of gravity of the gantry pile driver to shift and overturn. At the same time, because the moving assembly 3 can be moved orderly along a simple route on the pile frame platform 2, each spare drill rod 6 can be automatically moved to the loading position and aligned with the pickup member 40 of the lifting assembly 4. Then, through the rotation of the lifting assembly 4, the spare drill rod 6 can be switched from a horizontal state to an upright state and positioned below the power head 10. Therefore, the gantry pile driver provided by some embodiments of the present disclosure can also complete the work of removing, transporting, and connecting drill rods through three simple continuous actions: orderly horizontal placement of drill rods, horizontal movement of drill rods, and rotation of drill rods, thereby overcoming the problems of poor stability and unsmooth connection of pile drivers in related technologies.

[0102] In some embodiments of the present disclosure, a vertical force mechanism for driving the power head 10 upward or downward may be mounted on the mast 1. The vertical force mechanism may employ a telescopic drive device such as a pneumatic cylinder or an oil cylinder. It should be noted that the structure of the vertical force mechanism is not limited and may employ any device capable of driving the power head 10 upward or downward. For example, the vertical force mechanism may employ a chain device or a winch device.

[0103] As shown in Figure 1, the gantry 1 in the gantry pile driver provided in some embodiments of the present disclosure may adopt a gantry structure, and the gantry 1 may be composed of two parallel columns and a crossbeam perpendicularly connected between the two columns. The plane where the gantry 1 is located is the plane where the two columns and the crossbeam are located.

[0104] Optionally, each upright of the mast 1 can be formed by a sliding connection between a fixed rod 11 and a lifting rod 12, and the power head 10 and the lifting rod 12 can be fixedly connected. A vertical force mechanism can be mounted on the mast 1, but the output end of the vertical force mechanism can be connected to the power head 10. The vertical force mechanism can be used to drive the power head 10 up or down, and the lifting rod 12 can be driven by the power head 10 to slide vertically on the fixed rod 11. In this case, the fixed rod 11 and the lifting rod 12 can form a slide rail structure, effectively improving the lifting stability of the power head 10 on the mast 1.

[0105] In some embodiments of the present disclosure, a travel assembly 7 may be mounted on the bottom of the pile frame platform 2 to facilitate movement of the gantry pile driver. Optionally, the travel assembly 7 in some embodiments of the present disclosure may be a crawler-type travel mechanism or a walking-type travel mechanism. To enhance the support strength of the pile frame platform 2 in the gantry pile driver, the pile frame platform 2 in some embodiments of the present disclosure may include a housing and a support structure mounted within the housing. The support structure may be formed by connecting a plurality of load-bearing rods.

[0106] As shown in Figures 1, 11, 12 and 21, the moving assembly 3 may include multiple sliding mechanisms 30, and the multiple sliding mechanisms 30 may be distributed at intervals along a direction perpendicular to the plane where the gantry 1 is located. The multiple sliding mechanisms 30 can be used to support multiple drill rods and drive the multiple drill rods to move; along the direction perpendicular to the plane where the gantry 1 is located, the picking parts 40 at the loading position and the multiple sliding mechanisms 30 may be staggered.

[0107] As shown in Figures 11, 12, 13 and 14, the sliding mechanism 30 can be moved on the pile frame platform 2 in a direction parallel to the plane of the portal frame 1 under the drive of an external force. At this time, by adjusting the moving stroke of the sliding mechanism 30, the sliding mechanism 30 can accurately transport the spare drill rod 6 to be connected to the loading position.

[0108] It should be noted that when there are multiple sliding mechanisms 30 and each sliding mechanism 30 supports multiple spare drill rods 6, each spare drill rod 6 can be accurately moved to the loading position by adjusting the moving stroke of the sliding mechanism 30.

[0109] It should also be noted that the picking piece 40 and multiple sliding mechanisms 30 at the loading position are staggered in a direction perpendicular to the plane of the gantry 1, which can effectively prevent the picking piece 40 and the sliding mechanism 30 from obstructing each other and making it difficult to move the spare drill rod 6 into place.

[0110] Furthermore, to prevent the spare drill rod 6 on the sliding mechanism 30 moving to the loading position from interfering with the pick-up member 40, as shown in FIG11 , the top of the pick-up member 40 in the open state can be lower than the spare drill rod 6. As shown in FIG13 , after the sliding mechanism 30 drives the spare drill rod 6 to the loading position, the pick-up member 40 can be closed again to grab the spare drill rod 6 located above it.

[0111] As shown in Figures 13 and 15, the sliding mechanism 30 can be a telescopic structure, and the sliding mechanism 30 can drive the drill rod it supports to rise and fall during the process of extension and retraction. Specifically, the sliding mechanism 30 can be in an extended state during the process of supporting and transporting the spare drill rod 6. After the sliding mechanism 30 transports the spare drill rod 6 to the loading position and the pick-up member 40 grabs the spare drill rod 6, as shown in Figures 15 and 16, the sliding mechanism 30 can be shortened and lowered. At this time, a gap is generated between the sliding mechanism 30 and the spare drill rod 6 grabbed by the pick-up member 40, making it easier for the sliding mechanism 30 to slide back to its original position. It can be seen that when the sliding mechanism 30 is a telescopic structure, it is convenient for the sliding mechanism 30 to return to its original position after moving the spare drill rod 6 into place.

[0112] As shown in Figures 17 and 18, when the sliding mechanism 30 moves in the opposite direction to return to the original position, the sliding mechanism 30 can still remain in the shortened state. After the sliding mechanism 30 moves to the original position, as shown in Figures 19 and 20, the sliding mechanism 30 needs to be extended to wait for the transportation of the next spare drill rod 6.

[0113] As shown in Figures 1 and 21, a plurality of guide rails 20 can be provided on the pile frame platform 2. The plurality of guide rails 20 can be distributed at intervals in a direction perpendicular to the plane where the gantry 1 is located, and each guide rail 20 can extend in a direction parallel to the plane where the gantry 1 is located; a plurality of sliding mechanisms 30 can be slidably connected to the plurality of guide rails 20 in a one-to-one correspondence.

[0114] The guide rail 20 can not only limit the moving direction of the sliding mechanism 30 , but also reduce the friction between the sliding mechanism 30 and the pile frame platform 2 , thereby improving the moving smoothness of the sliding mechanism 30 .

[0115] Optionally, the number of movable assemblies 3 can be an even number, and an even number of movable assemblies 3 can be divided into two groups, and the two groups of movable assemblies 3 can be symmetrically distributed on both sides of the loading position. When the number of movable assemblies 3 is an even number and the distribution is symmetrical, not only can the distribution of the movable assemblies 3 be more orderly and uniform, but the distribution of the spare drill rods 6 can also be more orderly and uniform, thereby effectively improving the counterweight balance of the gantry pile driver.

[0116] As shown in Figure 1, each sliding mechanism 30 can be provided with a first clamping position 300 and a second clamping position 301 distributed at intervals. The first clamping positions 300 of multiple sliding mechanisms 30 can be distributed on the same straight line to support the same drill rod, and the second clamping positions 301 of multiple sliding mechanisms 30 can be distributed on the same straight line to support the same drill rod.

[0117] The first clamping position 300 on the sliding mechanisms 30 can be used to support one spare drill rod 6, and the second clamping position 301 on the sliding mechanisms 30 can be used to support another spare drill rod 6. At this time, each moving component 3 can support two drill rods.

[0118] As shown in Figure 1, the sliding mechanism 30 can be a slider with a pulley 302 at the bottom, the pulley 302 can be slidably connected to the guide rail 20, and the slider can be used to support the spare drill rod 6. Optionally, the first clamping position 300 and the second clamping position 301 can both be a clamping groove provided on the top of the sliding mechanism 30.

[0119] If the sliding mechanism 30 is a telescopic structure at this time, the slider can be a cover with an opening at the bottom, and the sliding mechanism 30 also includes a bottom plate and a scissor mechanism 303. The bottom plate can be set at the bottom of the slider, the pulley 302 can be installed on the bottom surface of the bottom plate, and the scissor mechanism 303 can be connected between the top surface of the bottom plate and the inner wall of the slider. The scissor mechanism 303 can be formed by a plurality of connecting rods hinged together, which can be extended or shortened, thereby driving the hollow slider to rise or fall relative to the bottom plate.

[0120] Optionally, when the first and second latch positions 300 and 301 are both latch slots, the first and second latch positions 300 and 301 can be located at the same height. In this case, the first and second latch positions 300 and 301 can be spaced apart on the top of the sliding mechanism 30 along the moving direction of the sliding mechanism 30 .

[0121] Alternatively, as shown in FIG22 , the sliding mechanism 30 may be composed of two adjacent sliding brackets 304 . In this case, each guide rail 20 may include two branch rails arranged in parallel, and the two sliding brackets 304 may be slidably connected to the two branch rails in a one-to-one correspondence.

[0122] As shown in FIG22 , the bottom of the sliding bracket 304 may be provided with a perforation through which the sliding bracket 304 can be slidably connected to the branch track of the guide rail 20. The first latch 300 and the second latch 301 may both be made of a support plate. In this case, the first latch 300 may be fixedly connected to one side of one sliding bracket 304 in the sliding mechanism 30, and the second latch 301 may be fixedly connected to one side of the other sliding bracket 304 in the sliding mechanism 30.

[0123] To prevent interference between the first locking position 300 and the second locking position 301, as shown in FIG22 , the vertical distance between the first locking position 300 and the pile frame platform 2 may not be equal to the vertical distance between the second locking position 301 and the pile frame platform 2. Alternatively, the vertical distance between the first locking position 300 and the pile frame platform 2 may be greater than the vertical distance between the second locking position 301 and the pile frame platform 2. In this case, the height above the ground of the spare drill rod 6 supported by the first locking position 300 of the multiple sliding mechanisms 30 may be greater than the height above the ground of the spare drill rod 6 supported by the second locking position 301 of the multiple sliding mechanisms 30.

[0124] When both the first and second locking positions 300, 301 utilize support plates, the sliding brackets 304 in the plurality of sliding mechanisms 30 in the moving assembly 3 can be moved sequentially in batches. In some embodiments, as shown in Figures 23 and 24, an external force can be first used to push only the sliding bracket 304 in the sliding mechanism 30 with the first locking position 300 in a direction parallel to the plane of the gantry 1 until the spare drill rod 6 in the first locking position 300 is moved to the loading position. The picking member 40 is then activated to grab the spare drill rod 6 at the loading position, and then all the sliding brackets 304 in the first locking position 300 are moved back to their original positions.

[0125] After the sliding bracket 304 with the first clamping position 300 has been moved back to its original position, the spare drill rod 6 on the second clamping position 301 of the sliding bracket 304 can be moved to the loading position. It should be noted that since the multiple sliding mechanisms 30 in the moving assembly 3 are spaced apart in a direction perpendicular to the plane where the gantry 1 is located, when the first clamping position 300 of the sliding bracket 304 no longer supports the spare drill rod 6, the movement process of the sliding bracket 304 with the second clamping position 301 is no longer hindered by the spare drill rod 6 on the first clamping position 300. At this time, external force can be used to push only the sliding bracket 304 with the second clamping position 301 in the sliding mechanism 30 to move in a direction parallel to the plane where the gantry 1 is located until the spare drill rod 6 on the second clamping position 301 is moved to the loading position.

[0126] Furthermore, when both the first and second latching positions 300 and 301 utilize support plates and the sliding mechanism 30 is a telescopic structure, the sliding bracket 304 may be a telescopic bracket. In some embodiments, the sliding bracket 304 may include a horizontal rod having a perforation and a vertical rod perpendicularly connected to the horizontal rod. A sliding rod may be slidably connected to the vertical rod. The first and second latching positions 300 and 301 may be located on one side of the sliding rod. In this case, the sliding bracket 304 may be extended or retracted by sliding the sliding rod on the vertical rod, thereby driving the first and second latching positions 300 and 301 to rise or fall.

[0127] As shown in Figures 24 and 25, when the sliding bracket 304 with the first clamping position 300 transports the spare drill rod 6 it supports to the loading position and the picking part 40 grabs the spare drill rod 6, the sliding rod can be driven to slide downward on the vertical rod, thereby driving the first clamping position 300 to descend, so that there is a gap between the first clamping position 300 and the spare drill rod 6, and then it is easy to move the sliding bracket 304 in the opposite direction to make the sliding bracket 304 return to its original position.

[0128] In some embodiments of the present disclosure, the pile frame platform 2 may further be provided with a mobile drive mechanism, which can be used to apply external force to the mobile assembly 3 to propel the mobile assembly 3 to move on the pile frame platform 2. Optionally, the mobile drive mechanism can be a telescopic drive device such as a pneumatic cylinder or an oil cylinder, or a conveying device composed of a motor and a conveyor chain.

[0129] It should be noted that the sliding mechanism 30 in the moving assembly 3 provided in some embodiments of the present disclosure is not limited to having only the first and second latching positions 300, 301. A third, fourth, or other latching positions may be provided as needed. Furthermore, the structural form of the sliding mechanism 30 is not limited to the two aforementioned structures. Any structure capable of transporting the spare drill rod 6 to the loading position in an orderly manner along a simple route may be employed.

[0130] As shown in Figures 5 and 6, the lifting assembly 4 may include a mechanical arm 41 and a jacking drive mechanism, and the picking member 40 may be a mechanical clamp; the mechanical arm 41 may include a hinged end and a suspended end, the hinged end of the mechanical arm 41 may be hinged to the pile frame platform 2, and the suspended end of the mechanical arm 41 may be suspended in the air; the mechanical clamp may be installed on the mechanical arm 41, and the output end of the jacking drive mechanism may be connected to the mechanical arm 41, and the jacking drive mechanism may be used to drive the mechanical arm 41 to rotate relative to the pile frame platform 2 so that the mechanical arm 41 switches between a horizontal state and an upright state.

[0131] The lifting drive mechanism may be a telescopic drive device such as an air cylinder or an oil cylinder. The opening and closing of the mechanical gripper may be achieved by electric or pneumatic means. Correspondingly, the mechanical gripper may be an electric gripper or a pneumatic gripper.

[0132] Some embodiments of the present disclosure provide that the robotic arm 41 in the lifting assembly 4 can be used to switch between a horizontal state and a vertical state under the drive of a jacking drive mechanism, thereby driving the spare drill rod 6 to switch between a horizontal state and a vertical state. Since the spare drill rod 6 can be accurately located below the power head 10 when it is rotated to the vertical state, the robotic arm 41 can only rotate within the range of 0-90 degrees.

[0133] To improve the flexibility of the use of the robotic arm 41 , in some embodiments of the present disclosure, the length of the robotic arm 41 is shorter than the length of the spare drill rod 6 . In this case, the picking piece 40 can be installed at the suspended end of the robotic arm 41 .

[0134] As shown in Figures 5 and 6, the hinged end of the robotic arm 41 can be located between the gantry 1 and the loading position, and the robotic clamp can be installed on the arm surface of the robotic arm 41 facing away from the pile frame platform 2, or, as shown in Figures 31 to 34, the robotic clamp can be installed on the arm surface of the robotic arm 41 facing the pile frame platform 2, and a turntable mechanism 21 can be installed on the pile frame platform 2, and the hinged end of the robotic arm 41 can be hinged to the turntable mechanism 21, and the turntable mechanism 21 can be used to drive the robotic arm 41 to rotate with the center axis of the robotic arm 41 as the axis of rotation.

[0135] When the hinged end of the robotic arm 41 is located between the gantry 1 and the loading station, in order to ensure that the spare drill rod 6 is accurately positioned below the power head 10 when it is rotated to the upright position, it is necessary to ensure that after the mechanical gripper on the robotic arm 41 grabs the spare drill rod 6, the spare drill rod 6 is positioned on the side of the robotic arm 41 close to the gantry 1. Therefore, the mechanical gripper can be directly mounted on the arm surface of the robotic arm 41 facing away from the pile frame platform 2. Alternatively, the mechanical gripper can be mounted on the arm surface of the robotic arm 41 facing the pile frame platform 2 and a turntable mechanism 21 can be added to enable the robotic arm 41 to rotate after being erected, thereby driving the spare drill rod 6 to turn.

[0136] In some embodiments, for a method of directly installing the mechanical gripper on the arm surface of the mechanical arm 41 facing away from the pile frame platform 2, as shown in Figures 3, 5 and 6, at the loading position, the mechanical gripper will grab the spare drill rod 6 from bottom to top, and the grabbed spare drill rod 6 will be located above the mechanical arm 41.

[0137] Regarding the method of installing the mechanical gripper on the arm surface of the mechanical arm 41 facing the pile frame platform 2, as shown in Figures 31 and 32, at the loading position, the mechanical gripper will grab the spare drill rod 6 from top to bottom, and the grabbed spare drill rod 6 will be located below the mechanical arm 41. When the mechanical arm 41 drives the spare drill rod 6 to rotate to an upright state, as shown in Figure 33, the spare drill rod 6 will be located on the side of the mechanical arm 41 facing away from the gantry 1. At this time, in order to make the spare drill rod 6 be located on the side of the mechanical arm 41 facing the gantry 1 and below the power head 10, it is necessary to use the turntable mechanism 21 to drive the mechanical arm 41 to rotate 180 degrees and move the spare drill rod 6 to below the power head 10.

[0138] The turntable mechanism 21 may adopt a rotation drive device including a motor.

[0139] In some embodiments of the present disclosure, the position of the robotic arm 41 can be adjusted so that after the mechanical gripper grabs the spare drill rod 6, the spare drill rod 6 can be located on the side of the robotic arm 41 close to the gantry 1. In some embodiments, as shown in Figures 26-30, the side of the pile frame platform 2 where the gantry 1 is provided can be connected to the extension frame 22, the hinged end of the robotic arm 41 can be hinged to the extension frame 22, and the robotic arm 41 can pass through the gantry 1 during its rotation relative to the pile frame platform 2 and then stand upright on the side of the gantry 1 facing away from the loading position; the mechanical gripper can be installed on the arm surface of the robotic arm 41 facing the pile frame platform 2.

[0140] As shown in Figure 26 , at the loading position, the mechanical gripper will grasp the spare drill rod 6 from top to bottom, and the grasped spare drill rod 6 will be located below the mechanical arm 41. When the mechanical arm 41 drives the spare drill rod 6 to rotate to the upright position, because the hinged end of the mechanical arm 41 is hinged to the extension frame 22, the mechanical arm 41 will drive the spare drill rod 6 through the gantry 1, as shown in Figure 27 . At this time, the spare drill rod 6 is located on the side of the mechanical arm 41 facing the gantry 1 and below the power head 10.

[0141] In addition, to prevent the mechanical arm 41 from obstructing the process of connecting the spare drill rod 6, as shown in Figures 28 and 29, the mechanical arm 41 must remain upright during the process of connecting the rod and the process of the power head 10 rising after connecting the rod. When it is time to pick up the next spare drill rod 6, as shown in Figure 30, the mechanical arm 41 is rotated to a horizontal position.

[0142] It should be noted that, in order to prevent the extension frame 22 from obstructing the connecting rod and drilling process of the drill rod, the extension frame 22 needs to be provided with a through hole capable of passing the power head 10 and the drill rod at a position opposite to the power head 10 .

[0143] To further improve the balance of the gantry pile driver, the gantry pile driver of some embodiments of the present disclosure further includes a counterweight structure, which can be installed on the side of the pile frame platform 2 opposite to the gantry 1 to prevent the center of gravity of the pile driver from shifting toward the gantry 1. The counterweight structure of some embodiments of the present disclosure can be a self-adjusting counterweight assembly 8. Optionally, the gantry pile driver can further include a monitoring system and a control system 9. The self-adjusting counterweight assembly 8 can be installed on the side of the pile frame platform 2 away from the gantry 1, and the self-adjusting counterweight assembly 8 can include a movable portion that can move in a direction perpendicular to the plane of the gantry 1. Both the self-adjusting counterweight assembly 8 and the monitoring system can be connected to the control system 9. The monitoring system can be used to monitor weight changes at the gantry 1 of the gantry pile driver. The control system 9 can be used to calculate the amount of movement of the movable portion based on the weight changes monitored by the monitoring system, and can drive the movable portion to move in a direction perpendicular to the plane of the gantry 1 according to the amount of movement.

[0144] The self-adjusting counterweight assembly 8 can adopt a telescopic structure. In this case, the moving part can be the telescopic end of the self-adjusting counterweight assembly 8. The monitoring system can be used to sense the weight change at the gantry 1 of the gantry pile driver. The control system 9 can control the telescopic amount of the self-adjusting counterweight assembly 8 according to the monitoring results of the monitoring system, so that the self-adjusting counterweight assembly 8 automatically extends or shortens according to the weight change at the gantry 1 to adjust the torque of the pile frame platform 2 away from the gantry 1 side, thereby changing the center of gravity position of the gantry pile driver and maintaining the balance of the gantry pile driver.

[0145] Optionally, the self-adjusting counterweight assembly 8 can be implemented as an oil cylinder. In practical applications, the self-adjusting counterweight assembly 8 can also be implemented as a sliding block slidably connected to the pile frame platform 2. The monitoring system can be composed of a weight sensor, and the control system 9 can be implemented as a programmable logic controller or a single-chip microcomputer. The control system 9 can also be connected to the mobile assembly 3. In this case, the control system 9 can control the mobile assembly 3 to move along a predetermined path, eliminating the need for a cab for the gantry pile driver.

[0146] In summary, the gantry pile driver provided by some embodiments of the present disclosure can place the spare drill rods 6 in parallel on the moving assembly 3, and then orderly move the spare drill rods 6 horizontally to transport multiple spare drill rods 6 to the loading position in succession, and then rely on the rotation process of the lifting assembly 4 to successively and orderly send the multiple spare drill rods 6 to the bottom of the power head 10 in the portal 1 in a simple route to facilitate rod connection. The gantry pile driver can complete the process of grabbing and connecting the drill rods through simple actions, and the connecting rods can not only meet the construction requirements of ultra-long piles, but also the height of the portal 1 does not need to be set too high. Therefore, the gantry pile driver provided by some embodiments of the present disclosure can horizontally place and orderly combine the drill rods under the premise of using a low portal frame 1, and automatically, efficiently and safely perform the connecting rod operation to realize the construction of cast-in-place piles of various pile lengths in spaces of different heights (including low spaces such as tunnels).

[0147] It can be seen that the gantry pile driver provided by some embodiments of the present disclosure breaks the traditional design concept that the column height and drill tool length of the current mainstream heavy pile drivers must meet the designed pile length, and solves the problem that the vertical pre-fixed spare heavy drill tools often cause the center of gravity of the pile driver to shift, resulting in excessive weight at the front end of the pile driver. The gantry pile driver provided by some embodiments of the present disclosure is a disruptive technology to the pile drivers in the related art, and can achieve the lowering of the gantry 1, the horizontal placement of the drill rod and the automatic rod connection. It is a high-efficiency, energy-saving, safe, highly automated and low-cost pile driving machine.

[0148] It should also be noted that in the prior art, when heavy-duty drill bits are pre-fixed vertically on one side of the upright column of the gantry 1, counterweights must be added to ensure the pile driver's center of gravity is balanced. Consequently, when driving a 70-meter pile, the weight of the pile driver often increases from 150 tons to over 300 tons. This not only increases construction costs, but also requires extensive steel plate laying on the construction site to ensure pile safety, further increasing costs. However, the gantry pile drivers provided by some embodiments of the present disclosure, by laying the drill rod horizontally, can eliminate the drilling depth limitations imposed by the length of a single drill rod and eliminate the need for a large amount of counterweights to ensure the pile driver's center of gravity is balanced. For this reason alone, the gantry pile drivers provided by some embodiments of the present disclosure can be 30-40% lighter than those of the prior art, effectively reducing manufacturing costs. Furthermore, by utilizing a vertical force-adding mechanism on the gantry 1 that cooperates with the power head 10, the gantry pile drivers provided by some embodiments of the present disclosure can squeeze the soil during the drill rod's lowering and rotary excavate the pile hole, thus achieving construction without soil extraction and achieving energy conservation and emission reduction.

[0149] It should also be noted that, compared with CN202688997U, the gantry pile driver provided in some embodiments of the present disclosure proposes a specific technical solution for lowering the height and center of gravity of the gantry 1 and increasing the length of the construction pile.

[0150] Compared to the technical solution of CN208950504U which can only double the piling depth and increase the risk of unstable center of gravity of the pile driver, the gantry pile driver provided by some embodiments of the present disclosure can achieve a higher piling depth without increasing the height of the pile driver and enhancing the stability of the pile driver (the gantry pile driver provided by some embodiments of the present disclosure does not need to consider the unstable center of gravity caused by the upright drill rod, and the number or length of the spare drill rod 6 can be increased to increase the piling depth).

[0151] Compared with CN203851446U, the gantry pile driver provided in some embodiments of the present disclosure uses a vertical force-adding mechanism and a power head 10 on the gantry 1, as well as a joint assembly with an elastic pin, so that the gantry pile driver also has complex functions that cannot be imagined in the field of agricultural technology, such as rotating drilling tools, lowering drilling tools, lifting drilling tools, and automatic rod connection. In addition, the gantry pile driver provided in some embodiments of the present disclosure uses a gantry 1 instead of the single-column column of a traditional pile driver, so that the spare drill rod 6 can be directly moved into the gantry 1 or through the gantry 1 without having to take a complicated route around the single-column column.

[0152] Compared with CN209556966U, the gantry pile driver provided in some embodiments of the present disclosure can first grab the drill rod through the picking-up member 40 and then withdraw the moving assembly 3, without causing the drill rod to fall freely during the entire process. Moreover, during operation, a program can be pre-programmed on the control system 9 of the gantry pile driver to automatically transport multiple drill rods to the loading position in sequence and enable the picking-up member 40 to automatically pick up multiple drill rods in sequence, without the need for manpower or other auxiliary machinery to transport the drill rods.

[0153] Compared with CN110939132A, the self-adjusting counterweight assembly 8 of the gantry pile driver provided in some embodiments of the present disclosure can cooperate with the control system 9 and the monitoring system to have the characteristic of rapid adjustment. The gantry pile driver provided in some embodiments of the present disclosure adjusts the horizontal center of gravity position by changing the torque, which is more in line with the requirements of the gantry pile driver provided in some embodiments of the present disclosure.

[0154] The pile-driving machines disclosed in CN216381270U, ​​CN105756060A, and CN107023267B, however, are limited by their traditional single-column structures, requiring the drill rod to be grasped and moved around the single column. This results in a complex mechanism within the pile-driving machine, making it difficult to simplify. While placing the spare drill rod 6 vertically facilitates drill rod transportation and docking, it can lead to pile foundation instability. In contrast, the gantry pile driver provided by some embodiments of the present disclosure utilizes a horizontal placement of the spare drill rod 6. Combined with an improved overall machine structure, this allows for smooth drill rod grasping and movement while utilizing a low-profile gantry 1. Compared to pile-driving machines that place drill rods vertically, the gantry pile driver provided by some embodiments of the present disclosure is safer and more stable. Furthermore, by placing the drill rod horizontally, some embodiments of the present disclosure increase the contact area between the drill rod and the pile frame platform 2, thereby converting the point load during vertical placement into a surface load with a lower pressure when placed horizontally. This effectively reduces the strength requirements of the pile driver, thereby lowering the manufacturing cost of the pile driver.

[0155] As shown in FIG35 , some embodiments of the present disclosure further provide a bored pile construction method, which can apply the above-mentioned gantry pile driver and may include:

[0156] Step S1: Start the moving assembly 3 to transport one of the drill rods on the moving assembly 3 to the loading position;

[0157] Step S2: Start the lifting assembly 4 to make the pick-up member 40 grab the drill rod at the loading position, and after the moving assembly 3 moves away from the loading position, rotate the lifting assembly 4 to drive the drill rod grabbed by the pick-up member 40 to switch from a horizontal state to a vertical state and move it to under the power head 10;

[0158] Step S3: Connecting the top end of the drill rod grasped by the pickup member 40 to the power head 10, and then releasing the grasped drill rod by the pickup member 40;

[0159] Step S4: Drive the power head 10 downward, move the drill rod connected to the bottom of the power head 10 to the top of the drill rod buried at the designed pile position of the cast-in-place pile, and then connect the bottom end of the drill rod connected to the bottom of the power head 10 to the top end of the buried drill rod:

[0160] Step S5: Continue to drive the power head 10 downward and start the power head 10 so that the drill rod connected below the power head 10 rotates and drills into the soil at the designed pile position of the cast-in-place pile;

[0161] Step S6: Separate the power head 10 from the drill rod connected thereto, and then drive the power head 10 upward;

[0162] Step S7: Repeat steps S1 to S6 to sequentially connect the multiple drill rods on the mobile assembly 3 and drill them into the soil at the designed pile position of the cast-in-place pile.

[0163] Steps S1-S7 in the cast-in-place pile construction method provided in some embodiments of the present disclosure are all processes for connecting the drill rods placed horizontally on the pile frame platform 2, that is, the processes for connecting the aforementioned spare drill rod 6. The original drill rod 5 with the drill bit is usually directly connected to the bottom of the power head 10 to be drilled. Therefore, the cast-in-place pile construction method provided in some embodiments of the present disclosure may also include steps S01 and S02 before step S1:

[0164] Step S01: moving the gantry pile driver to the bored pile construction area, and positioning the power head 10 on the gantry 1 of the gantry pile driver above the designed pile position of the bored pile;

[0165] Step S02: Connect a drill rod with a drill bit below the power head 10 on the gantry 1 of the gantry pile driver, lower the power head 10 and start the power head 10 to drive the drill rod with the drill bit to rotate and drill into the soil at the designed pile position of the cast-in-place pile.

[0166] The bored pile construction method provided by some embodiments of the present disclosure applies the above-mentioned gantry pile driver. Therefore, the bored pile construction method can also counterweight the pile driver by horizontally distributing multiple drill rods on the mobile assembly 3 to ensure the stability of the gantry pile driver. During the rod connection process, the process of drilling after connecting the rods and the horizontal distribution of the drill rods that have not yet been connected can also be used to continue to ensure that the center of gravity of the gantry pile driver does not deviate too much toward the gantry 1, thereby continuing to ensure the stability of the gantry pile driver.

[0167] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure. Industrial Applicability

[0168] In summary, a gantry pile driver is provided, which can automatically, highly and safely perform rod connection operations by horizontally placing and orderly combining drill rods to realize cast-in-place pile construction of various pile lengths in spaces at different heights. This breaks the traditional design concept that the column height and drill tool length of the current mainstream heavy pile drivers must meet the designed pile length, and solves the problem that the vertical pre-fixed spare heavy drill tools often cause the center of gravity of the pile driver to shift, resulting in excessive weight at the front end of the pile driver. The gantry pile driver is an efficient, energy-saving, safe, highly automated and low-cost pile driving machine.

[0169] Furthermore, it is understood that the gantry pile driver and cast-in-place pile construction method disclosed herein are reproducible and can be used in a variety of industrial applications. For example, the gantry pile driver and cast-in-place pile construction method disclosed herein can be used in the field of pile foundation construction technology.

Claims

1. A gantry pile driver, wherein: It comprises a gantry (1), a pile frame platform (2), a moving component (3) and a lifting component (4); The gantry (1) is erected on one side of the pile frame platform (2), and a lifting power head (10) is installed on the gantry (1), and the power head (10) can be detachably connected to one end of any drill rod moved below it; The pile frame platform (2) is provided with a material loading position at a position located on one side of the portal frame (1), and the projection of the central axis of the power head (10) on the pile frame platform (2) is located in the extension direction of the material loading position; The moving assembly (3) is provided on one or both sides of the material loading position, and a plurality of drill rods are horizontally distributed on the moving assembly (3), and each of the drill rods is perpendicular to the plane where the gantry (1) is located; the moving assembly (3) is used to move on a horizontal plane in a direction parallel to the plane where the gantry (1) is located, so as to transport the plurality of drill rods to the material loading position in sequence; The lifting assembly (4) comprises a picking member (40) for grabbing the drill rod at the upper material position. The lifting assembly (4) is used to rotate relative to the pile frame platform (2) so as to drive the drill rod grabbed by the picking member (40) to switch from a horizontal state to a vertical state and move to below the power head (10) during the rotation process.

2. The gantry pile driver according to claim 1, wherein: The moving assembly (3) comprises a plurality of sliding mechanisms (30), the plurality of sliding mechanisms (30) being distributed at intervals in a direction perpendicular to the plane where the gantry (1) is located, and the plurality of sliding mechanisms (30) being used to support the plurality of drill rods and drive the plurality of drill rods to move; Along a direction perpendicular to the plane where the door frame (1) is located, the picking member (40) at the material loading position and the plurality of sliding mechanisms (30) are distributed in an alternating manner.

3. The gantry pile driver according to claim 2, wherein: The sliding mechanism (30) is a telescopic structure, and the sliding mechanism (30) is used to drive the drill rod supported by it to rise and fall during the telescopic process.

4. The gantry pile driver according to claim 2 or 3, wherein: The pile frame platform (2) is provided with a plurality of guide rails (20), the plurality of guide rails (20) are spaced apart in a direction perpendicular to the plane where the portal frame (1) is located, and each of the guide rails (20) extends in a direction parallel to the plane where the portal frame (1) is located; The plurality of sliding mechanisms (30) are slidably connected to the plurality of guide rails (20) in a one-to-one correspondence.

5. The gantry pile driver according to any one of claims 2 to 4, wherein: Each of the sliding mechanisms (30) is provided with a first clamping position (300) and a second clamping position (301) which are distributed at intervals; the first clamping positions (300) of a plurality of the sliding mechanisms (30) are distributed on the same straight line for supporting a same drill rod; and the second clamping positions (301) of a plurality of the sliding mechanisms (30) are distributed on the same straight line for supporting a same drill rod.

6. The gantry pile driver according to any one of claims 1 to 5, wherein: The lifting assembly (4) comprises a mechanical arm (41) and a lifting drive mechanism, and the picking member (40) is a mechanical clamp; The mechanical arm (41) comprises an articulated end and a suspended end, the articulated end of the mechanical arm (41) is articulated to the pile frame platform (2), and the suspended end of the mechanical arm (41) is suspended in the air; The mechanical gripper is mounted on the mechanical arm (41), the output end of the jacking drive mechanism is connected to the mechanical arm (41), and the jacking drive mechanism is used to drive the mechanical arm (41) to rotate relative to the pile frame platform (2) so that the mechanical arm (41) switches between a horizontal state and an upright state.

7. The gantry pile driver according to claim 6, wherein: The hinged end of the mechanical arm (41) is located between the gantry (1) and the loading position, and the mechanical gripper is installed on the arm surface of the mechanical arm (41) facing away from the pile frame platform (2), or, The mechanical gripper is mounted on the arm surface of the mechanical arm (41) facing the pile frame platform (2), and a turntable mechanism (21) is mounted on the pile frame platform (2). The hinged end of the mechanical arm (41) is hinged on the turntable mechanism (21), and the turntable mechanism (21) is used to drive the mechanical arm (41) to rotate with the central axis of the mechanical arm (41) as the rotation axis.

8. The gantry pile driver according to claim 6 or 7, wherein: The side of the pile frame platform (2) on which the portal frame (1) is provided is connected to an extension frame (22), the hinged end of the mechanical arm (41) is hinged to the extension frame (22), and the mechanical arm (41) can pass through the portal frame (1) and stand upright on the side of the portal frame (1) facing away from the loading position during the process of rotating relative to the pile frame platform (2); The mechanical gripper is mounted on the arm surface of the mechanical arm (41) facing the pile frame platform (2).

9. The gantry pile driver according to any one of claims 1 to 8, wherein: Also included is a self-adjusting weight assembly (8), a monitoring system and a control system (9); The self-adjusting counterweight assembly (8) is installed on a side of the pile frame platform (2) away from the portal frame (1), and the self-adjusting counterweight assembly (8) comprises a moving part capable of moving in a direction perpendicular to the plane where the portal frame (1) is located; The self-adjusting counterweight assembly (8) and the monitoring system are both connected to the control system (9); the monitoring system is used to monitor the weight change at the gantry (1) of the gantry pile driver; the control system (9) is used to calculate the movement amount of the moving part according to the weight change monitored by the monitoring system, and drive the moving part to move in a direction perpendicular to the plane where the gantry (1) is located according to the movement amount.

10. The gantry pile driver according to any one of claims 1 to 9, wherein: The number of the moving components (3) is an even number, and the moving components (3) are divided into two groups and are symmetrically distributed on both sides of the loading position.

11. The gantry pile driver according to any one of claims 1 to 10, wherein: The power head (10) and the drill rod are connected via a joint assembly with an elastic pin and a slot.

12. The gantry pile driver according to any one of claims 1 to 11, wherein: The power head (10) is provided with a positioning member (100), and the positioning member (100) is configured to abut against a circumferential side wall of the drill rod when the drill rod is erected below the power head (10) to limit the position of the drill rod.

13. The gantry pile driver according to any one of claims 1 to 12, wherein: The door frame (1) is composed of two parallel columns and a crossbeam vertically connected between the two columns. The columns are formed by a fixed rod (11) and a lifting rod (12) in a sliding connection. The power head (10) is fixedly connected to the lifting rod (12).

14. A method for constructing a bored pile, using a gantry pile driver as claimed in any one of claims 1 to 13, wherein: include: S1: starting the moving assembly (3) to transport one of the drill rods on the moving assembly (3) to the loading position; S2: starting the lifting assembly (4) so ​​that the picking member (40) grabs the drill rod at the material loading position, and rotating the lifting assembly (4) after the moving assembly (3) moves away from the material loading position, so as to drive the drill rod grabbed by the picking member (40) to switch from a horizontal state to a vertical state and move it to below the power head (10); S3: connecting the top end of the drill rod grasped by the picking member (40) to the power head (10), and then causing the picking member (40) to release the grasped drill rod; S4: driving the power head (10) to descend, moving the drill rod connected below the power head (10) to the top of the drill rod buried at the designed pile position of the cast-in-place pile, and then connecting the bottom end of the drill rod connected below the power head (10) to the top of the buried drill rod: S5: Continue to drive the power head (10) downward and start the power head (10), so that the drill rod connected below the power head (10) rotates and drills into the soil at the designed pile position of the cast-in-place pile; S6: separating the power head (10) from the drill pipe connected thereto, and then driving the power head (10) to rise; S7: Repeat steps S1-S6 to sequentially connect the multiple drill rods on the mobile assembly (3) and drill them into the soil at the designed pile position of the cast-in-place pile.

15. The bored pile construction method according to claim 14, wherein: The following steps are also included before step S1: S01: moving the gantry pile driver to a bored pile construction area, and making the power head (10) on the gantry (1) of the gantry pile driver be located above the designed pile position of the bored pile; S02: Connecting the drill rod with the drill bit below the power head (10) on the gantry (1) of the gantry pile driver, lowering the power head (10) and starting the power head (10) to drive the drill rod with the drill bit to rotate and drill into the soil at the designed pile position of the bored pile.

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