A construction system and method for a diaphragm wall cast in situ

Abstract

The application relates to the technical field of building engineering, in particular to a construction system and a construction method for in-situ cast diaphragm wall. The system comprises a plurality of portal frames arranged around a foundation pit, each portal frame is provided with at least two groups of lifting mechanisms, each portal frame is correspondingly provided with a bed frame and a columnar mold frame, the lifting mechanisms drive the bed frame and the columnar mold frame to lift, the bed frame is used for binding a steel reinforcement cage, and the columnar mold frame is used for closing the steel reinforcement cage to form a closed cavity of a diaphragm wall to be cast; and a prestressed sinking assisting mechanism is used for driving the diaphragm wall to sink. The scheme provided by the application can realize in-situ binding and layered pouring of the diaphragm wall steel reinforcement structure, the wall body is driven to sink in layers by the prestressed sinking assisting mechanism, the traditional full-depth trenching construction mode is not needed, only a guide trench for positioning of a first layer needs to be excavated, the problems of difficult trenching and easy leakage of joints under special geological conditions can be solved, and the scheme has the advantages of reducing construction cost and waste mud slurry discharge.

Description

Technical Field

[0001] This application relates to the field of building engineering technology, and in particular to an in-situ cast-in-place diaphragm wall construction system and construction method. Background Technology

[0002] Diaphragm walls are a widely used retaining structure in deep foundation pit engineering. They are adaptable to various geological conditions, including sandy soil layers and gravel layers with a particle size of less than 50mm, and are widely used in the construction of basements, underground parking lots, deep foundation pits, and industrial deep pools. The current mainstream construction process for diaphragm walls adopts a sequential construction mode: trenching first, then cage placement, and finally pouring concrete. First, trenching equipment is used to excavate unit sections, and mud slurry is used to maintain the stability of the trench walls. Then, the prefabricated steel cage is hoisted into the trench as a whole, and finally, underwater concrete is poured to form a single wall segment. Multiple unit sections are constructed sequentially to form a continuous wall. Some improved processes attempt to use prefabricated wall segment splicing technology, where standardized wall segments are prefabricated in a factory and then hoisted into the trench for splicing to improve construction efficiency.

[0003] However, traditional techniques face significant challenges in practical applications: in soft silty soil layers, the high fluidity of the soil makes the trench walls extremely prone to instability and collapse; in alluvial layers containing boulders, hard obstacles cause frequent damage to trenching equipment, making it difficult to maintain the integrity of the trench walls; and ultra-hard rock strata make trenching operations almost impossible, severely limiting the applicability of the technique. Simultaneously, the joints formed by splicing unit trench sections become weak points in the structure. Under the influence of complex geology or construction deviations, adjacent wall sections are prone to misalignment, significantly increasing the risk of leakage at the joints and directly weakening the overall impermeability and structural safety of the wall. Furthermore, when the wall is only used as a temporary retaining structure, the combined investment of high rental costs for trenching equipment, mud recycling and treatment costs, and the hoisting of large steel cages far exceeds that of alternative solutions such as sheet piles or soil nailing walls, making it clearly uneconomical. In urban environments, the large amount of waste mud generated during the trenching stage contains suspended particles and chemical additives. Its transportation and disposal are not only costly but also easily cause soil and water pollution, violating the principles of green construction. The aforementioned problems collectively restrict the reliable application and sustainable development of traditional processes under special geological conditions. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this application provides an in-situ cast-in-place diaphragm wall construction system, which can realize in-situ binding and layered casting of diaphragm wall reinforcement structure. Combined with a prestressed sinking mechanism to drive the wall to sink layer by layer, it eliminates the need for traditional full-depth trenching construction methods. Only a guide trench for the first layer positioning needs to be excavated. This can solve the problems of difficult trenching and easy leakage at joints under special geological conditions, and also save the process of hoisting large steel cages. It has the advantages of improving construction efficiency and wall integrity, reducing construction costs and waste mud discharge.

[0005] The first aspect of this application provides an in-situ cast-in-place diaphragm wall construction system, including several sets of prestressed sinking mechanisms and several gantry frames connected end to end. The gantry frames are arranged around the foundation pit to be constructed. Each gantry frame is provided with at least two sets of lifting mechanisms at intervals along its own length direction. Each gantry frame is correspondingly equipped with a jig and a columnar formwork. The lifting mechanism is used to drive the jig frame to rise and fall during binding and to drive the column formwork frame to rise and fall during the pouring of the diaphragm wall. The frame is used for in-situ binding of the reinforcing steel skeleton. Each reinforcing steel skeleton is connected end to end along the perimeter of the foundation pit to form a continuous reinforcing steel structure. The continuous reinforcing steel structure is provided with a reserved channel for the steel strand to be threaded through. Each columnar formwork is used to close the two sides of the steel reinforcement skeleton along the width direction of the gantry frame, and adjacent columnar formworks are joined together to enclose the continuous steel reinforcement structure to form a closed cavity for the diaphragm wall to be poured. The prestressed sinking mechanism includes a push mechanism, steel strands, and anchor piles. The anchor piles are spaced apart below the guide groove along the construction axis of the diaphragm wall. One end of the steel strand is connected to the anchor pile, and the other end passes through a reserved channel of continuous steel reinforcement structure and is connected to the push mechanism. The push mechanism is located at the top of the diaphragm wall and is used to tension the steel strands and apply a downward reaction force to the diaphragm wall to cause the diaphragm wall to break through the soil and sink. The system is equipped with a fixed pulley assembly. After the first layer of steel reinforcement skeleton is tied and formed on the outside of the guide groove, it is hoisted into the guide groove by the lifting mechanism in conjunction with the fixed pulley assembly. The system is configured to continue subsequent layers of reinforcement binding, formwork closure, and pouring construction on the top surface of the already poured diaphragm wall.

[0006] In some embodiments, the gantry frame includes a truss, columns, and diagonal braces, with the truss mounted on top of the columns and the diagonal braces arranged at an angle, with both ends of the diagonal braces connected to the truss and the columns, respectively. The lifting mechanism includes a winch, the output end of which is wound with a steel cable, the end of which is provided with a shackle, and the jig and columnar mold frame are provided with multiple lifting lugs that are adapted to the shackles.

[0007] In some embodiments, the frame includes an inner frame, two outer frames, and several support members. The inner frame is used to connect to the output end of the lifting mechanism. The two outer frames are respectively disposed on both sides of the inner frame along the width direction of the gantry frame. The two ends of the support members are respectively hinged to the inner frame and the outer frame. The outer frame is provided with several snap-fit ​​components arranged in an array on its outer side. The snap-fit ​​components are used to receive and position the reinforcing bars to be tied. When the inner and outer frames are grounded, the outer frame unfolds to form the binding and positioning station for the steel reinforcement frame. When the lifting mechanism drives the inner frame to rise, the outer frame rotates downward around the hinge point and retracts under the action of gravity, so that the jig can be dislodged from the inside of the steel frame.

[0008] In some embodiments, the inner frame is provided with a limiting seat, which has a side surface parallel to the horizontal plane. When the support rotates to a horizontal state, the upper surface of the support fits against the side surface to limit the maximum angle of upward rotation of the outer frame. The bottom of the outer frame is equipped with casters. When the bottom surface of the casters is flush with the bottom surface of the inner frame, the support is in a horizontal state. The snap-fit ​​component includes a first snap-fit ​​component and a second snap-fit ​​component. The first snap-fit ​​component is equidistantly distributed on the outer frame along the length of the gantry frame and is used to position the longitudinal reinforcing bars. The second snap-fit ​​component is equidistantly distributed on the outer frame along the height of the gantry frame and is used to position the transverse reinforcing bars. The second card is tilted upwards at an angle of 10° to 30°.

[0009] In some embodiments, the columnar mold frame includes a drive assembly, a first axial member, a second axial member, a third axial member and a fourth axial member arranged sequentially along the circumference, and two sets of four-bar linkages located at both ends of the columnar mold frame in the axial direction. The two ends of the first axial member, the second axial member, the third axial member, and the fourth axial member are respectively connected to the hinge shafts of two sets of four-bar linkages; The first axial member is connected to the output end of the lifting mechanism. The first axial member and the third axial member are arranged radially opposite to each other. The second axial member and the fourth axial member are respectively hinged to the casting template. The driving component is used to drive the third axial member to move closer to or away from the central axis of the columnar mold frame, so as to drive the two sets of casting templates to move towards or away from each other.

[0010] In some embodiments, the first axial member, the second axial member, the third axial member, and the fourth axial member are all long strip-shaped rods; The four-bar linkage includes a first link, a second link, a third link, and a fourth link that are hinged end to end in sequence; the length of the first link is equal to the length of the fourth link, the length of the second link is equal to the length of the third link, and the length of the first link is greater than the length of the second link; when the second link and the third link are collinear, the distance between the two sets of casting templates reaches its maximum value.

[0011] In some embodiments, the drive component is a hydraulic jack, which is connected to a first axial member via a bracket, and the output end of the hydraulic jack is connected to a third axial member. The casting template includes a support frame and a panel laid inside the support frame. The top of the support frame is provided with a mounting seat. The mounting seat is provided with an assembly hole extending along the axial direction of the columnar template. The second axial member and the fourth axial member respectively pass through the assembly hole of the corresponding mounting seat. The columnar mold frame also includes a limiting member, one end of which is rotatably connected to the second axial member, and the other end is engaged with the fourth axial member.

[0012] In some embodiments, the reverse thrust mechanism includes a through-hole jack and a reaction frame, the steel strand is threaded through the through-hole jack, the through-hole jack is fixed to the top end face of the diaphragm wall by the reaction frame, and the through-hole jack pushes the diaphragm wall down when tensioning the steel strand.

[0013] In some implementations, an automatic spray curing device and a soil removal device are also included; The automatic sprinkler curing device includes a pipe rack, pipes, sprinkler heads, temperature and humidity sensors, and a controller. The pipe rack slides along the height direction with a slide rail and is connected to a gantry frame. The pipe rack is provided with several ropes at intervals. The ropes are wrapped around the gantry frame and tied to the gantry frame. The pipes are fixed on the pipe rack and are arranged around the foundation pit to be constructed. The pipes are provided with several sprinkler heads. The spray direction of the sprinkler heads is inclined downward at 45°. The excavation device includes a conveyor belt, and an installation frame is provided in the foundation pit. The conveyor belt is inclined through the installation frame, with the feed end of the conveyor belt located inside the foundation pit and the discharge end located outside the foundation pit. When the diaphragm wall is under maintenance, the spray head descends to one side of the diaphragm wall along with the pipe rack. The controller controls the spraying duration and spraying interval based on the humidity and temperature information from the temperature and humidity sensors.

[0014] A second aspect of this application provides a construction method based on the above-mentioned in-situ cast-in-place diaphragm wall construction system, comprising the following steps: S1. Several pile holes are constructed at intervals along the construction axis of the diaphragm wall. Steel strands are installed on the precast foundation pile reinforcement cage. The reinforcement cage is lowered into the pile hole and concrete is poured to form an anchor pile. One end of the steel strand is anchored inside the anchor pile, and the other end extends out of the ground by a predetermined length. S2. Construct soil removal equipment inside and outside the foundation pit. After the equipment is in place, assemble the gantry frame, lifting mechanism and automatic spray curing device. Hoist the formwork and column formwork to the corresponding working position of the gantry frame. Excavate the diaphragm wall guide trench and complete the trench wall support. S3. Tie a single section of steel reinforcement cage in situ on the formwork, and lower the steel reinforcement cage into the guide groove through the lifting mechanism. Connect each section of steel reinforcement cage in sequence along the perimeter of the foundation pit to form a continuous steel reinforcement structure. Drive the columnar formwork to close to seal the two sides of the steel reinforcement structure, forming a closed cavity. Pour the concrete for the ground diaphragm wall of the current layer to a height of 2m. S4. After the current layer of diaphragm wall has been cured to the design strength, the excavator inside the foundation pit will excavate the soil layer by layer from the side away from the soil removal device towards the soil removal device. The soil that is far away from the soil removal device will be transferred to the feeding end of the soil removal device by the transfer equipment. The soil removal device will then transport the soil to the outside of the foundation pit and complete the soil removal by the external transport vehicle. S5. After the excavation depth in the foundation pit reaches 1m, start the reverse thrust mechanism to tension the steel strands and apply a downward prestressed reaction force to the diaphragm wall of the current layer, driving the wall to sink as a whole by 1m; after excavating to a depth of 1m, tension the steel strands again to drive the wall to sink a second time by 1m, stop the tensioning operation, and complete the construction work of the current layer. S6. On the top surface of the diaphragm wall that has been formed in the previous layer, repeat the steel reinforcement binding, formwork pouring, layered excavation and sinking operation of steps S3 to S5 until the diaphragm wall sinks to the design elevation. Finally, the foundation pit is excavated to the design depth.

[0015] Compared with the prior art, the in-situ cast-in-place diaphragm wall construction system and construction method provided in this application have the following advantages: (1) The gantry frame provides a span operation space. Combined with the in-situ binding frame and the openable column formwork, the steel reinforcement skeleton can be tied in situ and layered pouring can be extended. Combined with the prestressed sinking mechanism composed of anchor piles, steel strands and reverse thrust mechanism, the wall can be driven to sink simultaneously during the excavation of the foundation pit. There is no need to use the traditional full-depth trenching construction method. Only the guide trench for the first floor positioning needs to be excavated. This solves the problems of trenching difficulty under special geological conditions and easy leakage of wall joints in traditional process. It also saves the large steel cage hoisting and long-distance transportation process.

[0016] (2) The hinged structure of the frame can be raised and lowered, and unfolded to form a binding and positioning position for the steel reinforcement skeleton. It can be removed from the inside of the steel reinforcement skeleton without interference without disassembling the frame. It can save the disassembly and reassembly process of the traditional frame, and can be adapted to the construction rhythm of continuous stacking. It has the advantage of improving the construction efficiency of layered jointing.

[0017] (3) The column formwork can be opened and closed by a four-bar linkage. When the formwork is closed, it can fit the side of the steel reinforcement skeleton to form a closed pouring cavity. When the formwork is opened, the horizontal dimension of the column formwork is expanded, and demolding can be achieved without disassembling and assembling the formwork piece by piece. It can be adapted to the continuous operation requirements of in-situ stacked pouring and has the advantage of improving the formwork support and demolding efficiency of layered pouring.

[0018] (4) By using the structure of the through-hole jack and the reaction frame, the tension of the pre-embedded steel strand can be used to directly apply a uniform downward reaction force to the wall. The sinking process is stable and the tension force is controllable. The sinking depth can be precisely adjusted according to the excavation progress to achieve synchronous operation of excavation and sinking.

[0019] (5) The automatic spray curing device can be raised and lowered with the pipe rack to adapt to the curing needs of walls at different heights. Based on the automatic control of temperature and humidity sensors, it can achieve precise curing and improve the uniformity of concrete strength.

[0020] (6) There is no need to use the traditional full-depth trenching construction method. Only a guide trench for the first layer positioning needs to be excavated, which can reduce the amount of waste mud discharge. Attached Figure Description

[0021] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0022] Figure 1 This is a structural schematic diagram of the in-situ cast-in-place diaphragm wall construction system shown in the embodiments of this application; Figure 2 This is a schematic diagram of the prestressed sinking mechanism and the diaphragm wall as shown in the embodiments of this application; Figure 3 This is a schematic diagram of the in-situ cast-in-place diaphragm wall construction system for aiding settlement, as shown in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the tire frame shown in the embodiments of this application; Figure 5 This is a schematic diagram showing the state of the steel reinforcement skeleton tied to the jig in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of the tire frame in the retracted state as shown in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of the tire frame in the deployed state as shown in the embodiments of this application; Figure 8 This is a schematic diagram of the closed steel reinforcement cage of the columnar formwork shown in the embodiments of this application; Figure 9 This is a schematic diagram showing the columnar mold frame in the lifting state as illustrated in the embodiments of this application; Figure 10 This is a schematic diagram of the columnar mold frame structure shown in the embodiments of this application; Figure 11 This is a schematic diagram illustrating the columnar formwork in conjunction with concrete pouring, as shown in the embodiments of this application. Figure 12This is a schematic diagram of the layered casting and heightening state of the columnar formwork shown in the embodiments of this application.

[0023] Figure label: 1. Prestressed sinking mechanism; 10. Reverse thrust mechanism; 11. Steel strand; 12. Anchor pile; 2. Gantry frame; 3. Lifting mechanism; 4. Wagon frame; 40. Inner frame; 41. Outer frame; 42. Support component; 43. Connecting component; 44. Limiting seat; 45. Caster wheel; 5. Columnar formwork; 50. Drive assembly; 51. First axial member; 52. Second axial member; 53. Third axial member; 54. Fourth axial member; 55. Four-bar linkage; 55a. First link; 55b. Second link; 55c. Third link; 55d. Fourth link; 56. Casting template; 57. Limiting element; 6. Excavation equipment; 100. Foundation pit; 101. Reinforced concrete frame; 102. Diaphragm wall. Detailed Implementation

[0024] Preferred embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0025] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0026] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] Traditional diaphragm wall construction techniques face significant challenges in trenching under specific geological conditions, such as soft silty soil, alluvial layers containing boulders, and extremely hard rock. These conditions result in high risks of trench wall collapse and severely limit their applicability. The unit-segment, segment-by-segment construction method leaves the joints between wall segments as weak points. Insufficient construction precision or complex geological conditions can easily lead to misalignment between adjacent wall segments and water leakage at joints, compromising the overall impermeability and structural integrity of the wall. Furthermore, the overall cost of trenching equipment, mud treatment, and the hoisting of large steel cages is high, and the generation of large amounts of waste mud does not meet the requirements of green construction.

[0028] In response, this application proposes an in-situ cast-in-place diaphragm wall construction system, which can realize in-situ binding and layered casting of the diaphragm wall reinforcement structure. Combined with a prestressed sinking mechanism to drive the wall to sink in layers, it eliminates the need for pre-excavation of trenches. This system can solve the problems of difficult trenching and easy leakage at joints under special geological conditions, and also saves the process of hoisting large steel cages. It has the advantages of improving construction efficiency and the integrity of the wall, reducing construction costs and waste mud discharge.

[0029] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0030] See Figures 1 to 3 This application proposes an in-situ cast-in-place diaphragm wall construction system, including several sets of prestressed sinking mechanism 1 and several gantry frames 2 connected end to end. The gantry frames 2 are arranged around the foundation pit 100 to be constructed. Each gantry frame 2 is provided with at least two sets of lifting mechanism 3 at intervals along its own length direction. Each gantry frame 2 is correspondingly equipped with a jig 4 and a columnar formwork 5. The lifting mechanism 3 is used to drive the jig 4 to rise and fall when binding the steel reinforcement skeleton 101, and to drive the column formwork 5 to rise and fall when pouring the diaphragm wall 102. The frame 4 is used for in-situ binding of the steel reinforcement skeleton 101. Each steel reinforcement skeleton 101 is connected end to end along the perimeter of the foundation pit 100 to form a continuous steel reinforcement structure. The continuous steel reinforcement structure is provided with a reserved channel for steel strands to pass through. Each columnar formwork 5 is used to close the two sides of the steel reinforcement skeleton 101 along the width direction of the gantry frame 2, and adjacent columnar formwork 5 are joined together to enclose the continuous steel reinforcement structure to form a closed cavity of the diaphragm wall 102 to be poured. The prestressed sinking mechanism 1 includes a pusher mechanism 10, steel strands 11, and anchor piles 12. The anchor piles 12 are spaced apart below the guide groove along the construction axis of the diaphragm wall 102. One end of the steel strand 11 is connected to the anchor pile 12, and the other end is connected to the pusher mechanism 10 after passing through a reserved channel of continuous steel reinforcement structure. The pusher mechanism 10 is located at the top of the diaphragm wall 102 and is used to tension the steel strands 11 and apply a downward reaction force to the diaphragm wall 102 so that the diaphragm wall 102 breaks through the soil and sinks. The system is equipped with a fixed pulley assembly (not shown). After the first layer of steel reinforcement skeleton is tied and formed on the outside of the guide groove, it is hoisted into the guide groove by the lifting mechanism 3 in conjunction with the fixed pulley assembly. The system is configured to continue subsequent layers of reinforcement binding, formwork closure, and pouring construction on the top surface of the already poured diaphragm wall 102.

[0031] Specifically, all gantry frames 2 are set directly above the guide groove along the construction axis of the diaphragm wall 102. After multiple sets of gantry frames 2 are rigidly connected end to end, they form an integrated closed-loop working platform surrounding the foundation pit 100, providing a unified working bearing foundation for the subsequent in-situ binding of steel bars, layered pouring, and wall sinking. The number of prestressed sinking mechanisms 1 can be determined comprehensively based on the circumferential length of the diaphragm wall 102, the height of a single layer, the wall thickness, the soil lateral resistance, and the thrust of a single reverse thrust mechanism 10.

[0032] In this embodiment, the gantry frame 2 is a vertical load-bearing support structure with a gantry-shaped transparent working space. It can be flexibly selected from forms such as gantry frames, welded steel trusses, prefabricated steel structure frames, and modular aluminum alloy frames according to the needs of the construction scenario. It can also be replaced by other support structures with the same vertical load-bearing capacity and the ability to provide span working space, to adapt to the load-bearing capacity requirements and assembly efficiency requirements of different projects.

[0033] The lifting mechanism 3 is installed on the top truss of the gantry frame 2. It can be equipped with equipment possessing vertical linear drive capabilities, such as winches, electric hoists, or hydraulic jacking cylinders, to achieve the vertical lifting and lowering of the formwork frame 4 and the columnar formwork frame 5. For easy switching, the formwork frame 4 and the columnar formwork frame 5 are connected to the lifting mechanism 3 via a detachable connection. Simultaneously, the lifting mechanisms 3 configured on each gantry frame 2 can be connected to the control system, which reduces system redundancy and allows construction personnel to synchronously control the actions of all lifting mechanisms 3 and the corresponding lifting mechanism 3 on each gantry frame 2 through a centralized control interface, ensuring the coordination of multi-station operations.

[0034] The jig 4 is used for in-situ binding of single-section steel reinforcement skeleton 101, and at the same time as binding the steel reinforcement skeleton 101, a pre-set channel (such as a steel pipe) for threading steel strands 11 is installed according to the design layout of the prestressed sinking mechanism 1. After the single-section steel reinforcement skeleton 101 is bound, it is joined end to end along the circumference of the guide groove to form a continuous steel reinforcement structure. At the same time, the reserved channel (steel pipe), tie rod and other necessary embedded parts are installed. Then, the columnar formwork 5 closes the two sides of the steel reinforcement skeleton 101 along the width direction of the gantry frame 2. After the adjacent columnar formwork 5 are joined circumferentially, they jointly enclose the continuous steel reinforcement structure to form a closed cavity of the diaphragm wall 102 to be poured. After the concrete is poured and cured, a single-layer diaphragm wall 102 is formed.

[0035] The prestressed sinking mechanism 1 includes a thrust mechanism 10, steel strands 11, and anchor piles 12. The anchor piles 12 are spaced apart below the guide groove along the construction axis of the diaphragm wall 102, and their positions correspond to the retaining construction area below the gantry crane 2. During implementation, rotary drilling or impact drilling is used to construct the installation holes for the anchor piles 12 in the foundation pit 100. The bottom of the anchor piles 12 penetrates the rock stratum as the bearing layer. Concrete is poured into the pile holes, and steel strands 11 are pre-embedded. The other end of the steel strands 11 extends upwards to the ground. A reserved channel pre-embedded within the reinforcing steel cage 101 serves as the passage for the steel strands 11. The thrust mechanism 10 is installed on the top surface of the formed diaphragm wall 102, and the steel strands 11 pass through the thrust mechanism 10. The thrust mechanism 10 tensions the steel strands 11, generating a downward reaction force. Under the action of the anchor piles 12, this pulls the diaphragm wall 102 down as a whole. After the current layer of diaphragm wall 102 has sunk to the preset depth, the subsequent layers of rebar binding, formwork erection, and concrete pouring operations can be carried out directly on the top surface of the formed diaphragm wall 102. There is no need to repeatedly disassemble and assemble the gantry frame 2 and the lifting mechanism 3. The above procedures can be repeated to achieve the gradual raising and synchronous sinking of the diaphragm wall 102 until the diaphragm wall 102 reaches the design elevation.

[0036] In the design of this application, the construction process of the current layer diaphragm wall 102 is significantly different from that of the subsequent layers. This is because the current layer diaphragm wall 102 needs to serve as the initial base of the entire diaphragm wall 102 structure. Therefore, it is necessary to complete the initial positioning through a pre-excavated guide trench, so as to provide a benchmark for the subsequent layer extension construction and wall settlement, and avoid wall overturning and displacement problems during the subsequent foundation pit 100 excavation and prestressed sinking process.

[0037] Due to the specific positioning requirements of the first-floor construction, when using the formwork 4 to bind the steel reinforcement skeleton 101 of the current floor diaphragm wall 102, the formwork 4 is pre-positioned in the outer working area of ​​the guide groove. It can independently complete the binding and forming of a single section of the steel reinforcement skeleton 101 without connecting to the lifting mechanism 3. After the steel reinforcement skeleton 101 is bound, the lifting mechanism 3 is then connected to the formwork 4. Since the initial position of the formwork 4 and the output end of the lifting mechanism 3 are not on the same vertical line, a pulley assembly needs to be added at the corresponding position of the gantry frame 2 to adjust the lifting direction and correct the horizontal offset of the formwork 4, thus achieving stable lifting and alignment of the steel reinforcement skeleton 101. Similarly, the formwork erection of the columnar formwork 5 uses fixed pulleys for alignment assistance to ensure that the formwork position coincides with the axis of the guide groove. After the first-floor steel reinforcement skeleton 101 is hoisted into the guide groove by the lifting mechanism 3, the docking operation of each section of the steel reinforcement skeleton 101 can be completed circumferentially. Simultaneously, the reserved channels for the steel strands 11, tie rods, and other embedded parts are installed, ultimately forming the complete first-floor steel reinforcement structure.

[0038] Furthermore, the gantry frame 2 includes a truss, columns, and diagonal braces. The truss is mounted on the top of the columns, and the diagonal braces are arranged at an angle, with both ends of the diagonal braces connected to the truss and the columns, respectively. The lifting mechanism 3 includes a winch, the output end of which is wound with a steel cable, and the end of the steel cable is provided with a shackle. The jig frame 4 and the columnar mold frame 5 are provided with multiple lifting lugs that are adapted to the shackles.

[0039] Furthermore, the frame 4 includes an inner frame 40, two outer frames 41 and several support members 42. The inner frame 40 is used to connect the output end of the lifting mechanism 3. The two outer frames 41 are respectively disposed on both sides of the inner frame 40 along the width direction of the gantry frame 2. The two ends of the support members 42 are respectively hinged to the inner frame 40 and the outer frames 41. The outer frame 41 is provided with a plurality of snap-fit ​​pieces 43 arranged in an array on its outer side. The snap-fit ​​pieces 43 are used to receive and position the reinforcing bars to be tied. When the inner frame 40 and the outer frame 41 are grounded, the outer frame 41 unfolds to form the binding and positioning station of the steel frame 101. When the lifting mechanism 3 drives the inner frame 40 to rise, the outer frame 41 rotates downward around the hinge point under the action of gravity and retracts, so that the jig 4 can be dislodged from the inside of the steel frame 101.

[0040] See Figure 6 and Figure 7 The jig 4 serves as the tooling carrier for rebar tying. Its core functions are to position and support the rebar, assist in the forming and demolding of the rebar skeleton 101, and specifically, it is assembled from an inner skeleton 40, two outer skeletons 41, and several support members 42. Driven by the lifting mechanism 3, the outer skeleton 41 can actively unfold and automatically retract. When the lifting mechanism 3 lowers the jig 4 to the working surface, and the inner skeleton 40 and the outer skeleton 41 land simultaneously or are on the same horizontal plane, the support members 42 are in a horizontal support state, the outer skeleton 41 is in its maximum unfolded position, and the spatial position of the snap-fit ​​members 43 arranged in an array on its outer side is fixed, forming a positioning station that matches the design dimensions of the rebar skeleton 101. It can stably support and position the transverse and longitudinal rebars, and assist in the tying and forming process. After the binding of the steel reinforcement cage 101 is completed, the lifting mechanism 3 lifts the inner cage 40 upwards. Under the action of gravity, the outer cage 41 rotates downwards around the hinge point between the support member 42 and the inner cage 40, and then retracts towards the inner cage 40, so that the overall lateral dimension of the jig 4 is greatly reduced, and it can be removed from the internal cavity of the steel reinforcement cage 101 without interference.

[0041] The inner frame 40, as the core load-bearing base of the frame 4, can be formed into a frame structure by welding shaped steel, rectangular steel pipes, or angle steel. Its top can be equipped with shackles or lifting lugs for detachable connection to the output end of the lifting mechanism 3. Two outer frames 41 are symmetrically arranged on both sides of the inner frame 40 along the width direction of the gantry frame 2. Their structure can be consistent with the inner frame 40, or a structure combining shaped steel and flat plates can be used depending on the length of the reinforcing bars. Several support members 42 are hinged at both ends to the inner frame 40 and the outer frame 41, respectively, specifically through pins and shaft end retaining rings to form rotatable hinge points. Several arrayed snap-fit ​​members 43 are provided on the outer side of the outer frame 41. The snap-fit ​​members 43 can be L-shaped rods, U-shaped plates, or irregularly shaped components with slots, and can be detachably fixed to the outer surface of the outer frame 41 by welding or bolts. The transverse and longitudinal spacing of adjacent snap-fit ​​members 43 can be flexibly adjusted according to the design spacing of the reinforcing bars in the reinforcing bar skeleton 101; this application does not impose a unique limitation on this.

[0042] Furthermore, the support member 42 can be hinged to the inner frame 40 and the outer frame 41 via hinges (not shown). These hinges may include a screw, a steel sleeve, and a steel pad. The support member 42 can be a long, narrow steel plate with round holes at both ends. The steel sleeve passes through these holes, and steel pads are connected to both ends of the sleeve, one of which is fixedly connected to the head of the screw. The inner frame 40 and outer frame 41 are threaded to the corresponding screws of the hinges. The screws are high-strength standard threaded components, serving as the hinge axis and threadedly connected to the inner and outer frames 41, enabling both fixed and detachable installation of the hinges. The support member 42 is a long, narrow steel plate with high-precision round holes at both ends pre-drilled to fit the steel sleeves. The steel sleeves are high-strength, wear-resistant steel pipes that pass through the pre-drilled round holes at both ends of the support member 42, providing a low-friction bearing surface for the rotation of the support member 42. The outer diameter of the steel sleeve is slightly smaller than the diameter of the round holes. Two steel pads are fixed to both ends of the steel sleeve, and one end of the pad is welded to the head of the screw. The three together form an integral hinge shaft, which restricts the axial movement of the steel sleeve.

[0043] Based on the above specific implementation, the outer frame 41 is hinged to the inner frame 40 via the support member 42. If the inner frame 40 is used as a reference plane, the outer frame 41 can rotate approximately 180° relative to the inner frame 40. When the working surface is horizontal, this rotational freedom does not affect the forming accuracy of the reinforcing steel frame 101. However, when the working surface is tilted, or when the top surface of the previously poured diaphragm wall 102 has a flatness deviation, a height difference easily occurs between the two inner frames 40, causing the outer frame 41 to fail to maintain horizontality after unfolding. This ultimately results in the next section of the tied reinforcing steel frame 101 failing to maintain verticality, affecting the docking accuracy of subsequent segments and the smoothness of the steel strand 11 threading. To address this technical problem, this application also provides a corresponding structure. Specifically, the inner frame 40 is provided with a limiting seat 44, which has a side surface parallel to the horizontal plane. When the support member 42 rotates to a horizontal state, the upper surface of the support member 42 fits against the side surface to limit the maximum upward rotation angle of the outer frame 41.

[0044] In this embodiment, the limiting seat 44 can be composed of components such as a fixing block, flange, pin, rod, or angle steel, and is made of high-strength metal material. When the support member 42 rotates to the horizontally extended position, the upper surface of the support member 42 completely fits against the side surface, forming a mechanical stop that prevents the support member 42 from continuing to rotate upward, thereby offsetting the height difference caused by unevenness of the working surface. With this setting, the forming accuracy of the rebar cage 101 and the safety of the binding operation can be improved. There is no need for operators to additionally adjust or check the horizontal state of the support member 42, which has the advantages of simplifying the operation process and improving work efficiency.

[0045] Furthermore, the inner frame 40 includes at least two vertically arranged inner longitudinal beams, and at least two inner transverse beams are horizontally connected between each of the inner longitudinal beams to form a rectangular frame structure; the support member 42 is hinged to the inner transverse beams via hinges, and the limiting seat 44 is fixed to the inner transverse beams and located directly above the hinge point of the hinges. The inner longitudinal beams and inner transverse beams can be made of structural steel (such as H-beams, I-beams, or square steel pipes) and are fixedly connected by welding, bolting, or riveting.

[0046] Correspondingly, the outer frame 41 includes at least two vertically arranged outer longitudinal beams, and at least two outer transverse beams are horizontally connected between each of the outer longitudinal beams. The outer longitudinal beams and outer transverse beams can be connected by welding or bolts to form a rectangular frame structure.

[0047] Furthermore, a caster wheel 45 is installed at the bottom of the outer frame 41. When the bottom surface of the caster wheel 45 is flush with the bottom surface of the inner frame 40, the support member 42 is in a horizontal state. Under this configuration, during the descent of the lifting mechanism 3 driving the frame 4, the contact form between the outer frame 41 and the working surface changes from sliding friction to rolling friction, which can improve the smoothness of the outer frame 41's unfolding action and avoid the problem of the inner frame 40 getting stuck with the working surface (such as the concrete base surface of the top of the diaphragm wall 102).

[0048] Furthermore, the snap-fit ​​component 43 includes a first snap-fit ​​component and a second snap-fit ​​component. The first snap-fit ​​component is equidistantly distributed on the outer frame 41 along the length direction of the gantry frame 2 and is used to position the longitudinal reinforcing bars. The second snap-fit ​​component is equidistantly distributed on the outer frame 41 along the height direction of the gantry frame 2 and is used to position the transverse reinforcing bars.

[0049] Specifically, the first clamp is a longitudinal rebar positioning structure, and the second clamp is a transverse rebar bearing structure. Since the longitudinal rebar cannot rely on the first clamp for self-weight bearing during installation, to improve construction safety, the first clamp is preferably an open-type clamp structure. When positioning the longitudinal rebar, the open structure allows for temporary limiting and fixing, effectively preventing the longitudinal rebar from overturning and becoming unstable. The second clamp can follow the aforementioned design, using rods or plates for fabrication. To further improve the reliability of rebar positioning and prevent rebar displacement or detachment during binding, the receiving end of the clamp 43 can be tilted upwards, preferably at an angle of 10° to 30°, allowing the rebar to naturally snap into place and remain stable without additional temporary fixing.

[0050] In some optional implementation scenarios, the first and second clamps can also be designed as adjustable sliding structures, with the position locked by matching bolts, thereby adapting to the process requirements of different binding widths and improving the versatility of the jig 4.

[0051] Through the above technical solution, this application can achieve rapid and accurate positioning of longitudinal and transverse steel bars through the snap-fit ​​connector 43, reducing errors and time consumption caused by manual adjustment. This not only improves the forming efficiency and binding accuracy of the steel bar cage 101, but also facilitates subsequent processes and comprehensively improves the overall construction quality.

[0052] Furthermore, the columnar mold frame 5 includes a drive assembly 50, a first axial member 51, a second axial member 52, a third axial member 53 and a fourth axial member 54 arranged sequentially along the circumference, and two sets of four-bar linkages 55 disposed at both ends of the columnar mold frame 5. The two ends of the first axial member 51, the second axial member 52, the third axial member 53 and the fourth axial member 54 are respectively connected to the hinge shafts of the two sets of four-bar linkages 55. The first axial member 51 is connected to the output end of the lifting mechanism 3. The first axial member 51 and the third axial member 53 are arranged radially opposite to each other. The second axial member 52 and the fourth axial member 54 are respectively hinged to the casting template 56. The drive assembly 50 is used to drive the third axial member 53 to approach or move away from the central axis of the columnar mold frame 5, so as to drive the two sets of casting templates 56 to move towards or away from each other.

[0053] See Figures 8 to 12 The columnar formwork 5 is used to achieve synchronous lifting and opening / closing adjustment of the casting template 56. The columnar formwork 5 has four axial members and four-bar linkages 55 located at both ends. The four axial members and the four-bar linkages 55 combine to form a prism-shaped skeleton. In the suspended state, the columnar formwork 5 maintains its axis parallel to the horizontal plane, that is, the four axial members extend horizontally. The four axial members are the first axial member 51, the second axial member 52, the third axial member 53, and the fourth axial member 54. Each four-bar linkage 55 has four hinge shafts. The two ends of the four axial members are respectively connected to the corresponding hinge shafts of the two sets of four-bar linkages 55, thereby realizing the radial expansion and contraction of the columnar formwork 5. As an optional embodiment, the axial members can also be directly used as the hinge shafts of the four-bar linkages 55 to realize the rotational connection between the four-bar linkages 55 and the axial members.

[0054] The output end of the lifting mechanism 3 is connected to the first axial member 51. When the lifting mechanism 3 lifts the columnar mold frame 5, the columnar mold frame 5 is suspended in the air, and the third axial member 53 is located directly below the first axial member 51, while the second axial member 52 and the fourth axial member 54 are located on the left and right sides respectively. In this structural layout, when the drive assembly 50 drives the third axial member 53 to approach or move away from the central axis of the columnar mold frame 5, the four-bar linkage 55 simultaneously drives the second axial member 52 and the fourth axial member 54 on both sides, so that the two synchronously approach or move away from the central axis of the columnar mold frame 5, thereby realizing the opposite closing or opposite opening movement of the two sets of casting templates 56, ensuring that the casting templates 56 can fall into both sides of the steel reinforcement cage 101 when descending, and close the steel reinforcement cage 101.

[0055] The drive assembly 50 can be implemented using structures with linear drive capabilities, such as hydraulic jacks, motor screw mechanisms, and motor traction mechanisms, depending on the construction load requirements.

[0056] During operation, the lifting mechanism 3 first lifts the column-shaped formwork 5. After the column-shaped formwork 5 is raised above the reinforcing steel cage 101, the drive assembly 50 drives the third axial member 53 to approach the central axis of the column-shaped formwork 5. The pouring templates 56 move in opposite directions, and the lifting mechanism 3 drives the column-shaped formwork 5 to descend as a whole. During the descent, the pouring templates 56 fall into both sides of the reinforcing steel cage 101. Then, the drive assembly 50 drives the third axial member 53 away from the central axis of the column-shaped formwork 5. The pouring templates 56 move towards each other until they fit against the sides of the reinforcing steel cage 101, thereby forming a closed concrete pouring cavity outside the reinforcing steel cage 101.

[0057] Furthermore, the first axial member 51, the second axial member 52, the third axial member 53 and the fourth axial member 54 are all long strip rods. Each axial member can preferably be made of seamless round steel pipe as the main material. Each axial member can be assembled and connected to the hinge shaft of the four-bar linkage 55 by welding and bolting.

[0058] Furthermore, the four-bar linkage 55 includes a first link 55a, a second link 55b, a third link 55c, and a fourth link 55d that are hinged end to end in sequence; the length of the first link 55a is equal to the length of the fourth link 55d, the length of the second link 55b is equal to the length of the third link 55c, and the length of the first link 55a is greater than the length of the second link 55b; when the second link 55b and the third link 55c are collinear, the distance between the two sets of casting templates 56 reaches its maximum value.

[0059] With this configuration, when the four-bar linkage 55 is in the retracted state, the second link 55b and the third link 55c can be folded closer to the central axis of the columnar formwork 5, effectively reducing the radial cross-sectional size of the columnar formwork 5 when it is horizontally suspended, so that the columnar formwork 5 as a whole can smoothly pass through narrow slots or dense steel bar gaps, improving the device's passability and operational flexibility in complex construction scenarios. When the second link 55b and the third link 55c move to a collinear state, the radial expansion of the second axial member 52 and the fourth axial member 54 reaches its maximum value. When this position matches the maximum extension stroke of the hydraulic jack, the four-bar linkage 55 can be placed at a dead point. If the second link 55b and the third link 55c are subjected to an outward force, they cannot generate a torque to rotate the link outward, thus forming a mechanical self-locking limit. This prevents the hinge axis of the second link 55b and the third link 55c from protruding outward into the concrete pouring cavity, effectively ensuring the flatness of the surface of the cast diaphragm wall 102, and also preventing the hinge axis from being encased in concrete and causing the mechanism to jam.

[0060] Furthermore, the drive assembly 50 is a hydraulic jack, which is connected to the first axial member 51 via a bracket, and the output end of the hydraulic jack is connected to the third axial member 53.

[0061] In this embodiment, the hydraulic jack has the advantages of stable hydraulic drive output load and large driving force, which can overcome the resistance when the pouring formwork 56 is pressed against the reinforcing steel skeleton 101. Moreover, the extension and retraction speed of the telescopic rod is controllable, which can precisely adjust the opening and closing distance of the two sets of pouring formwork 56, ensuring the installation accuracy of the pouring formwork 56 and the forming quality of the concrete. At the same time, the hydraulic jack itself has pressure-holding and self-locking characteristics, which can stably maintain the lifting pressure without continuously providing power during the pouring process, resisting the lateral pressure of the concrete and preventing the pouring formwork 56 from displacement and deformation. Furthermore, the hydraulic jack occupies little space and does not require additional complex transmission mechanisms, which can simplify the overall structural layout. Finally, the hydraulic jack is well adapted to the humid and dusty underground engineering construction environment, which can significantly reduce the on-site maintenance cost and failure rate of the device.

[0062] Furthermore, the casting template 56 includes a support frame and a panel laid inside the support frame. The top of the support frame is provided with a mounting seat, and the mounting seat is provided with an assembly hole extending along the axial direction of the columnar template 5. The second axial member 52 and the fourth axial member 54 respectively pass through the assembly holes of the corresponding mounting seats.

[0063] In this embodiment, the support frame is a rectangular rigid frame structure, welded from structural steel such as I-beams and channel steel. The mounting base can be prefabricated from thickened steel plates and welded to the outer wall of the top vertical rod of the support frame. The steel plate extends outward from the side facade of the support frame to form a cantilever section. Assembly holes are opened in the cantilever section of the mounting base, which can avoid structural interference between axial components and the main body of the support frame, and at the same time ensure the uniformity of stress and structural reliability of the rotating connection nodes. The panel can preferably be made of plastic steel plate, which is fixed to the inner surface of the support frame by bolt fastening or structural adhesive bonding. Using plastic steel plate as the forming surface material can reduce the difficulty of demolding the template and reduce defects such as sticking and pitting on the surface of the formed wall. At the same time, plastic steel plate has excellent corrosion resistance and can resist the erosion of underground humid environments, mud media and alkaline hydration products of concrete, and the template has a high reuse rate. In addition, the low self-weight of plastic steel plate can reduce the overall load of the column formwork 5, reduce the power configuration requirements of the lifting mechanism 3 and the drive component 50, and further improve the operational flexibility and construction safety of the device.

[0064] Furthermore, the columnar mold frame 5 also includes a limiting member 57, one end of which is rotatably connected to the second axial member 52, and the other end is engaged with the fourth axial member 54.

[0065] Specifically, the limiting member 57 is a long strip of steel plate, with a hinged assembly hole at one end for the second axial member 52 to pass through, and a U-shaped slot with an opening facing downwards at the other end. When the casting template 56 moves to a preset position that fits against the outer side of the reinforcing steel frame 101, simply rotating the limiting member 57 engages its U-shaped slot with the rod of the fourth axial member 54, achieving rapid mechanical locking of the relative positions of the two axial members. With this configuration, the power supply to the drive assembly 50 can be cut off during the concrete curing stage, reducing energy consumption and equipment standby losses. On the other hand, it serves as a redundant safety limit for the casting template 56, directly offsetting the lateral expansion force generated during concrete pouring, preventing template displacement, expansion, and other construction accidents when the drive assembly 50 loses pressure or its power is interrupted, significantly improving the reliability and safety of the pouring operation. Correspondingly, the number of limiting members 57 can be freely set according to the axial length of the columnar formwork 5.

[0066] Furthermore, the reverse thrust mechanism 10 includes a through-hole jack and a reaction frame. The steel strand 11 is inserted into the through-hole jack, and the through-hole jack is fixed to the top end face of the diaphragm wall 102 by the reaction frame. When the through-hole jack tensions the steel strand 11, it pushes the diaphragm wall 102 to sink.

[0067] In this embodiment, the through-hole jack has a central through-hole structure, allowing the steel strand 11 to be threaded along the axis, ensuring unbiased and lossless transmission of tension force. Combined with the hydraulic system, precise control of the tension force can be achieved. The reaction frame is made of high-strength steel, providing rigid support for the jack and ensuring that the tension reaction force is evenly transmitted to the top surface of the diaphragm wall 102, avoiding wall damage caused by localized stress concentration. Anchor piles 12 are spaced along the construction axis of the diaphragm wall 102 below the guide groove, with the pile bottom embedded in the bearing stratum of the rock layer. One end of the steel strand 11 is anchored in the anchor pile 12, and the other end extends upwards out of the ground and passes through the reserved channel of the reinforcing steel frame 101. The through-hole jack is installed on the top surface of the cast-in-place diaphragm wall 102 via a reaction frame. The steel strand 11 passes through the center hole of the jack and is fixed by an anchor. When the jack is tensioned, the reaction frame evenly transmits the reaction force of the tension to the top surface of the diaphragm wall 102, forming a downward prestressed thrust that drives the wall to sink smoothly. The control system can simultaneously adjust the tension and tension rate of multiple jacks, and can control the verticality deviation of the sinking of the diaphragm wall 102.

[0068] Furthermore, the system also includes an automatic spray curing device (not shown) and a soil removal device 6; The automatic sprinkler curing device includes a pipe rack, pipes, sprinkler heads, temperature and humidity sensors, and a controller. The pipe rack slides along the height direction with the gantry frame 2 via a slide rail. The pipe rack is provided with several ropes at intervals. The ropes are wrapped around the gantry frame 2 and then tied to the gantry frame 2. The pipes are fixed on the pipe rack and are arranged around the foundation pit 100 to be constructed. The pipes are provided with several sprinkler heads, and the spray direction of the sprinkler heads is inclined downward at 45°. The excavation device 6 includes a conveyor belt. An installation frame is provided inside the foundation pit 100. The conveyor belt is inclined through the installation frame. The feed end of the conveyor belt is located inside the foundation pit 100, and the discharge end is located outside the foundation pit 100. When the diaphragm wall 102 is in the maintenance state, the spray head follows the pipe rack down to one side of the diaphragm wall 102, and the controller controls the spraying duration and spraying interval based on the humidity and temperature information from the temperature and humidity sensor.

[0069] In this embodiment, the pipe rack is slidably connected to the gantry frame 2 via vertical slide rails, allowing it to adaptively rise and fall along the construction height of the diaphragm wall 102 to match the curing operation requirements of different construction stages. The pipe rack is positioned with the aid of ropes wound around the gantry frame 2, ensuring stability during lifting and spraying operations. Pipes are laid around the foundation pit 100 along the pipe rack, forming a closed or semi-closed loop spraying circuit. Spray heads inclined downwards at 45° are spaced on the pipe body, ensuring that water mist evenly covers the sides of the diaphragm wall 102, preventing water flow from eroding the wall and ensuring uniform adhesion of the curing liquid. Temperature and humidity sensors collect ambient temperature and humidity data in real time. The controller automatically starts and stops the spraying and adjusts the spraying duration and interval based on the monitoring data: spraying starts when the ambient humidity is below a threshold or the temperature is above a threshold, and automatically stops when the humidity reaches the target, achieving refined and intelligent curing. During curing operations, the spray heads descend with the pipe rack to the side of the diaphragm wall 102, dynamically adjusting the spraying strategy based on real-time temperature and humidity data to ensure that the concrete is always in the optimal temperature and humidity curing environment.

[0070] Through the above-described scheme, the automatic spray curing device can automate and intelligently manage the curing process, avoiding omissions or over-curing issues inherent in manual curing. This improves curing efficiency and quality, reduces early-stage shrinkage cracks in concrete, and ensures the strength and durability of the diaphragm wall 102. The accompanying inclined conveyor belt soil removal device 6 continuously transports excavated soil from the foundation pit 100 to the ground for direct connection with transport vehicles, simplifying the soil removal process and improving site cleanliness and transfer efficiency. The coordinated operation of the automatic spray curing device and the soil removal device enhances construction continuity while ensuring the quality of the completed wall, offering advantages such as shortened construction time and reduced labor costs.

[0071] Corresponding to the foregoing embodiments, this application also provides a construction method based on the above-described in-situ cast-in-place diaphragm wall 102 construction system, comprising the following steps: S1. Several pile holes are constructed at intervals on the construction axis of the diaphragm wall 102. Steel strands 11 are installed on the precast foundation pile reinforcement cage. The reinforcement cage is lowered into the pile hole and concrete is poured to form an anchor pile 12. One end of the steel strand 11 is anchored inside the anchor pile 12, and the other end extends out of the ground for a predetermined length. S2. Construct the excavation device 6 inside and outside the foundation pit 100. After the equipment is in place, assemble the gantry frame 2, the lifting mechanism 3 and the automatic spray curing device. Hoist the jig 4 and the column formwork 5 to the corresponding working positions of the gantry frame 2. Excavate the guide groove of the diaphragm wall 102 and complete the groove wall support. S3. Tie a single section of steel reinforcement skeleton 101 in situ on the jig 4. Lower the steel reinforcement skeleton 101 into the guide groove through the lifting mechanism 3. Connect each section of steel reinforcement skeleton 101 in sequence along the circumference of the foundation pit 100 to form a continuous steel reinforcement structure. Drive the columnar formwork 5 to close to seal the two sides of the steel reinforcement structure and form a closed cavity. Pour the concrete of the current layer diaphragm wall 102 to a height of 2m. S4. After the current layer of diaphragm wall 102 reaches the design strength, the excavator inside the foundation pit 100 excavates the soil layer by layer from the side away from the soil removal device 6 toward the soil removal device 6. The soil that is far away from the soil removal device 6 is transferred to the feeding end of the soil removal device 6 by the transfer equipment. The soil removal device 6 then transports the soil to the outside of the foundation pit 100 and completes the soil removal by the external transport vehicle. S5. After the excavation depth of each layer in the foundation pit reaches 1m, the reverse thrust mechanism 10 is activated to tension the steel strand 11, applying a downward prestressed reaction force to the diaphragm wall 102 of the current layer, driving the wall to sink as a whole by 1m; after excavating to a depth of 1m, the steel strand 11 is tensioned again, driving the wall to sink a second time by 1m, the tensioning operation is stopped, and the construction work of the current layer is completed. S6. On the top surface of the diaphragm wall 102 that has been formed in the previous layer, repeat the steel reinforcement binding, formwork pouring, layered excavation and sinking operation of steps S3 to S5 until the diaphragm wall 102 sinks to the design elevation. Finally, the foundation pit 100 is excavated to the design depth.

[0072] Through the above technical solution, this application provides a systematic, controllable, and efficient in-situ cast-in-place diaphragm wall 102 construction process. This method pre-constructs anchor piles 12 and pre-embeds steel strands 11, providing a reliable anchoring foundation for the subsequent sinking of the diaphragm wall 102. After the equipment is in place, a formwork 4 is used to in-situ tie the reinforcing steel skeleton 101 and cooperate with the columnar formwork 5 to form a closed cavity for concrete pouring of the current layer of the diaphragm wall 102. Subsequently, through the synergistic effect of layered excavation and prestressed sinking mechanism, the sinking of the diaphragm wall 102 is achieved, avoiding problems such as wall tilting and uneven settlement that may occur in traditional construction. The introduction of an automatic spray curing device ensures the strength development of the concrete during the curing period. This iterative process of reinforcing steel binding, formwork pouring, layered excavation, and sinking assistance allows the diaphragm wall 102 to extend continuously and stably downwards to the design elevation, greatly improving construction efficiency and project quality, while optimizing the earthwork removal process and reducing construction risks.

[0073] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An in-situ cast-in-place diaphragm wall construction system, characterized in that, It includes several sets of prestressed sinking mechanisms and several gantry frames connected end to end. The gantry frames are arranged around the foundation pit to be constructed. Each gantry frame is provided with at least two sets of lifting mechanisms at intervals along its own length. Each gantry frame is correspondingly equipped with a jig and a columnar formwork. The lifting mechanism is used to drive the jig frame to rise and fall during binding and to drive the column formwork frame to rise and fall during the pouring of the diaphragm wall. The frame is used for in-situ binding of the reinforcing steel skeleton. Each reinforcing steel skeleton is connected end to end along the perimeter of the foundation pit to form a continuous reinforcing steel structure. The continuous reinforcing steel structure is provided with a reserved channel for the steel strand to be threaded through. Each columnar formwork is used to close the two sides of the steel reinforcement skeleton along the width direction of the gantry frame, and adjacent columnar formworks are joined together to enclose the continuous steel reinforcement structure to form a closed cavity for the diaphragm wall to be poured. The prestressed sinking mechanism includes a push mechanism, steel strands, and anchor piles. The anchor piles are spaced apart below the guide groove along the construction axis of the diaphragm wall. One end of the steel strand is connected to the anchor pile, and the other end passes through a reserved channel of continuous steel reinforcement structure and is connected to the push mechanism. The push mechanism is located at the top of the diaphragm wall and is used to tension the steel strands and apply a downward reaction force to the diaphragm wall to cause the diaphragm wall to break through the soil and sink. The system is equipped with a fixed pulley assembly. After the first layer of steel reinforcement skeleton is tied and formed on the outside of the guide groove, it is hoisted into the guide groove by the lifting mechanism in conjunction with the fixed pulley assembly. The system is configured to continue subsequent layers of reinforcement binding, formwork closure, and pouring construction on the top surface of the already poured diaphragm wall.

2. The in-situ cast-in-place diaphragm wall construction system according to claim 1, characterized in that, The gantry frame includes a truss, columns, and diagonal braces. The truss is mounted on the top of the columns, and the diagonal braces are arranged at an angle, with both ends of the diagonal braces connecting to the truss and the columns, respectively. The lifting mechanism includes a winch, the output end of which is wound with a steel cable, the end of which is provided with a shackle, and the jig and columnar mold frame are provided with multiple lifting lugs that are adapted to the shackles.

3. The in-situ cast-in-place diaphragm wall construction system according to claim 1, characterized in that, The frame includes an inner frame, two outer frames, and several support members. The inner frame is used to connect to the output end of the lifting mechanism. The two outer frames are respectively located on both sides of the inner frame along the width direction of the gantry frame. The two ends of the support members are respectively hinged to the inner frame and the outer frame. The outer frame is provided with several snap-fit ​​components arranged in an array on its outer side. The snap-fit ​​components are used to receive and position the reinforcing bars to be tied. When the inner and outer frames are grounded, the outer frame unfolds to form the binding and positioning station for the steel reinforcement frame. When the lifting mechanism drives the inner frame to rise, the outer frame rotates downward around the hinge point and retracts under the action of gravity, so that the jig can be dislodged from the inside of the steel frame.

4. The in-situ cast-in-place diaphragm wall construction system according to claim 3, characterized in that, The inner frame is provided with a limiting seat, which has a side surface parallel to the horizontal plane. When the support rotates to the horizontal state, the upper surface of the support fits against the side surface to limit the maximum angle of upward rotation of the outer frame. The bottom of the outer frame is equipped with casters. When the bottom surface of the casters is flush with the bottom surface of the inner frame, the support is in a horizontal state. The snap-fit ​​component includes a first snap-fit ​​component and a second snap-fit ​​component. The first snap-fit ​​component is equidistantly distributed on the outer frame along the length of the gantry frame and is used to position the longitudinal reinforcing bars. The second snap-fit ​​component is equidistantly distributed on the outer frame along the height of the gantry frame and is used to position the transverse reinforcing bars. The second card is tilted upwards at an angle of 10° to 30°.

5. The in-situ cast-in-place diaphragm wall construction system according to claim 1, characterized in that, The columnar mold frame includes a drive assembly, a first axial member, a second axial member, a third axial member and a fourth axial member arranged sequentially along the circumference, and two sets of four-bar linkages located at both ends of the columnar mold frame in the axial direction. The two ends of the first axial member, the second axial member, the third axial member, and the fourth axial member are respectively connected to the hinge shafts of two sets of four-bar linkages; The first axial member is connected to the output end of the lifting mechanism. The first axial member and the third axial member are arranged radially opposite to each other. The second axial member and the fourth axial member are respectively hinged to the casting template. The drive assembly is used to drive the third axial member to move closer to or away from the central axis of the columnar mold frame, so as to drive the two sets of casting templates to move towards or away from each other.

6. The in-situ cast-in-place diaphragm wall construction system according to claim 5, characterized in that, The first axial member, the second axial member, the third axial member, and the fourth axial member are all long strip-shaped rods; The four-bar linkage includes a first link, a second link, a third link, and a fourth link that are hinged end to end in sequence; the length of the first link is equal to the length of the fourth link, the length of the second link is equal to the length of the third link, and the length of the first link is greater than the length of the second link; when the second link and the third link are collinear, the distance between the two sets of casting templates reaches its maximum value.

7. The in-situ cast-in-place diaphragm wall construction system according to claim 6, characterized in that, The driving component is a hydraulic jack, which is connected to the first axial component via a bracket, and the output end of the hydraulic jack is connected to the third axial component. The casting template includes a support frame and a panel laid inside the support frame. The top of the support frame is provided with a mounting seat. The mounting seat is provided with an assembly hole extending along the axial direction of the column-shaped template. The second axial member and the fourth axial member respectively pass through the assembly hole of the corresponding mounting seat. The columnar mold frame also includes a limiting member, one end of which is rotatably connected to the second axial member, and the other end is engaged with the fourth axial member.

8. The in-situ cast-in-place diaphragm wall construction system according to claim 1, characterized in that, The reverse thrust mechanism includes a through-hole jack and a reaction frame. The steel strand is threaded through the through-hole jack, and the through-hole jack is fixed to the top end face of the diaphragm wall by the reaction frame. When the through-hole jack tensions the steel strand, it pushes the diaphragm wall to sink.

9. The in-situ cast-in-place diaphragm wall construction system according to claim 1, characterized in that, It also includes automatic sprinkler curing devices and soil removal devices; The automatic sprinkler curing device includes a pipe rack, pipes, sprinkler heads, temperature and humidity sensors, and a controller. The pipe rack slides along the height direction with a slide rail and is connected to a gantry frame. The pipe rack is provided with several ropes at intervals. The ropes are wrapped around the gantry frame and tied to the gantry frame. The pipes are fixed on the pipe rack and are arranged around the foundation pit to be constructed. The pipes are provided with several sprinkler heads. The spray direction of the sprinkler heads is inclined downward at 45°. The excavation device includes a conveyor belt, and an installation frame is provided in the foundation pit. The conveyor belt is inclined through the installation frame, with the feed end of the conveyor belt located inside the foundation pit and the discharge end located outside the foundation pit. When the diaphragm wall is under maintenance, the spray head descends to one side of the diaphragm wall along with the pipe rack. The controller controls the spraying duration and spraying interval based on the humidity and temperature information from the temperature and humidity sensors.

10. A construction method based on the in-situ cast-in-place diaphragm wall construction system as described in claim 9, characterized in that, Includes the following steps: S1. Several pile holes are constructed at intervals along the construction axis of the diaphragm wall. Steel strands are installed on the precast foundation pile reinforcement cage. The reinforcement cage is lowered into the pile hole and concrete is poured to form an anchor pile. One end of the steel strand is anchored inside the anchor pile, and the other end extends out of the ground by a predetermined length. S2. Construct soil removal equipment inside and outside the foundation pit. After the equipment is in place, assemble the gantry frame, lifting mechanism and automatic spray curing device. Hoist the formwork and column formwork to the corresponding working position of the gantry frame. Excavate the diaphragm wall guide trench and complete the trench wall support. S3. Tie a single section of steel reinforcement cage in situ on the formwork, and lower the steel reinforcement cage into the guide groove through the lifting mechanism. Connect each section of steel reinforcement cage in sequence along the perimeter of the foundation pit to form a continuous steel reinforcement structure. Drive the columnar formwork to close to seal the two sides of the steel reinforcement structure, forming a closed cavity. Pour the concrete for the ground diaphragm wall of the current layer to a height of 2m. S4. After the current layer of diaphragm wall has been cured to the design strength, the excavator inside the foundation pit will excavate the soil layer by layer from the side away from the soil removal device towards the soil removal device. The soil that is far away from the soil removal device will be transferred to the feeding end of the soil removal device by the transfer equipment. The soil removal device will then transport the soil to the outside of the foundation pit and complete the soil removal by the external transport vehicle. S5. After the excavation depth in the foundation pit reaches 1m, the reverse thrust mechanism is activated to tension the steel strands, apply a downward prestressed reaction force to the diaphragm wall of the current layer, and drive the wall to sink 1m as a whole; after excavating to a depth of 1m, the steel strands are tensioned again, driving the wall to sink 1m a second time, the tensioning operation is stopped, and the construction work of the current layer is completed. S6. On the top surface of the diaphragm wall that has been formed in the previous layer, repeat the steel reinforcement binding, formwork pouring, layered excavation and sinking operation of steps S3 to S5 until the diaphragm wall sinks to the design elevation. Finally, the foundation pit is excavated to the design depth.

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