Deep foundation pit support and dismantling method thereof

Abstract

The invention relates to the technical field of building construction, in particular to a deep foundation pit support and a dismantling method thereof. According to the technical scheme, fixing frames are arranged at the two ends of each concrete precast block, fixing holes are formed in the fixing frames, locking pieces are installed in the fixing holes in an inserted mode, every two adjacent concrete precast blocks are locked and fixed through the locking pieces on the fixing holes, and the concrete precast blocks are installed in a foundation pit to serve as a supporting cross beam after being spliced. The concrete precast blocks and the locking pieces are ingeniously matched to form a stable supporting cross beam structure, the evenly-distributed fixing holes ensure uniform connection stress, and the stability and the bearing capacity of deep foundation pit supporting are improved. Meanwhile, the unique dismantling method guarantees safety and orderliness of the dismantling process, part dismantling, environment evaluation, safe operation, progress monitoring, stability monitoring and the like are covered, the parts can be effectively recycled, and efficient utilization of resources and safety guarantee of construction are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a deep foundation pit support and a removal method thereof. Background Art

[0002] Deep foundation pit support refers to the measures of support, reinforcement and protection of the side walls of deep foundation pits and the surrounding environment to ensure the safety of underground structure construction and the surrounding environment of the foundation pit. With the rapid development of my country's economy, urban space is becoming more and more dense, especially in coastal development cities. The number of deep foundation pit projects encountered is increasing, and most of them are located in downtown areas of cities. As a result, the requirements for foundation pit support structures are becoming more and more stringent and higher. The internal support can meet the requirements of foundation pit deformation control while ensuring the safety of the foundation pit slope. It is a structural form composed of a retaining structure and an internal support system. It has high rigidity, small deformation, and can effectively control the deformation of the retaining structure and the surrounding terrain. It is precisely because of the importance of the internal support that the removal of the internal support has become an important factor directly affecting the stability of the foundation pit.

[0003] After searching, the patent with the patent announcement number CN201310385792.4 discloses a deep foundation pit support and its dismantling method. Although the device is used by setting multiple sections of concrete and multiple steel bars, the adjacent concrete blocks are bonded by a sulfur clay interlayer, and the multiple steel bars penetrate the multiple sections of concrete and the sulfur clay interlayer, and the sulfur clay interlayer is pre-buried with an electric heater. The dismantling method of the deep foundation pit support includes step 1: turning on the electric heater to heat the sulfur clay interlayer; step 2: when the sulfur clay interlayer becomes soft due to heat, removing the sulfur clay interlayer to expose the steel bars penetrating between adjacent concrete blocks; step 3: cutting off the steel bars between adjacent concrete blocks to disconnect the adjacent concrete blocks from each other, and step 4: lifting the concrete blocks out of the deep foundation pit. The above-mentioned deep foundation pit support and its demolition method can effectively reduce the demolition cost of deep foundation pit support while maintaining demolition efficiency and green environmental protection. However, when the device is used, it is also necessary to embed an electric heater in the sulfur mastic interlayer. The electric heater is a key component in the demolition method and is used to heat the sulfur mastic interlayer to soften and remove it. If the electric heater fails, the sulfur mastic interlayer may not be effectively heated and softened, which will make the demolition process impossible or require other more complex and costly methods to replace it. If the electric heater fails during the demolition process, additional repair or replacement costs may be required. In addition, demolition delays caused by electric heater failures may increase the time cost of the project, including possible delay penalties and additional labor costs. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a deep foundation pit support and a method for dismantling the same, which solves the problems raised in the background technology.

[0005] The solution of the present invention to solve the above technical problems is as follows:

[0006] A deep foundation pit support, comprising a precast concrete block, two ends of which are provided with a fixing frame, the fixing frame is provided with a fixing hole, a locking piece is inserted and installed in the fixing hole, two adjacent precast concrete blocks are locked and fixed by the locking pieces on the fixing holes, and the precast concrete blocks are installed in the foundation pit as a supporting beam after being spliced;

[0007] The concrete prefabricated block is provided with a through hole, an embedded connector is installed in the through hole, the embedded connector is provided with a sleeve, both ends of the sleeve are provided with a receiving groove, a threaded rod is movably installed in the receiving groove, and two adjacent concrete prefabricated blocks are connected and fixed by the threaded rod and the connecting sleeve;

[0008] The locking member is provided with an end cover, the end cover is provided with an insertion rod, the insertion rod is provided with an insertion hole, a pin rod is inserted in the insertion hole, the insertion rod is sleeved with a pressure cover, and a spring is installed in the pressure cover.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, a limiting plate is connected to the threaded rod, and the threaded rod is slidably installed in the accommodating groove through the limiting plate.

[0011] The beneficial effects of adopting the above further scheme are:

[0012] The setting of the limit plate makes the sliding of the threaded rod in the receiving groove more stable and controllable. When connecting adjacent concrete precast blocks, it can prevent the threaded rod from excessively deflecting or shaking in the receiving groove, ensuring the position accuracy of the threaded rod during the connection process, thereby ensuring the connection accuracy between adjacent concrete precast blocks. When subjected to external force, the limit plate can share part of the force, reduce the local force between the threaded rod and the receiving groove, reduce wear, and extend the service life of the threaded rod and the receiving groove. At the same time, it enhances the bearing capacity and stability of the entire embedded connection, providing a more reliable connection guarantee for the deep foundation pit support structure.

[0013] Furthermore, a prism is provided in the middle of the connecting sleeve, and the prism is driven by an external tool to drive the connecting sleeve to rotate.

[0014] The beneficial effects of adopting the above further scheme are:

[0015] The design of the prism facilitates the operation of external tools. Construction workers can use common tools (such as wrenches, etc.) to cooperate with the prism to achieve the connection or disassembly of adjacent precast concrete blocks by rotating the connecting sleeve, which improves the convenience and operability of construction. Compared with other connection methods, this method of connecting by rotating the connecting sleeve can more accurately adjust the tightness of the connection, ensure the firmness of the connection between adjacent precast concrete blocks, and can flexibly control the size of the connection force according to actual needs, which is conducive to improving the overall stability of the deep foundation pit support structure.

[0016] Furthermore, the spring is located between the fixing frame and the pressure cover, and the pressure cover clamps the pin rod through the elastic force of the spring.

[0017] The beneficial effects of adopting the above further scheme are:

[0018] The elastic force of the spring is used to clamp the pin rod with the gland, providing an automatic clamping mechanism, reducing the manual intervention link, reducing the complexity and labor intensity of the construction operation. The elastic force of the spring can make the clamping effect more stable and lasting. When subjected to a certain degree of vibration or external force interference, it can automatically adapt and adjust the clamping force to prevent the pin rod from accidentally coming out of the socket, thereby ensuring that the locking function of the locking piece is always in a reliable state, ensuring the connection firmness between the fixing frames of adjacent concrete prefabricated blocks, and enhancing the reliability of the deep foundation pit support structure under complex working conditions.

[0019] Furthermore, when the gland is engaged with the pin rod, the spring pushes the pin rod through the elastic force of the spring, thereby locking and fixing the fixing frames of the two prefabricated concrete blocks with the insertion rod.

[0020] The beneficial effects of adopting the above further scheme are:

[0021] This design uses the elastic potential energy of the spring to transform into a thrust on the pin rod, firmly locking the rod in the corresponding position, realizing the self-locking function of the locking piece, avoiding the problem of loose connection caused by long-term use or external environmental factors, and improving the safety of the deep foundation pit support structure. The continuous elastic force of the spring ensures the stability of the connection. Even when subjected to dynamic loads or slight deformation, the pin rod can remain locked to the rod, preventing connection failure, ensuring the integrity and stability of the entire deep foundation pit support structure, and avoiding a chain reaction caused by local connection failure, which endangers the safety of the deep foundation pit.

[0022] Furthermore, steel bars are preset in the prefabricated concrete block, and the through holes are located in the gaps between the steel bars, and the embedded connectors penetrate the gaps between the steel bars through the through holes.

[0023] The beneficial effects of adopting the above further scheme are:

[0024] The steel bars preset in the concrete precast block can significantly enhance its own mechanical properties, such as tensile, compressive and shear resistance, and improve the bearing capacity of the concrete precast block, so that it can better withstand various loads around the deep foundation pit. The embedded connector runs through the gaps between the steel bars, so that the embedded connector and the steel bars form an organic whole structure. The two cooperate with each other and bear the force synergistically, realizing the optimal combination of different materials and components, jointly undertaking the task of deep foundation pit support, improving the bearing capacity and stability of the entire support structure, and ensuring the safety of the deep foundation pit during construction and use.

[0025] Furthermore, the fixing holes are evenly distributed on the fixing frame, and the locking members are evenly distributed on the prefabricated concrete blocks through the fixing frame.

[0026] The beneficial effects of adopting the above further scheme are:

[0027] The evenly distributed fixing holes and locking parts ensure that the connection force between adjacent concrete precast blocks is evenly distributed, avoiding the phenomenon of local stress concentration, making the force of the entire deep foundation pit support structure more even, and improving the bearing capacity and anti-deformation ability of the structure. This evenly distributed design allows each locking part to fully play its connection and bearing role, enhances the integrity and stability of the structure, reduces the risk of overall structural collapse due to local connection failure, improves the reliability and safety of the deep foundation pit support structure, and provides a strong guarantee for the stable and safe construction of the deep foundation pit.

[0028] A method for dismantling deep foundation pit support, comprising the following steps:

[0029] S1: Before starting the demolition operation, conduct a detailed inspection and assessment of the deep foundation pit and the surrounding environment; use geological survey equipment, such as geological radar and total station, to detect the geological conditions around the deep foundation pit, including the physical and mechanical properties of the soil, such as the density, moisture content, and shear strength of the soil, and analyze the stability of the surrounding soil in combination with the previous geological survey report and monitoring data; for areas where there may be a risk of collapse, set up corresponding temporary support structures according to the risk level, such as steel support and wooden pile support. The design and construction of these temporary support structures should comply with relevant structural design specifications and safety standards, and be able to withstand the expected soil pressure to prevent safety accidents such as instability or collapse of the surrounding soil caused by the removal of the support structure; at the same time, use water level gauges and other equipment to check the water accumulation in the deep foundation pit. If there is water accumulation, select appropriate drainage methods and drainage equipment, such as small water pumps or large drainage pumps and drainage pipes, according to the depth and amount of water accumulation, to carry out drainage treatment, ensure a reasonable drainage speed, and avoid seepage damage to the surrounding soil or other safety hazards caused by poor drainage due to excessive drainage;

[0030] S2: First, remove the locking parts in the deep foundation pit support structure; when removing each locking part, first find the pressure cap on its end cover, use appropriate tools, such as a pressure rod or manual operation, press the pressure cap to overcome the elastic force of the spring and move along the axial direction of the plug rod; this operation must be performed carefully to ensure that the force is evenly applied to avoid damage to the pressure cap or spring due to excessive local force; during the movement of the pressure cap, its clamping effect on the pin rod will gradually weaken. When the clamping effect disappears, the pin rod is smoothly pulled out from the insertion hole of the plug rod; the pull-out direction of the pin rod should be along its axial direction, and the pin rod should be prevented from bending or breaking during the operation;

[0031] S3: Then, the insertion rod is pulled out from the fixing hole of the fixing frame along its axial direction to complete the removal of the single locking member; during the removal process, care should be taken to properly store the components of the removed locking member to prevent loss or damage; for all locking members, according to the above operation sequence, they are removed from the fixing frame of the concrete precast block in turn to release the partial connection relationship between adjacent concrete precast blocks; when removing multiple locking members, the operation can be performed in groups or zones to ensure the orderliness and systematicness of the removal work;

[0032] S4: After the locking parts are removed, start to remove the embedded connectors; first pull the concrete precast blocks to be removed in the opposite direction to expose the connecting sleeves between the concrete precast blocks, and then use external tools to operate the connecting sleeves; according to the shape and size of the prism in the middle of the connecting sleeve, select a suitable tool, such as a wrench or a special prism rotation tool, and tightly match the tool with the prism to apply reverse torque to rotate the connecting sleeve in the opposite direction; during the rotation process, gradually adjust the torque according to the tightness of the connection between the connecting sleeve and the threaded rod to achieve uniform and stable loosening of the connecting sleeve and avoid damage to the connecting sleeve or the threaded rod due to excessive torque; this step is to release the connection between adjacent concrete precast blocks established by the threaded rod and the connecting sleeve, so that the connection force between them is gradually reduced, and prepare for the subsequent removal of the concrete precast blocks;

[0033] S5: After the removal of the above-mentioned connecting parts, use lifting equipment or other suitable tools to remove the precast concrete blocks. When selecting lifting equipment, select equipment with sufficient load-bearing capacity and suitable working radius, such as cranes or forklifts, based on the weight, size and shape of the precast concrete blocks and the environmental conditions of the construction site. Before using the lifting equipment, it is necessary to conduct a comprehensive inspection, including checking the strength of the lifting ropes, the reliability of the hooks, the operating status of the equipment, etc., to ensure that the equipment is in good working condition. Connect the lifting ropes firmly to the precast concrete blocks, and lift the precast concrete blocks slowly and steadily during the operation to prevent them from shaking, colliding or falling during the removal process, avoid damage to the completed parts of the project, and ensure construction safety. During the removal of the precast concrete blocks, a dedicated person should be assigned to direct the operation to ensure the coordination and safety of the operation.

[0034] Furthermore, during the entire demolition process, construction workers must be equipped with safety helmets that meet national standards and wear them correctly, ensuring that the straps are fastened; at the same time, they must be equipped with safety ropes. According to the depth of the deep foundation pit and the scope of construction operations, choose safety ropes of appropriate length and strength, and firmly fix them on safe and reliable anchor points; construction workers should also wear protective gloves, which should have anti-slip, wear-resistant and cut-resistant properties to protect the safety of their hands. When using tools, they must strictly follow the tool's instruction manual. For external tools and lifting equipment, check their integrity and reliability, understand their rated parameters, and do not use them beyond the rated range. For power tools, ensure that they are well grounded to prevent electric shock accidents. During the demolition operation, pay attention to the operating environment to avoid external interference with the tools, such as collision and water immersion. When using lifting equipment, ensure that its load-bearing capacity is greater than 1.5 times the weight of the concrete precast block, and arrange for a special person to command, use a unified command signal, and set up warning signs within the working range of the lifting equipment to prevent unauthorized personnel from entering.

[0035] Furthermore, the dismantled parts are sorted and recycled. For the dismantled precast concrete blocks, they are first inspected through appearance inspection and simple mechanical property tests, such as knocking and listening to determine whether there are cracks inside, and whether there is obvious damage. For precast concrete blocks without obvious damage, use high-pressure water guns or other cleaning tools to clean the dirt and debris on the surface, and then transport them to a special storage area. The storage area should be rainproof and moisture-proof for subsequent reuse. For damaged precast concrete blocks, use non-destructive testing equipment, such as ultrasonic flaw detectors, to further detect internal damage. Determine the repair plan based on the extent of damage, repair those that can be repaired, such as using concrete repair agents to fill cracks, and crush those that cannot be repaired. The crushed materials can be used as aggregate or filling materials for other projects. For the removed locking parts, threaded rods in embedded connectors, connecting sleeves and other metal parts, use detergents and tools to clean them to remove dirt and rust, apply anti-rust oil to the threaded parts of the metal parts, spray paint and other anti-corrosion treatments on the surface, and then inspect them. Those that can continue to be used will be classified and stored in a dry and ventilated environment, and those that cannot be used will be transported to legal recycling stations for recycling.

[0036] The present invention provides a deep foundation pit support and a method for its removal. It has the following beneficial effects:

[0037] Precast concrete blocks are used as the main supporting material and can be prefabricated in the factory, ensuring the quality and dimensional accuracy of the components, reducing wet operations on the construction site, which is beneficial to saving materials and protecting the environment, while also speeding up the construction progress.

[0038] The concrete prefabricated blocks are connected through the fixing holes and locking pieces on the fixing frames at both ends. The installation of adjacent prefabricated blocks only requires inserting the locking pieces into the fixing holes to achieve preliminary positioning and connection. The operation is relatively simple and can improve construction efficiency. In addition to the locking piece connection, it can also be connected through the threaded rod and connecting sleeve of the embedded connecting piece. There is a prism in the middle of the connecting sleeve, which can be driven and rotated by an external tool to achieve connection and fixation. This design makes the installation process more flexible.

[0039] The fixing holes are evenly distributed on the fixing frame, and the locking parts are also evenly distributed on the precast concrete blocks through the fixing frame, so that the connection force between adjacent precast concrete blocks is more uniform, which can effectively improve the stability of the entire support structure and better withstand the pressure around the foundation pit.

[0040] Steel bars are preset in the precast concrete blocks, and the through holes are located in the gaps between the steel bars. The embedded connectors pass through the gaps between the steel bars through the through holes. This design enables the embedded connectors and the steel bars to cooperate with each other and work together to enhance the overall strength and bearing capacity of the precast concrete blocks, thereby improving the stability of the deep foundation pit support.

[0041] Both ends of the sleeve of the embedded connector are provided with receiving grooves, in which threaded rods are movably installed, and the threaded rods are connected to limit plates and can slide in the receiving grooves. This design allows the threaded rods to flexibly adjust their positions within a certain range, which is convenient for adapting to the position deviations between different prefabricated blocks during the construction process, ensuring the accuracy and reliability of the connection. The end cover of the locking piece is provided with a plug rod, which has a socket, and the pin rod is inserted into the socket. The plug rod is covered with a pressure cap, and a spring is installed in the pressure cap. The pressure cap clamps the pin rod through the spring force, and then the plug rod locks the fixed frames of the two concrete prefabricated blocks. This design has a certain self-locking function, which can prevent the connection from loosening when subjected to external forces such as vibration, thereby improving the safety of the connection.

[0042] The various components of this deep foundation pit support are relatively independent. If a component is damaged or needs to be adjusted during use, it can be relatively easily disassembled and replaced, which is convenient for later maintenance and upkeep. After the foundation pit project is completed, the prefabricated concrete blocks and some metal connectors can be disassembled and recycled according to actual conditions, which has a certain recycling value and can reduce project costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0044] In the attached picture:

[0045] Figure 1 It is a schematic diagram of the main appearance of the present invention;

[0046] Figure 2 It is a schematic diagram of the connection state of the present invention;

[0047] Figure 3 It is a schematic diagram of the connection state through the embedded connecting piece of the present invention;

[0048] Figure 4 It is a schematic diagram of the connection state through the locking member of the present invention;

[0049] Figure 5 It is a schematic diagram of the cross-sectional structure of the locking member of the present invention.

[0050] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0051] 1. Precast concrete block; 101. Through hole; 2. Fixing frame; 201. Fixing hole; 3. Embedded connector; 301. Threaded rod; 302. Sleeve; 303. Limiting plate; 304. Receiving groove; 4. Locking piece; 401. End cover; 402. Pin rod; 403. Socket; 404. Pressure cover; 405. Spring; 406. Insert rod; 5. Connecting sleeve; 501. Prism. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] See also Figures 1 to 5 As shown, the embodiments provided by the present invention are:

[0054] Embodiment 1

[0055] A deep foundation pit support includes a concrete precast block 1, a fixing frame 2 is provided at both ends of the concrete precast block 1, a fixing hole 201 is provided on the fixing frame 2, a locking piece 4 is inserted and installed in the fixing hole 201, two adjacent concrete precast blocks 1 are locked and fixed by the locking pieces 4 on the fixing holes 201, the fixing holes 201 are evenly distributed on the fixing frame 2, and the locking pieces 4 are evenly distributed on the concrete precast blocks 1 through the fixing frame 2, the evenly distributed fixing holes 201 and the locking pieces 4 ensure that the connection force between adjacent concrete precast blocks 1 is evenly distributed, avoids the occurrence of local stress concentration, makes the force of the entire deep foundation pit support structure more even, and improves the bearing capacity and anti-deformation capacity of the structure. This evenly distributed design enables each locking piece 4 to fully play its connection and bearing role, enhances the integrity and stability of the structure, reduces the risk of overall structural collapse due to local connection failure, improves the reliability and safety of the deep foundation pit support structure, and provides a strong guarantee for the stable and safe construction of the deep foundation pit. After the concrete precast blocks 1 are spliced, they are installed in the foundation pit as supporting beams.

[0056] Embodiment 2

[0057] In order to quickly lock and fix the adjacent prefabricated concrete blocks 1, for example, Figures 1 to 5As shown, the present invention also includes: a through hole 101 is opened on the precast concrete block 1, and a pre-embedded connector 3 is installed in the through hole 101. Steel bars are preset in the precast concrete block 1, and the through hole 101 is located in the gap between the steel bars. The pre-embedded connector 3 passes through the gap between the steel bars through the through hole 101. The steel bars preset in the precast concrete block 1 can significantly enhance its own mechanical properties, such as tensile strength, compression strength and shear strength, thereby improving the bearing capacity of the precast concrete block 1, so that it can better withstand various loads around the deep foundation pit. The embedded connector 3 penetrates the gap between the steel bars, so that the embedded connector 3 and the steel bars form an organic whole structure. The two cooperate with each other and bear the force synergistically, realizing the optimal combination between different materials and components, jointly undertaking the task of deep foundation pit support, improving the bearing capacity and stability of the entire support structure, and ensuring the safety of the deep foundation pit during construction and use. The embedded connector 3 is provided with a sleeve 302, and a receiving groove 304 is provided at both ends of the sleeve 302. A threaded rod 301 is movably installed in the receiving groove 304. A limiting plate 303 is connected to the threaded rod 301. The threaded rod 301 is slidably installed in the receiving groove 304 through the limiting plate 303. The setting of the limiting plate 303 makes the sliding of the threaded rod 301 in the receiving groove 304 more stable and controllable. When the connection operation of adjacent concrete prefabricated blocks 1 is performed, the threaded rod 301 can be prevented from excessively deflecting or shaking in the receiving groove 304, ensuring the position accuracy of the threaded rod 301 during the connection process, thereby ensuring the connection accuracy between adjacent concrete prefabricated blocks 1. When subjected to external force, the limit plate 303 can share part of the force, reduce the local force between the threaded rod 301 and the receiving groove 304, reduce wear, and extend the service life of the threaded rod 301 and the receiving groove 304. At the same time, the bearing capacity and stability of the entire embedded connecting piece 3 are enhanced, providing a more reliable connection guarantee for the deep foundation pit support structure. The two adjacent precast concrete blocks 1 are connected and fixed by the threaded rod 301 and the connecting sleeve 5. A prism 501 is provided in the middle of the connecting sleeve 5. The prism 501 is driven by an external tool to drive the connecting sleeve 5 to rotate. The design of the prism 501 facilitates the operation of external tools. Construction personnel can use common tools (such as wrenches, etc.) to cooperate with the prism 501. By rotating the connecting sleeve 5, the connection or disassembly operation of adjacent precast concrete blocks 1 is realized, thereby improving the convenience and operability of construction.Compared with other connection methods, this method of connecting by rotating the connecting sleeve 5 can more accurately adjust the tightness of the connection, ensure the connection firmness between adjacent concrete prefabricated blocks 1, and can flexibly control the size of the connection force according to actual needs, which is beneficial to improving the overall stability of the deep foundation pit support structure. The locking member 4 is provided with an end cover 401, and the end cover 401 is provided with an insertion rod 406, and the insertion rod 406 is provided with a socket 403, and a pin rod 402 is inserted in the socket 403. A pressure cover 404 is sleeved on the insertion rod 406, and a spring 405 is installed in the pressure cover 404. The spring 405 is located between the fixed frame 2 and the pressure cover 404, and the pressure cover 404 is clamped with the pin rod 402 by the elastic force of the spring 405. The elastic force of the spring 405 is used to clamp the pressure cover 404 to clamp the pin rod 402, thereby providing an automatic clamping mechanism, reducing the links of manual intervention, and reducing the complexity and labor intensity of construction operations. The elastic force of the spring 405 can make the clamping effect more stable and lasting. When subjected to a certain degree of vibration or external force interference, it can automatically adapt and adjust the clamping force to prevent the pin rod 402 from accidentally falling out of the socket 403, thereby ensuring that the locking function of the locking member 4 is always in a reliable state, ensuring the firmness of the connection between the fixing frames 2 of adjacent concrete prefabricated blocks 1, and enhancing the reliability of the deep foundation pit support structure under complex working conditions. When the pressure cover 404 is clamped with the pin rod 402, the elastic force of the spring 405 causes the spring 405 to push the pin rod 402, and then the insertion rod 406 locks the fixing frames 2 of the two concrete prefabricated blocks 1. This design utilizes the elastic potential energy of the spring 405 to convert it into a thrust on the pin rod 402, and firmly locks the insertion rod 406 in the corresponding position, thereby realizing the self-locking function of the locking member 4, avoiding the problem of loose connection caused by long-term use or external environmental factors, and improving the safety of the deep foundation pit support structure. The continuous elastic force of spring 405 ensures the stability of the connection. Even when subjected to dynamic load or slight deformation, it can keep the pin rod 402 locked to the plug rod 406, preventing the connection from failing. This ensures the integrity and stability of the entire deep foundation pit support structure and avoids chain reactions caused by local connection failure, which would endanger the safety of the deep foundation pit.

[0058] Working principle:

[0059] The deep foundation pit support adopts concrete precast blocks 1 as the main structural unit. During construction, multiple concrete precast blocks 1 are spliced ​​together to form a supporting beam and installed in the foundation pit. A through hole 101 is provided on the concrete precast block 1, and embedded connectors 3 are installed in the through hole 101. These embedded connectors 3 pass through the through hole 101, and the through hole 101 is located in the gap between the steel bars in the concrete precast block 1. The embedded connector 3 is provided with a sleeve 302, and a receiving groove 304 is provided at both ends of the sleeve 302. A threaded rod 301 is movably installed in the receiving groove 304. A limiting plate 303 is connected to the threaded rod 301, and the threaded rod 301 can slide in the receiving groove 304 through the limiting plate 303. When two adjacent concrete precast blocks 1 are connected, the threaded rod 301 and the connecting sleeve 5 play an important role. The prism 501 in the middle of the connecting sleeve 5 is driven by an external tool to drive the connecting sleeve 5 to rotate, so that the two adjacent concrete precast blocks 1 are further connected and fixed. Such a design enables the connecting components in different directions to work together, thus increasing the firmness of the connection and the integrity of the structure.

[0060] Afterwards, two adjacent precast concrete blocks 1 are locked and fixed through the fixing holes 201 on the fixing frame 2 and the locking members 4 inserted therein. The fixing holes 201 are evenly distributed on the fixing frame 2, ensuring the even distribution of the locking members 4 on the precast concrete blocks 1. Such a distribution makes the connection force between adjacent precast concrete blocks 1 more evenly distributed, thereby forming a stable overall structure. Multiple evenly distributed locking members 4 work together to tightly connect adjacent precast concrete blocks 1, so that they can withstand the pressure from the soil around the foundation pit and other external forces, and play a role in supporting and protecting the foundation pit.

[0061] The locking member 4 is provided with an end cover 401, on which an insertion rod 406 is provided, on which an insertion hole 403 is provided, in which a pin 402 is inserted, and on which a gland 404 is sleeved, in which a spring 405 is installed, and the spring 405 is located between the fixing frame 2 and the gland 404. When the insertion rod 406 is inserted into the corresponding connection part, the elastic force of the spring 405 pushes the gland 404, so that the gland 404 clamps the pin 402. In this state, the elastic force of the spring 405 firmly holds the pin 402 in the insertion hole 403, thereby locking the insertion rod 406, and realizing the locking and fixing of the fixing frames 2 of the two prefabricated concrete blocks 1. At the same time, this design also has a certain anti-loosening function. Even if it is subject to certain external force interference or vibration, due to the elastic force of the spring 405, it can ensure that the connection between the plug rod 406 and the pin rod 402 will not loosen easily, thereby ensuring the connection reliability of the entire deep foundation pit support structure, avoiding structural instability due to loose connection, and providing protection for the safety protection of the deep foundation pit.

[0062] When the deep foundation pit is subjected to external forces such as soil pressure and groundwater pressure from the surrounding soil, these external forces are first transmitted to the precast concrete blocks 1. Since the precast concrete blocks 1 are pre-installed with steel bars, their compression and deformation resistance can be enhanced. At the same time, the adjacent precast concrete blocks 1 are tightly connected through the locking pieces 4, the embedded connectors 3 and the connecting sleeves 5, so that the external forces can be evenly distributed and transmitted in the entire support structure. Through the coordinated work between the precast concrete blocks 1, the steel bars, the locking pieces 4, the embedded connectors 3 and the connecting sleeves 5, the external forces are transmitted and dispersed to the entire support structure, and finally the forces are transmitted to the supporting foundation at the bottom of the foundation pit and the surrounding stable strata, preventing the foundation pit from collapsing and ensuring the stability and safety of the deep foundation pit.

[0063] Embodiment 3

[0064] A method for dismantling deep foundation pit support, comprising the following steps:

[0065] S1: Before starting the demolition operation, conduct a detailed inspection and assessment of the deep foundation pit and the surrounding environment; use geological survey equipment, such as geological radar and total station, to detect the geological conditions around the deep foundation pit, including the physical and mechanical properties of the soil, such as the density, moisture content, and shear strength of the soil, and analyze the stability of the surrounding soil in combination with the previous geological survey report and monitoring data; for areas where there may be a risk of collapse, set up corresponding temporary support structures according to the risk level, such as steel support and wooden pile support. The design and construction of these temporary support structures should comply with relevant structural design specifications and safety standards, and be able to withstand the expected soil pressure to prevent safety accidents such as instability or collapse of the surrounding soil caused by the removal of the support structure; at the same time, use water level gauges and other equipment to check the water accumulation in the deep foundation pit. If there is water accumulation, select appropriate drainage methods and drainage equipment, such as small water pumps or large drainage pumps and drainage pipes, according to the depth and amount of water accumulation, to carry out drainage treatment, ensure that the drainage speed is reasonable, and avoid seepage damage to the surrounding soil or other safety hazards caused by poor drainage due to excessive drainage;

[0066] S2: First, remove the locking parts in the deep foundation pit support structure; when removing each locking part, first find the pressure cap on its end cover, use appropriate tools, such as a pressure rod or manual operation, press the pressure cap to overcome the elastic force of the spring and move along the axial direction of the plug rod; this operation must be performed carefully to ensure that the force is evenly applied to avoid damage to the pressure cap or spring due to excessive local force; during the movement of the pressure cap, its clamping effect on the pin rod will gradually weaken. When the clamping effect disappears, the pin rod is smoothly pulled out from the insertion hole of the plug rod; the pull-out direction of the pin rod should be along its axial direction, and the pin rod should be prevented from bending or breaking during the operation;

[0067] S3: Then, the insertion rod is pulled out from the fixing hole of the fixing frame along its axial direction to complete the removal of the single locking member; during the removal process, care should be taken to properly store the components of the removed locking member to prevent loss or damage; for all locking members, according to the above operation sequence, they are removed from the fixing frame of the concrete precast block in turn to release the partial connection relationship between adjacent concrete precast blocks; when removing multiple locking members, the operation can be performed in groups or zones to ensure the orderliness and systematicness of the removal work;

[0068] S4: After the locking parts are removed, start to remove the embedded connectors; first pull the concrete precast blocks to be removed in the opposite direction to expose the connecting sleeves between the concrete precast blocks, and then use external tools to operate the connecting sleeves; according to the shape and size of the prism in the middle of the connecting sleeve, select a suitable tool, such as a wrench or a special prism rotation tool, and tightly match the tool with the prism to apply reverse torque to rotate the connecting sleeve in the opposite direction; during the rotation process, gradually adjust the torque according to the tightness of the connection between the connecting sleeve and the threaded rod to achieve uniform and stable loosening of the connecting sleeve and avoid damage to the connecting sleeve or the threaded rod due to excessive torque; this step is to release the connection between adjacent concrete precast blocks established by the threaded rod and the connecting sleeve, so that the connection force between them is gradually reduced, and prepare for the subsequent removal of the concrete precast blocks;

[0069] S5: After the removal of the above-mentioned connecting parts, use lifting equipment or other suitable tools to remove the precast concrete blocks. When selecting lifting equipment, select equipment with sufficient load-bearing capacity and suitable working radius, such as cranes or forklifts, based on the weight, size and shape of the precast concrete blocks and the environmental conditions of the construction site. Before using the lifting equipment, it is necessary to conduct a comprehensive inspection, including checking the strength of the lifting ropes, the reliability of the hooks, the operating status of the equipment, etc., to ensure that the equipment is in good working condition. Connect the lifting ropes firmly to the precast concrete blocks, and lift the precast concrete blocks slowly and steadily during the operation to prevent them from shaking, colliding or falling during the removal process, avoid damage to the completed parts of the project, and ensure construction safety. During the removal of the precast concrete blocks, a dedicated person should be assigned to direct the operation to ensure the coordination and safety of the operation.

[0070] During the entire demolition process, construction workers must be equipped with safety helmets that meet national standards and wear them correctly, ensuring that the straps are fastened; at the same time, they must be equipped with safety ropes. According to the depth of the deep foundation pit and the scope of construction operations, choose safety ropes of appropriate length and strength, and firmly fix them on safe and reliable anchor points; construction workers should also wear protective gloves, which should have anti-slip, wear-resistant and cut-resistant properties to protect the safety of the hands. When using tools, they must strictly follow the tool's instruction manual. For external tools and lifting equipment, check their integrity and reliability, understand their rated parameters, and do not use them beyond the rated range. For power tools, ensure that they are well grounded to prevent electric shock accidents. During the demolition operation, pay attention to the operating environment to avoid external interference with the tools, such as collision and water immersion. When using lifting equipment, ensure that its load-bearing capacity is greater than 1.5 times the weight of the concrete precast block, and arrange for a special person to command, use a unified command signal, and set up warning signs within the working range of the lifting equipment to prevent unauthorized personnel from entering.

[0071] The dismantled parts shall be sorted and recycled. For the dismantled precast concrete blocks, they shall be inspected first, and the appearance shall be inspected and simple mechanical properties shall be tested, such as knocking and listening to determine whether there are cracks inside, and whether there is obvious damage. For the precast concrete blocks without obvious damage, high-pressure water guns or other cleaning tools shall be used to clean the dirt and debris on the surface, and then the blocks shall be transported to a special storage area. The storage area shall be rainproof and moisture-proof for subsequent reuse. For the damaged precast concrete blocks, non-destructive testing equipment, such as ultrasonic flaw detectors, shall be used to further detect internal damage. The degree of damage determines the repair plan. Repair those that can be repaired, such as filling cracks with concrete repair agents. Those that cannot be repaired should be crushed and the crushed materials can be used as aggregate or filling materials for other projects. For the removed locking parts, threaded rods in embedded connectors, connecting sleeves and other metal parts, use detergents and tools to clean them to remove dirt and rust. Apply anti-rust oil to the threaded parts of the metal parts, spray paint on the surface and other anti-corrosion treatments, then inspect them, and classify and store those that can continue to be used in a dry and ventilated environment. Transport unusable ones to legal recycling stations for recycling.

[0072] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0073] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A deep foundation pit support, comprising a precast concrete block (1), wherein both ends of the precast concrete block (1) are provided with a fixing frame (2), wherein the fixing frame (2) is provided with a fixing hole (201), wherein a locking member (4) is inserted and installed in the fixing hole (201), wherein two adjacent precast concrete blocks (1) are locked and fixed by the locking members (4) on the fixing holes (201), wherein the precast concrete blocks (1) are installed in the foundation pit as a supporting beam after being spliced, and wherein the precast concrete blocks (1) are characterized in that: The prefabricated concrete block (1) is provided with a through hole (101), a pre-embedded connector (3) is installed in the through hole (101), the pre-embedded connector (3) is provided with a sleeve (302), both ends of the sleeve (302) are provided with a receiving groove (304), a threaded rod (301) is movably installed in the receiving groove (304), and two adjacent prefabricated concrete blocks (1) are connected and fixed by the threaded rod (301) and the connecting sleeve (5); The locking member (4) is provided with an end cover (401), the end cover (401) is provided with an insertion rod (406), the insertion rod (406) is provided with an insertion hole (403), a pin rod (402) is inserted into the insertion hole (403), the insertion rod (406) is sleeved with a pressure cover (404), and a spring (405) is installed in the pressure cover (404).

2. A deep foundation pit support according to claim 1, characterized in that: The threaded rod (301) is connected to a limiting plate (303), and the threaded rod (301) is slidably installed in the receiving groove (304) via the limiting plate (303).

3. A deep foundation pit support according to claim 1, characterized in that: A prism (501) is provided in the middle of the connecting sleeve (5), and the prism (501) is driven by an external tool to drive the connecting sleeve (5) to rotate.

4. The deep foundation pit support according to claim 1, characterized in that: The spring (405) is located between the fixed frame (2) and the pressure cover (404), and the pressure cover (404) clamps the pin rod (402) through the elastic force of the spring (405).

5. The deep foundation pit support according to claim 1, characterized in that: When the pressure cover (404) is engaged with the pin rod (402), the spring (405) pushes the pin rod (402) through the elastic force of the spring (405), thereby locking and fixing the fixing frames (2) of the two prefabricated concrete blocks (1) with the insertion rod (406).

6. The deep foundation pit support according to claim 1, characterized in that: Steel bars are preset in the prefabricated concrete block (1), and the through hole (101) is located in the gap between the steel bars. The embedded connection piece (3) passes through the gap between the steel bars through the through hole (101).

7. The deep foundation pit support according to claim 1, characterized in that: The fixing holes (201) are evenly distributed on the fixing frame (2), and the locking members (4) are evenly distributed on the prefabricated concrete blocks (1) through the fixing frame (2).

8. A method for dismantling a deep foundation pit support as claimed in claim 1, characterized in that: The following steps are involved: S1: Before starting the demolition operation, conduct a detailed inspection and assessment of the deep foundation pit and the surrounding environment; use geological survey equipment, such as geological radar and total station, to detect the geological conditions around the deep foundation pit, including the physical and mechanical properties of the soil, such as the density, moisture content, and shear strength of the soil, and analyze the stability of the surrounding soil in combination with the previous geological survey report and monitoring data; For areas where there may be a risk of collapse, corresponding temporary support structures, such as steel support and wooden pile support, shall be set up according to the degree of risk. The design and construction of these temporary support structures shall comply with relevant structural design specifications and safety standards, and be able to withstand the expected soil pressure to prevent safety accidents such as instability or collapse of the surrounding soil caused by the removal of the support structure. At the same time, use water level gauges and other equipment to check the water accumulation in the deep foundation pit. If there is water accumulation, select appropriate drainage methods and drainage equipment, such as small water pumps or large drainage pumps and drainage pipes, according to the depth and amount of water accumulation, to carry out drainage treatment, ensure a reasonable drainage speed, and avoid seepage damage to the surrounding soil due to excessive drainage or other safety hazards caused by poor drainage. S2: First, the locking members (4) in the deep foundation pit support structure are removed; when removing each locking member (4), first find the pressure cover (404) on its end cover (401), use an appropriate tool, such as a pressure rod or manual operation, press the pressure cover (404) to overcome the elastic force of the spring (405) and move along the axial direction of the insertion rod (406); this operation must be performed carefully to ensure that the force is applied evenly to avoid damage to the pressure cover (404) or the spring (405) due to excessive local force; during the movement of the pressure cover (404), its clamping effect on the pin rod (402) will gradually weaken, and when the clamping effect disappears, the pin rod (402) is smoothly pulled out from the insertion hole (403) of the insertion rod (406); the pulling direction of the pin rod (402) should be along its axial direction, and the pin rod (402) should be prevented from bending or breaking during the operation; S3: Subsequently, the insertion rod (406) is pulled out from the fixing hole (201) of the fixing frame (2) along its axial direction to complete the removal of the single locking member (4); during the removal process, care should be taken to properly store the components of the removed locking member (4) to prevent loss or damage; for all locking members (4), they are removed from the fixing frame (2) of the concrete prefabricated block (1) in turn according to the above-mentioned operation sequence to release the partial connection relationship between adjacent concrete prefabricated blocks (1); when removing multiple locking members (4), the operation can be performed in groups or zones to ensure the orderliness and systematicness of the removal work; S4: After the locking member (4) is removed, the embedded connecting member (3) is removed; first, the prefabricated concrete block (1) to be removed is pulled in the opposite direction to expose the connecting sleeve (5) between the prefabricated concrete blocks (1), and then the connecting sleeve (5) is operated using an external tool; according to the shape and size of the middle prism (501) of the connecting sleeve (5), a suitable tool, such as a wrench or a special prism rotating tool, is selected, the tool is tightly matched with the prism (501), and a reverse torque is applied to make the connecting sleeve (5) rotate in the opposite direction; During the rotation process, the torque is gradually adjusted according to the tightness of the connection between the connecting sleeve (5) and the threaded rod (301) to achieve uniform and stable loosening of the connecting sleeve (5) and avoid damage to the connecting sleeve (5) or the threaded rod (301) due to excessive torque. This step is intended to release the connection between adjacent prefabricated concrete blocks (1) established through the threaded rod (301) and the connecting sleeve (5), so that the connection force between them is gradually reduced, thereby preparing for the subsequent removal of the prefabricated concrete blocks (1). S5: After the removal of the above-mentioned connecting parts, use lifting equipment or other suitable tools to remove the precast concrete block (1); when selecting the lifting equipment, according to the weight, size and shape of the precast concrete block (1) and the environmental conditions of the construction site, select equipment with sufficient load-bearing capacity and suitable working radius, such as a crane or forklift; before using the lifting equipment, it is necessary to conduct a comprehensive inspection, including checking the strength of the lifting rope, the reliability of the hook, the operating condition of the equipment, etc., to ensure that the equipment is in good working condition; the lifting rope is firmly connected to the precast concrete block (1), and the precast concrete block (1) is lifted slowly and steadily during the operation to prevent it from shaking, colliding or falling during the removal process, avoiding damage to the completed part of the project, and ensuring construction safety; during the removal of the precast concrete block (1), a dedicated person should be assigned to direct the operation to ensure the coordination and safety of the operation.

9. A method for dismantling deep foundation pit support according to claim 8, characterized in that: During the entire demolition process, construction workers must be equipped with safety helmets that meet national standards and wear them correctly, ensuring that the straps are fastened. At the same time, they must be equipped with safety ropes. According to the depth of the deep foundation pit and the scope of construction operations, the safety ropes of appropriate length and strength should be selected and firmly fixed to safe and reliable anchor points. Construction workers should also wear protective gloves, which should have anti-slip, wear-resistant and cut-resistant properties to protect the safety of their hands. When using tools, they must strictly follow the tool manual. For external tools and lifting equipment, their integrity and reliability must be checked, and their rated parameters must be understood. They must not be used beyond the rated range. For electric tools, ensure that they are well grounded to prevent electric shock accidents. During the demolition operation, pay attention to the operating environment to avoid external interference with the tools, such as collision and water immersion. When using lifting equipment, ensure that its load-bearing capacity is greater than 1.5 times the weight of the concrete precast block (1), and arrange for a dedicated person to command and use unified command signals. Set up warning signs within the working range of the lifting equipment to prevent unauthorized personnel from entering.

10. A method for dismantling deep foundation pit support according to claim 8, characterized in that: The removed parts are sorted and recycled. For the removed precast concrete blocks (1), they are first inspected through appearance inspection and simple mechanical property tests, such as knocking and listening to determine whether there are cracks inside, and whether there is obvious damage. For the precast concrete blocks (1) without obvious damage, use a high-pressure water gun or other cleaning tools to clean the dirt and debris on the surface, and then transport them to a special storage area. The storage area should be rainproof and moisture-proof for subsequent reuse. For the damaged precast concrete blocks (1), use non-destructive testing equipment, such as an ultrasonic flaw detector, to further detect internal damage. According to the degree of damage, Determine the repair plan, repair those that can be repaired, such as using concrete repair agent to fill cracks, and crush those that cannot be repaired. The crushed materials can be used as aggregates or filling materials for other projects. For the removed locking parts (4), the threaded rods (301) in the embedded connecting parts (3), the connecting sleeves (5) and other metal parts, use detergents and tools to clean them to remove dirt and rust. Apply anti-rust oil to the threaded parts of the metal parts, spray paint on the surface and other anti-corrosion treatments, and then inspect them. The parts that can continue to be used are classified and stored in a dry and ventilated environment, and the unusable parts are transported to legal recycling stations for recycling.

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