An assembled prestressing device for foundation pit steel support structure

Abstract

The present invention is an assembled prestressing device for a foundation pit steel support structure, which relates to the field of construction engineering, and includes a main connecting body, a secondary connecting body, a sliding tooth plate meshing locking assembly, and a jack. The main and secondary connecting bodies are combined into an integrated device, and the two can only undergo relative displacement along the direction of applying prestress. The jack is used to press the secondary connecting body and the main connecting body against each other to apply prestress. The main connecting body is provided with a middle sliding tooth plate, and the secondary connecting body is provided with an end sliding tooth plate. The two tooth plates form a sliding tooth plate meshing locking assembly, which meshes with each other to achieve the locking of the relative position between the main connecting body and the secondary connecting body after applying prestress, thereby providing prestress to the steel support structure. The structural components of the present invention are simple in form, have sufficient rigidity and strength, are controllable in real time in prestress loading, are easy to install and disassemble, are easy to maintain and overhaul, occupy a small space, and can be reused.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit construction in building engineering, and in particular to an assembled prestressing device for a foundation pit steel support structure. Background Art

[0002] For foundation pit projects with wide excavation range, large depth and complex geological conditions, the required support system is huge and the project cost is high. In addition, during the excavation of the foundation pit, the soil at the bottom of the pit is in a state of unloading and rebounding, and the stress in the soil at the bottom of the pit is redistributed. The stress and deformation of the soil around the foundation pit will also continue to change. The traditional steel support structure system is difficult to meet the deformation requirements during the excavation of the foundation pit, and there is a loss of prestress. This has created a strong demand for assembled prestressed steel support structures that can maintain prestress. However, there are many deficiencies in the prestressing structure in the prior art, such as complex equipment, high manufacturing costs, cumbersome installation process, poor structural reliability, and difficult maintenance. Some prestressing structures cannot adjust the prestress in time when the foundation pit undergoes large deformation after being preloaded before construction, or require hydraulic cylinders to work continuously to maintain prestress, etc. The equipment and maintenance costs are high and are not suitable for large-scale use.

[0003] Therefore, it is very necessary to further design a device that can be used to apply prestress to the steel support structure of the foundation pit, which has a reliable structure, simple components, convenient loading, economy and safety, and is easy to install and maintain, so as to effectively regulate the deformation of the foundation pit retaining structure in deep and large foundation pits and complex geological conditions. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide an assembled prestressed structure device for foundation pit steel support. It is an assembled prestressed structure for foundation pit steel support that adopts a mechanical structure, has a reliable structure and simple loading. It can flexibly provide prestress and control foundation pit deformation. It is not only simple to install and maintain, and improves construction efficiency, but also reusable and can be used in conjunction with axial force monitoring to further reduce the cost of use.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an assembled prestressing device for foundation pit steel support structure, characterized in that: the assembled prestressing device includes a main connecting body, a secondary connecting body, a sliding tooth plate engagement locking assembly and a jack, which can apply prestress to external connecting structures such as steel supports, thereby optimizing the supporting effect on the enclosing structure.

[0006] The device is fixed at the support node installation position of the external steel support structure, and is connected and fixed with the external connecting parts by high-strength bolts. It includes a main connecting body and a secondary connecting body. A jack is also provided between the secondary connecting body and the main connecting body. The jack is a loading device. A hydraulic jack or other loading device can be selected. The jack is used to press the secondary connecting body and the main connecting body respectively to apply prestress. The main connecting body is provided with a middle sliding tooth plate, and the secondary connecting body is provided with an end sliding tooth plate. The two tooth plates are engaged with each other to achieve the locking of the relative position between the main connecting body and the secondary connecting body after the prestress is applied.

[0007] The main connection body is provided with a plurality of stop cylinders and stop partitions for fixing the middle sliding tooth plate. The stop cylinder is welded to the main connection body using a high-strength steel cylinder, and the middle sliding tooth plate is provided with a second waist-shaped hole matching the number of the stop cylinders. The length of the second waist-shaped hole is the same as the height of the sliding teeth on the middle sliding tooth plate, and is correspondingly mounted on the stop cylinder to limit the lateral sliding of the middle sliding tooth plate on the main connection body. The stop partition is two partitions arranged on both sides of the middle sliding tooth plate. The partition is a solid steel body with sufficient thickness, welded to the main connection body, and the partition can limit the middle sliding tooth plate to the corresponding position of the main connection body, and is used to transmit the axial load consistent with the direction of applying the prestress, and is not damaged when the axial load is transmitted.

[0008] The secondary connection body is provided with an end sliding tooth plate at a corresponding position of the middle sliding tooth plate, and the end sliding tooth plate is provided with a return stud, which is a high-strength solid steel cylinder with a thread, and is locked with a return nut after passing through the first waist-shaped hole provided on the secondary connection body. A bolt hole is provided beside the first waist-shaped hole, and a stop bolt is screwed into the bolt hole to press against the end sliding tooth plate so that the end sliding tooth plate and the middle sliding tooth plate are meshed with each other to realize the locking work of the relative position between the main connection body and the secondary connection body. When the end sliding tooth plate is completely separated from the middle sliding tooth plate, the stop cylinder just contacts the side of the tooth surface near the waist-shaped hole of the middle sliding tooth plate, and when the end sliding tooth plate is meshed with the middle sliding tooth plate, the stop cylinder just contacts the other side of the waist-shaped hole on the middle sliding tooth plate.

[0009] The central axis of the main connection body and the secondary connection body after installation is in the same straight line as the direction of the connection line of the two adjacent support nodes of the steel support structure, and a pair of end sliding tooth plates and middle sliding tooth plates with the same structure are symmetrically arranged to form a mutually meshing and locking structure. A spring assembly composed of several stainless steel springs is arranged between the two middle sliding tooth plates to achieve the mutual meshing of the sliding tooth plates and the end sliding tooth plates during loading, and to provide a rebound force to enable the middle sliding tooth plates to reciprocate laterally. A pair of stop bolts are also symmetrically arranged on both sides of the return stud, and two bolt holes are correspondingly arranged on both sides of the first waist-shaped hole on the secondary connection body.

[0010] The secondary connection body is a steel frame structure, and is provided with movable holes that limit the displacement of the main connection body. After the main connection body is inserted into the movable space, it forms an integrated device with the secondary connection body that performs relative displacement activities along the direction of applying prestress. The secondary connection body has a jack installation area at the other end of the area where the main connection body is installed. The prestress is applied by pressing one end of the jack against the inner wall of the secondary connection body connection panel and the other end against the loading support set at the end center of the main connection body. A displacement meter connecting the secondary connection body and the main connection body is provided next to the jack, and the displacement meter must have sufficient travel. During the foundation pit support process, the prestress loading can be synchronized with the displacement and axial force monitoring of the foundation pit steel support structure to flexibly load. After the loading is completed, the jack can be taken out.

[0011] The bottom of the frame of the secondary connection body is provided with a bottom plate, which is made of solid steel plate and fixed to the secondary connection body by welding or bolting. When the thickness of the end sliding tooth plate is the same as that of the middle sliding tooth plate, a support plate in contact with the bottom plate needs to be provided below the end sliding tooth plate to ensure the stable operation of the end sliding tooth plate. The surface of the secondary connection body is provided with a removable cover plate in the area where the main connection body is installed, and the removable cover plate is fixed to the frame of the secondary connection body by fixing bolts, and a cover plate with a rotating shaft is provided in the area where the jack is installed. The thickness of the middle sliding tooth plate on the main connection body is less than or equal to the distance between the contact surface with the main connection body and the removable cover plate to ensure the activity space of the middle sliding tooth plate.

[0012] The outer sides of both ends of the main connecting body and the auxiliary connecting body are connecting surfaces, which are respectively provided with a plurality of connecting bolt holes for connecting to external structures. The device adopts a main connecting body, an auxiliary connecting body, a middle sliding tooth plate and an end sliding tooth plate made of solid steel, and each surface in contact with the outside is provided with an anti-corrosion coating or other anti-corrosion measures, and each sliding contact surface in the device is smooth and coated with lubricating oil.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: it can be applied to the steel support enclosure structure of the large deformation foundation pit, the installation position is flexible, and it can be arranged at the required support node position according to the actual working conditions. After being installed at the node position or the support position of the steel support structure, it can enhance the ability to resist the deformation of the foundation pit during the construction process. At the same time, the device adopts a mechanical structure with high rigidity. It can flexibly apply prestress in combination with the deformation of the foundation pit and the axial force monitoring of the steel support, which can effectively control the deformation of the foundation pit, improve the safety and stability of the foundation pit support structure, effectively control the deformation of the surrounding soil, and reduce the environmental deformation effect of excavation on adjacent buildings (structures). The component of the present invention is simple in form, has sufficient rigidity and strength, and the prestress loading is controllable in real time. It is very convenient to install, disassemble, maintain and repair, and can be recycled, with good use and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic cross-sectional view of the prestressing device of the present invention.

[0015] Figure 2 It is a schematic diagram of the top view of the main connecting body in the present invention.

[0016] Figure 3 It is a schematic side view of the main connecting body in the present invention.

[0017] Figure 4 It is a schematic cross-sectional structural diagram of the secondary connecting body in the present invention.

[0018] Figure 5 It is a side view schematic diagram of the secondary connecting body in the present invention.

[0019] Figure 6 It is a schematic top view of the secondary connecting body in the present invention.

[0020] Figure 7 It is a schematic diagram of the structure of the middle sliding tooth plate in the present invention.

[0021] Figure 8 It is a schematic diagram of the structure of the end sliding gear plate in the present invention.

[0022] In the figure: 10, main connecting body; 11, first connecting bolt hole; 12, stop cylinder; 13, stop partition; 14, loading support; 20, secondary connecting body; 21, bolt hole; 22, first waist-shaped hole; 23, bottom plate; 24, second connecting bolt hole; 25, top plate; 26, rotating shaft; 27, cover plate; 28, fixing bolt; 29, removable cover plate; 30, middle sliding tooth plate; 31, second waist-shaped hole; 40, end sliding tooth plate; 41, return nut; 42, return stud; 50, spring assembly; 60, stop bolt; 70, displacement meter; 80, jack. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings. The present application can be implemented in a variety of different forms and is not limited to the implementation described in this embodiment. The purpose of providing the following specific embodiments is to facilitate a clearer and more thorough understanding of the technical content of the present solution, wherein the words indicating directions such as up, down, left, and right are only for the position of the structure shown in the corresponding drawings.

[0024] The present invention is an assembled prestressing structure device for foundation pit steel support, which can be flexibly installed at the steel support structure node by locking with a tooth plate, and can effectively control the deformation of the foundation pit by adjusting the size of the support prestress.

[0025] According to the attached Figure 1 ~Attached Figure 8The device of the present invention includes a main connection body 10 and a secondary connection body 20. The main connection body 10 is provided with a middle sliding tooth plate 30, and the secondary connection body 20 is provided with an end sliding tooth plate 40. The two tooth plates are engaged with each other to achieve the locking work of the relative position between the main connection body 10 and the secondary connection body 20.

[0026] The main connection body 10 is provided with a plurality of stop cylinders 12 and stop partitions 13 for fixing the middle sliding tooth plate 30. The middle sliding tooth plate 30 is provided with second waist-shaped holes 31 matching the number of the stop cylinders 12 and correspondingly mounted on the stop cylinders 12. The stop partitions 13 are two partitions arranged on both sides of the middle sliding tooth plate 30, which limit the middle sliding tooth plate 30 at the corresponding position of the main connection body 10.

[0027] The secondary connection body 20 is provided with an end sliding tooth plate 40 at a corresponding position of the middle sliding tooth plate 30. The end sliding tooth plate 40 has a return stud 42. The return stud 42 passes through the first waist-shaped hole 22 provided on the secondary connection body 20 and is locked with a return nut 41. For easy disassembly and assembly, the first waist-shaped hole 22 is a smooth through hole, and its hole diameter is larger than the rod diameter of the return stud 42 and smaller than the outer diameter of the return nut 41. A bolt hole 21 is provided beside the first waist-shaped hole 22. The stop bolt 60 is screwed into the bolt hole 21 and pressed against the end sliding tooth plate 40, so that the end sliding tooth plate 40 and the middle sliding tooth plate 30 can be meshed and locked with each other.

[0028] To ensure the smooth application of prestress, the central axis of the main connection body 10 and the secondary connection body 20 after installation is in the same straight line as the direction of the line connecting the two adjacent support nodes of the steel support structure, and a pair of end sliding tooth plates 40 and middle sliding tooth plates 30 with the same structure are symmetrically arranged on both sides, and a spring assembly 50 composed of a number of stainless steel springs is arranged between the two meshing and locking structures at the middle sliding tooth plate 30. A pair of stop bolts 60 are symmetrically arranged on both sides of the return stud 42, and two bolt holes 21 are correspondingly arranged on both sides of the first waist-shaped hole 22 on the secondary connection body 20.

[0029] In order to facilitate the disassembly, assembly and movement of the device, the secondary connection body 20 is a steel frame structure, and is provided with a movable hole position that limits the displacement of the main connection body 10. After the main connection body 10 is inserted into the movable hole, it forms an integrated device with the secondary connection body 20 that can perform relative displacement activities along the direction of applying prestress. The secondary connection body 20 has an installation area for a jack 80 at the other end of the area where the main connection body 10 is installed. The prestress is applied by pressing one end of the jack 80 against the inner wall of the secondary connection body 20 and the other end against the loading support 14 set at the center position of the end of the main connection body 10. A displacement meter 70 connecting the secondary connection body 20 and the main connection body 10 is provided next to the jack 80.

[0030] The bottom of the frame of the secondary connection body 20 is provided with a bottom plate 23, and the area on the surface where the main connection body 10 is mounted is provided with a removable cover plate 29, which is fixed to the frame of the secondary connection body 20 by fixing bolts 28. A cover plate 27 with a rotating shaft 26 is provided in the area where the jack 8 is mounted, so that it is convenient to open the cover plate 27 to disassemble and install the jack 80. To facilitate the opening and use of the cover plate 27, a handle is provided on the outer surface of the cover plate 27.

[0031] A plurality of first connection bolt holes 11 and second connection bolt holes 24 are respectively disposed on the outer connecting structural surfaces of the main connection body 10 and the auxiliary connection body 20 .

[0032] During the construction process, in the initial state of the device, the return nut 41 is tightened, the stop bolt 60 is loosened, and the end sliding tooth plate 40 and the middle sliding tooth plate 30 of the meshing locking structure are in a separated state. First, the device is connected and fixed to the part to be installed at the support node of the foundation pit retaining structure by bolts through the first connection bolt hole 11 of the main connection body 10 and the second connection bolt hole 24 of the auxiliary connection body 20. Then open the cover plate 27, install the jack 80 and the displacement meter 70 in place. Prestress is applied by the jack 80 to control a reasonable loading rate. The displacement meter 70 can be used to control the expected stroke or the axial force monitoring result of the steel support to stop loading, and then the two return nuts 41 are loosened to the top, and the stop bolt 60 is tightened at the same time, so that the end sliding tooth plate 40 and the middle sliding tooth plate 30 are in a meshing state, and the relative position of the main connection body 10 and the auxiliary connection body 20 is locked. Finally, the jack 80 is gradually unloaded. After the decompression and unloading are completed, the jack 80 can be taken out and the cover plate 27 is closed. The prestressing work of the support node at this location is completed, and then the same steps are continued for other nodes on the enclosure structure that need to be prestressed.

[0033] After the foundation pit support is completed and the device needs to be dismantled, the cover plate 27 can be opened first, and the jack 80 can be installed. The jack 80 can apply reasonable stress, which can be controlled by the displacement 70 to support the main connection body 10, and then the stop bolt 60 is loosened, and then the return nut 41 is tightened until the end sliding tooth plate 40 and the middle sliding tooth plate 30 are separated. Then the jack 80 is slowly unloaded and removed, and the cover plate 27 is closed. Finally, the bolts at the first connection bolt hole 11 on the main connection body 10 and the second connection bolt hole 24 on the secondary connection body 20 are removed, and the dismantling work of the device is completed.

[0034] It should be further explained that, unless otherwise clearly stipulated and limited, the terms such as "connect", "fixed", "set", "provided with", "installed" and the like should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0035] The above implementation modes are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering and technical personnel in the field shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An assembled prestressing device for a foundation pit steel support structure, characterized in that: The device is fixed at the support node installation position of the external steel support structure, and includes a main connection body and a secondary connection body. A jack is also provided between the secondary connection body and the main connection body. The jack is used to respectively press the secondary connection body and the main connection body to apply prestress. The main connection body is provided with a middle sliding tooth plate, and the secondary connection body is provided with an end sliding tooth plate. The two tooth plates are engaged with each other to achieve the locking work of the relative position between the main connection body and the secondary connection body after the prestress is applied. The main connecting body is provided with a plurality of stop cylinders and stop partitions for fixing the middle sliding tooth plate, the middle sliding tooth plate is provided with a second waist-shaped hole matching the number of the stop cylinders, and is correspondingly mounted on the stop cylinder to limit the lateral sliding of the middle sliding tooth plate on the main connecting body, the stop partition is two partitions arranged on both sides of the middle sliding tooth plate, which limit the middle sliding tooth plate at the corresponding position of the main connecting body and are used to transmit axial loads consistent with the direction of applying prestress, the secondary connecting body is provided with an end sliding tooth plate at the corresponding position of the middle sliding tooth plate, the end sliding tooth plate is provided with a return stud, which is locked with a return nut after passing through the first waist-shaped hole provided on the secondary connecting body, a bolt hole is provided beside the first waist-shaped hole, the stop bolt is screwed into the bolt hole to press against the end sliding tooth plate so that the end sliding tooth plate and the middle sliding tooth plate are meshed with each other to achieve the locking work of the relative position between the main connecting body and the secondary connecting body, The secondary connection body is a steel frame structure, provided with a movable hole position that limits the displacement of the main connection body. After the main connection body is inserted into the movable hole position, it forms an integrated device with the secondary connection body that performs relative displacement activities along the direction of applying prestress. The secondary connection body has a jack installation area at the other end of the area where the main connection body is installed. The prestress is applied by pressing one end of the jack against the inner wall of the connection panel of the secondary connection body and the other end against the loading support set at the center position of the end of the main connection body. A displacement meter connecting the secondary connection body and the main connection body is provided beside the jack. A bottom plate is provided at the bottom of the frame of the secondary connection body, and a detachable cover plate is provided at the top area of ​​the sliding tooth plate structure on the left side of the secondary connection body. The detachable cover plate is fixed to the frame of the secondary connection body by fixing bolts, and a cover plate with a rotating shaft is provided in the installation area of ​​the jack on the right side of the secondary connection body. The outer side surfaces of the main connecting body and the auxiliary connecting body are connecting surfaces for connecting to external structures, and are respectively provided with a plurality of connecting bolt holes.

2. The assembled prestressing device for foundation pit steel support structure according to claim 1 is characterized in that: The central axis of the main connection body and the auxiliary connection body after installation is in the same straight line as the direction of the connection line of two adjacent support nodes of the steel support structure, and a pair of end sliding tooth plates and middle sliding tooth plates with the same structure are symmetrically arranged on both sides to form a mutually meshing and locking structure. A spring assembly composed of a number of stainless steel springs is provided at the middle sliding tooth plate between the two meshing and locking structures. The middle sliding tooth plate is provided with a rebound force provided by the spring assembly to move laterally. A pair of stop bolts are also symmetrically arranged on both sides of the return stud, and two bolt holes are correspondingly arranged on both sides of the first waist-shaped hole on the auxiliary connection body.

3. The assembled prestressing device for foundation pit steel support structure according to claim 1 is characterized in that: The assembled prestressing device adopts a main connecting body, a secondary connecting body, a middle sliding tooth plate and an end sliding tooth plate made of solid steel. All surfaces in contact with the outside are provided with an anti-corrosion coating. The sliding contact surfaces in the assembled prestressing device are smooth and coated with lubricating oil.

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