Foundation pit steel support system based on axial force loading device

Abstract

The invention discloses an axial force loading device-based foundation pit steel support system, which comprises a steel support structure and an end axial force loading device, and is characterized in that the steel support structure comprises two groups of end fixing devices, a plurality of steel pipes and a middle connecting assembly, the two groups of end fixing devices are fixed on two underground diaphragm walls, and the two groups of end fixing devices are fixed on the two underground diaphragm walls; the central axes of the two sets of end fixing devices are overlapped, every two adjacent steel pipes are connected through a middle connecting assembly, and the steel pipes at the two ends are connected with the end fixing devices. The end axial force loading device is installed in the end fixing device and applies an axial load to the steel pipe. Accurate control, uniform distribution and intelligent monitoring and adjusting functions of axial loads are achieved in an electromagnetic loading mode, and the defects that a traditional foundation pit steel supporting structure is insufficient in loading mode accuracy, complex in disassembly and the like are overcome.

Description

Technical Field

[0001] The present invention belongs to the application field of foundation pit support engineering, and in particular relates to a foundation pit steel support system based on an axial force loading device. Background Art

[0002] In the field of foundation pit construction, the steel support system is a key component of underground continuous wall support, and its main function is to ensure the stability of the foundation pit. However, the traditional steel support system has the following obvious shortcomings. (1) Most existing steel support systems use mechanical loading devices, such as hydraulic jacks and bolt tightening, to load axial forces. However, these methods are difficult to accurately control the loading force, which can easily lead to insufficient or excessive support force, thereby affecting the stability of the foundation pit. (2) The load transfer of steel support devices often relies on simple mechanical connections or clamping devices, which may lead to uneven load distribution, especially at structural joints and at the connection between steel pipes and fixing devices. Stress concentration is easy to occur, increasing the risk of damage in local areas, and may even cause failure or fracture of steel supports, affecting the overall performance of the support system. (3) The structural connections of traditional steel support systems usually use welding or bolt connections. Although these methods are reliable in strength, the installation and disassembly process is complicated and time-consuming, which prolongs the construction period and increases the project cost.

[0003] Therefore, there is an urgent need to develop a new type of steel support system that can achieve precise load control, uniform load distribution, and have intelligent monitoring and adjustment functions to improve the safety, economy and durability of the foundation pit support system. Summary of the invention

[0004] Based on the above-mentioned problems of the prior art, the present invention provides a foundation pit steel support system based on an axial force loading device, which adopts electromagnetic loading to achieve precise control, uniform distribution and intelligent monitoring and adjustment functions of the axial load, thereby overcoming the shortcomings of traditional foundation pit steel support structures such as insufficient loading accuracy and complex disassembly.

[0005] The main technical solutions adopted in the present invention are: A foundation pit steel support system based on an axial force loading device comprises a steel support structure and an end axial force loading device, wherein: The steel support structure includes two groups of end fixtures, a plurality of steel pipes and an intermediate connection assembly. The two groups of end fixtures are fixed on two underground continuous walls, and the central axes of the two groups of end fixtures overlap. The adjacent steel pipes are connected by an intermediate connection assembly, and the steel pipes at both ends are connected to the end fixtures. The end axial force loading device is installed in the end head fixing device to apply axial load to the steel pipe.

[0006] Preferably, the end fixing device is a hollow cylinder, and the interior of the hollow cylinder is used to install the end axial force loading device and the connecting steel pipe.

[0007] Preferably, the intermediate connection assembly is a slot structure for clamping and installing the steel pipe.

[0008] Preferably, the intermediate connecting component includes an upper clamping groove part and a lower clamping groove part, and the upper clamping groove part and the lower clamping groove part are connected by a sliding rod. The clamping grooves of the upper clamping groove part and the lower clamping groove part cooperate to form a circular cavity for clamping the steel pipe. A force transmission component is arranged in the circular cavity for evenly transmitting the pressure of the steel pipe.

[0009] Preferably, the force transmission assembly includes two force transmission plates, and the two force transmission plates are connected in a circumferential sealing manner using rubber to form a cavity I for injecting a force transmission medium.

[0010] Preferably, the end axial force loading device includes an electromagnetic block I, an electromagnetic block II, a coil I, a coil II and two pads, the electromagnetic block I and the electromagnetic block II are both arranged in the end fixing device, and the electromagnetic block II is located on the side close to the underground continuous wall, the coil I and the coil II are respectively arranged corresponding to the electromagnetic block I and the electromagnetic block II, so that the electromagnetic block I and the electromagnetic block II repel each other, the electromagnetic block II cooperates with the end fixing device to form a cavity II for injecting a force transmission medium, and the end fixing device is provided with an injection hole, which is connected to the cavity II, and pads are provided between the cavity II and the end fixing device and between the electromagnetic block I and the steel pipe.

[0011] Preferably, it also includes a plurality of intermediate axial force loading devices, each of which is correspondingly arranged on the corbel of the supporting column to perform multi-level axial force loading on the steel support system.

[0012] Preferably, the intermediate axial force loading device includes an intermediate electromagnetic block I, an intermediate electromagnetic block II, an intermediate coil I, an intermediate coil II, two intermediate pads and a circular sleeve, the circular sleeves respectively fix the steel pipes on both sides, the ends of the steel pipes on both sides are respectively contacted and connected with one side of the intermediate pad, the intermediate coil I and the intermediate coil II are respectively arranged corresponding to the intermediate electromagnetic block I and the intermediate electromagnetic block II, so that the intermediate electromagnetic block I and the intermediate electromagnetic block II repel each other, and the intermediate pads cooperate with the intermediate electromagnetic block I and the intermediate electromagnetic block II to form a cavity III for injecting force transmission medium.

[0013] Preferably, a pressure sensor I is arranged in cavity II in the end axial force loading device, pressure sensor II is arranged on both coil I and coil II, a pressure sensor III is arranged in cavity III of the intermediate axial force loading device, pressure sensor IV is arranged on both intermediate coil I and intermediate coil II, and pressure sensor I, pressure sensor II, pressure sensor III and pressure sensor IV are all connected to the monitoring system for data transmission.

[0014] Preferably, a pressure sensor V is provided on the force transmission component of the intermediate connection component, and the pressure sensor V is connected to the monitoring system for data transmission.

[0015] Beneficial effects: The present invention provides a foundation pit steel support system based on an axial force loading device, which has the following advantages: (1) The present invention adopts an electromagnetic loading method, and realizes precise adjustment of the axial loading force of the steel pipe by adjusting the current of the electromagnetic block, thereby avoiding the uneven loading or error problems caused by device errors or improper operation in traditional mechanical loading devices, and ensuring the accuracy and stability of the loading of the foundation pit support system.

[0016] (2) The present invention achieves uniform force transmission by injecting liquid oil, magnetorheological colloid or other force transmission media between the steel pipe and the loading device, thereby ensuring uniform load transfer and avoiding stress concentration caused by uneven load in traditional steel support systems, thereby effectively reducing the risk of structural damage caused by excessive local stress and improving the safety and reliability of the entire support system.

[0017] (3) The present invention adopts a simpler modular structural design, which makes the installation, disassembly and maintenance of the steel support structure more convenient. By reducing manual operations and simplifying the connection method of the device, the construction period and labor costs are reduced, thereby improving the economy of the overall project. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic structural diagram of the intermediate connection assembly of the present invention (clamped state); Figure 3 is a schematic diagram of the structure of the intermediate connection assembly of the present invention (open state); Figure 4 is a right side view (opened state) of the intermediate connection assembly of the present invention; Figure 5 It is a structural schematic diagram of the end axial force loading device of the present invention; Figure 6 It is a structural schematic diagram of the intermediate shaft force loading device of the present invention; In the figure: underground continuous wall 1, end fixing device 2, injection hole 2-1, intermediate connecting component 3, upper slot part 3-1, lower slot part 3-2, slide rod 3-3, support column 4, intermediate axial force loading device 5, intermediate electromagnetic block I5-1, intermediate electromagnetic block II5-2, intermediate coil I5-3, intermediate coil II5-4, intermediate cushion block 5-5, circular sleeve 5-6, cavity III5-7, bracket 6, steel pipe 7, force transmission component 8, force transmission plate 8-1, cavity I8-2, cushion block 9, pressure sensor I10-1, pressure sensor II10-2, pressure sensor III10-3, pressure sensor IV10-4, pressure sensor V10-5 monitoring system 11, electromagnetic block I12-1, electromagnetic block II12-2, coil I13-1, coil II13-2, cavity II14. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0020] Example 1, applied to urban subway foundation pit support During the construction of urban subways, foundation pits are usually located in the central area of ​​the city, where the groundwater level is high and the surrounding buildings are dense, resulting in a complex construction environment. Due to the large depth of the subway foundation pit, the support structure must withstand a large external load, and at the same time, it is also necessary to prevent the settlement or collapse of the soil inside and outside the foundation pit. Therefore, the steel support structure in this embodiment 1 is installed between the underground continuous walls on both sides, and the end axial force loading device applies an axial load to the steel support structure.

[0021] In this embodiment 1, the steel support structure includes two groups of end fixing devices 2, a plurality of steel pipes 7 and an intermediate connecting assembly 3. The two groups of end fixing devices 2 are fixed on two underground continuous walls 1, and the central axes of the two groups of end fixing devices 2 overlap. The adjacent steel pipes 7 are connected by the intermediate connecting assembly 3, and the steel pipes 7 at both ends are connected to the end fixing devices 2.

[0022] In this embodiment 1, the end fixing device 2 is fixed to the two sides of the underground continuous wall 1 in the form of a hollow cylinder, and the interior of the hollow cylinder is used to install the end axial force loading device 2 and the connecting steel pipe 7. The adjacent steel pipes 7 are connected by an intermediate connecting component 3.

[0023] In this embodiment 1, Figure 2-4As shown, the intermediate connection component 3 is a slot structure, which is used to clamp and install the steel pipe 7 to ensure the stable connection of the steel pipe at both ends. Specifically, the intermediate connection component 3 includes an upper slot component 3-1 and a lower slot component 3-2, and the upper slot component 3-1 and the lower slot component 3-2 are connected by a slide bar 3-3, and the slots 3-4 of the upper slot component 3-1 and the lower slot component 3-2 cooperate to form a circular cavity for clamping the steel pipe 7, and a force transmission component 8 is arranged in the circular cavity for uniformly transmitting the pressure of the steel pipe 7. When installing the steel support structure, it is only necessary to place the steel pipe 7 in the slot of the lower slot component 3-2 in the open state, and then press the upper slot component 3-1 downward to clamp the steel pipe 7.

[0024] In this embodiment 1, the force transmission assembly 8 includes two force transmission plates 8-1, and the two force transmission plates 8-1 are connected by rubber sealing along the circumferential direction to form a cavity I8-2 for injecting a force transmission medium.

[0025] In this embodiment 1, Figure 5 As shown, the end axial force loading device includes an electromagnetic block I12-1, an electromagnetic block II12-2, a coil I13-1, a coil II13-2 and a cushion block 9, wherein the electromagnetic block I12-1 and the electromagnetic block II12-2 are both arranged in the end fixing device 2, and the electromagnetic block II12-1 is located on a side close to the underground continuous wall 1, and the coil I13-1 and the coil II13-2 are respectively arranged corresponding to the electromagnetic block I12-1 and the electromagnetic block II12-2, so that the electromagnetic block I12-1 12-1 and the electromagnetic block II 12-2 repel each other, the cushion block 9 is arranged on the outside of the electromagnetic block I 12-1 and is in contact with the end of the steel pipe 7, the cavity II 14 is arranged on the inside of the electromagnetic block II 12-2, and the end fixture 2 is provided with an injection hole 2-1, which is connected with the cavity II 14, and cushion blocks 9 are arranged between the cavity II 14 and the end fixture 2 (or the underground continuous wall) and between the electromagnetic block I 12-1 and the steel pipe 7.

[0026] After installation, the repulsive force between the electromagnetic block I12-1 and the electromagnetic block II12-2 is adjusted by adjusting the current in the coil I13-1 and the coil II13-2, thereby achieving precise control of the axial force loading on the steel support structure to meet the support requirements of the foundation pit. In this process, the end axial force loading device can achieve very precise loading control, avoiding support failure or foundation pit deformation caused by excessive or insufficient loading.

[0027] In this embodiment 1, in order to ensure the stability of the foundation pit steel support structure during the construction process, a monitoring system 11 is also installed. A pressure sensor I10-1 is arranged in the cavity II in the end axial force loading device for detecting the actual conducted load, and the coil I13-1 and the coil II13-2 are both provided with a pressure sensor II10-2 for detecting the applied load; a pressure sensor V10-5 is arranged on the force transmission component 8 of the intermediate connection component 3, and the pressure sensors I10-1, II10-2 and V10-5 are all connected to the monitoring system 11 for data transmission.

[0028] In the present invention, a pressure sensor is used to monitor the stress state of the steel support structure in real time, and the monitored stress information is fed back to the monitoring system in real time, and the monitoring system displays the data. A control threshold can be set in the monitoring system 11. When abnormal pressure or unloading occurs, the current in coil I 13-1 and coil II 13-2 can be adjusted in time, and real-time monitoring can be performed to ensure the stability of the loading of the steel support structure and that the entire support system is always within a safe range. After the construction is completed, the upper card slot 3-1 and the lower card slot 3-2 in the intermediate connection assembly only need to be opened along the slide rail 3-3 to quickly disassemble the steel support structure, reducing the complexity of the disassembly process in the traditional steel support system and reducing labor and equipment costs.

[0029] In this embodiment 1, if the distance between the two underground continuous walls is too large, the technical solution of embodiment 2 can be adopted to increase multi-level axial force loading between the steel pipes as needed.

[0030] Example 2, applied to mine foundation pit support In the process of large-scale mining, the foundation pit is usually deep, and the soil and rock structure are complex. The support system needs to cope with sudden geological changes, soil settlement, and changes in loads inside and outside the foundation pit. In addition, the environment where the mine foundation pit is located is humid and corrosive substances exist. The support structure must have strong corrosion resistance and long-term stability. In view of the complex geological conditions of the mine foundation pit, this embodiment 2 is based on the specific depth and size of the mine foundation pit, and on the basis of embodiment 1, as shown in FIG. Figure 1 As shown, a plurality of intermediate axial force loading devices 5 are added, and each intermediate axial force loading device 5 is correspondingly arranged on the corbel 6 of the supporting column 4, and is used to apply axial loads to the steel pipes 7 at multiple positions, thereby performing multi-level axial force loading on the steel support system.

[0031] In this embodiment 2, Figure 6As shown, the intermediate axial force loading device 5 includes an intermediate electromagnetic block I5-1, an intermediate electromagnetic block II5-2, an intermediate coil I5-3, an intermediate coil II5-4, two intermediate cushions 5-5 and a circular sleeve 5-6. The circular sleeves 5-6 respectively fix the steel pipes 7 on both sides, and the ends of the steel pipes 7 on both sides are respectively in contact and connected with one side of the intermediate cushion 5-5. The intermediate coil I5-3 and the intermediate coil II5-4 are respectively arranged corresponding to the intermediate electromagnetic block I5-1 and the intermediate electromagnetic block II5-2, so that the intermediate electromagnetic block I5-1 and the intermediate electromagnetic block II5-2 repel each other. The intermediate cushion 5-5 cooperates with the intermediate electromagnetic block I5-3 and the intermediate electromagnetic block II5-4 (and cooperates with the circular sleeve 5-6 at the same time) to form a cavity III5-7 for injecting force transmission medium.

[0032] In this embodiment 2, a pressure sensor III10-3 is arranged in the cavity III5-7 of the intermediate axial force loading device 5, and a pressure sensor IV10-4 is arranged on the intermediate coil I5-3 and the intermediate coil II5-4. The pressure sensor III10-3 and the pressure sensor IV10-4 are both connected to the monitoring system 11 for data transmission.

[0033] The present invention can accurately control the axial force of each loading point by adjusting the current of the electromagnetic block in the end axial force loading device and the intermediate axial force loading device 5 according to the actual stress conditions of the foundation pit, thereby ensuring uniform stress on the support system. During the loading process, cavity I8-2, cavity II14, and cavity III5-7 can ensure that the load is evenly transferred to the contact surfaces between steel pipes, between steel pipes and underground continuous walls, and between the intermediate pads and steel pipes, avoiding local stress concentration, thereby improving the durability and safety of the support structure. In addition, oiling in cavity I8-2, cavity II14, and cavity III5-7 also effectively reduces friction and wear, and extends the service life of the equipment.

[0034] In the present invention, liquid oil is generally used as the force transmission medium. If the axial force is too large during the design stage, the liquid oil can be replaced with magnetorheological colloid, which has better force transmission efficiency and can adjust the density of the magnetorheological colloid in real time according to the actual loading conditions on site.

[0035] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A foundation pit steel support system based on an axial force loading device, characterized in that: It includes a steel support structure and an end axial force loading device, wherein: The steel support structure includes two groups of end fixtures, a plurality of steel pipes and an intermediate connection assembly. The two groups of end fixtures are fixed on two underground continuous walls, and the central axes of the two groups of end fixtures overlap. The adjacent steel pipes are connected by an intermediate connection assembly, and the steel pipes at both ends are connected to the end fixtures. The end axial force loading device is installed in the end head fixing device to apply axial load to the steel pipe.

2. The foundation pit steel support system based on the axial force loading device according to claim 1 is characterized in that: The end fixing device is a hollow cylinder, and the interior of the hollow cylinder is used to install the end axial force loading device and connect the steel pipe.

3. The foundation pit steel support system based on the axial force loading device according to claim 1 is characterized in that: The intermediate connection assembly is a clamping groove structure, which is used for clamping and installing the steel pipe.

4. The foundation pit steel support system based on the axial force loading device according to claim 2 is characterized in that: The intermediate connection component includes an upper clamping groove part and a lower clamping groove part, and the upper clamping groove part and the lower clamping groove part are connected by a sliding rod. The clamping grooves of the upper clamping groove part and the lower clamping groove part cooperate to form a circular cavity for clamping the steel pipe. A force transmission component is arranged in the circular cavity for evenly transmitting the pressure of the steel pipe.

5. The foundation pit steel support system based on the axial force loading device according to claim 4 is characterized in that: The force transmission assembly includes two force transmission plates, and the two force transmission plates are connected in a circumferential sealing manner using rubber to form a cavity I for injecting a force transmission medium.

6. The foundation pit steel support system based on the axial force loading device according to claim 1 is characterized in that: The end axial force loading device includes an electromagnetic block I, an electromagnetic block II, a coil I, a coil II and two cushion blocks. The electromagnetic block I and the electromagnetic block II are both arranged in an end fixing device, and the electromagnetic block II is located on a side close to the underground continuous wall. The coil I and the coil II are respectively arranged corresponding to the electromagnetic block I and the electromagnetic block II, so that the electromagnetic block I and the electromagnetic block II repel each other. The electromagnetic block II cooperates with the end fixing device to form a cavity II for injecting a force transmission medium, and the end fixing device is provided with an injection hole, which is connected to the cavity II. Cushions are provided between the cavity II and the end fixing device and between the electromagnetic block I and the steel pipe.

7. The foundation pit steel support system based on the axial force loading device according to claim 6 is characterized in that: It also includes a plurality of intermediate axial force loading devices, each of which is correspondingly arranged on the corbel of the supporting column to perform multi-level axial force loading on the steel support system.

8. The foundation pit steel support system based on the axial force loading device according to claim 7 is characterized in that: The intermediate axial force loading device includes an intermediate electromagnetic block I, an intermediate electromagnetic block II, an intermediate coil I, an intermediate coil II, two intermediate pads and a circular sleeve. The circular sleeves respectively fix the steel pipes on both sides, and the ends of the steel pipes on both sides are respectively in contact and connected with one side of the intermediate pad. The intermediate coil I and the intermediate coil II are respectively arranged corresponding to the intermediate electromagnetic block I and the intermediate electromagnetic block II, so that the intermediate electromagnetic block I and the intermediate electromagnetic block II repel each other. The intermediate pads cooperate with the intermediate electromagnetic block I and the intermediate electromagnetic block II to form a cavity III for injecting a force transmission medium.

9. The foundation pit steel support system based on the axial force loading device according to claim 7 is characterized in that: A pressure sensor I is arranged in cavity II in the end axial force loading device, and pressure sensors II are arranged on coils I and II. A pressure sensor III is arranged in cavity III of the intermediate axial force loading device, and pressure sensors IV are arranged on intermediate coils I and II. Pressure sensors I, II, III and IV are all connected to the monitoring system for data transmission.

10. The foundation pit steel support system based on the axial force loading device according to claim 4 is characterized in that: A pressure sensor V is provided on the force transmission component of the intermediate connection component, and the pressure sensor V is connected to the monitoring system for data transmission.

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