Steel support axial force automatic compensation and automatic alarm device and construction method thereof

Abstract

The application provides a steel support axial force automatic compensation and automatic alarm device and a construction method thereof, which comprises a steel support articulated joint, a steel support axial force compensation section located at one side of the steel support articulated joint, a steel support power supply and alarm section located at one side of the steel support axial force compensation section, and a general steel support section located at one side of the steel support power supply and alarm section. The application can ensure that the steel support can automatically compensate the axial force during the excavation of the foundation pit, and the overall construction operation process is factory-like, modular, very convenient and reliable, and can automatically monitor and alarm in three levels, thereby ensuring the safety of the foundation pit construction. In addition, the device has low cost and can be widely used.

Description

A device and construction method for automatic axial force compensation and alarm of steel support. Technical Field

[0001] This invention relates to the field of building engineering technology, and more specifically to a device and construction method for automatic compensation and alarm of axial force of steel support. Background Technology

[0002] With the rapid development of urbanization in China, underground projects such as urban rail transit, residential building basements, and municipal tunnels are becoming increasingly common. Deep foundation pit projects typically require a system of retaining structures and multiple internal supports to meet safety requirements. For ease of construction and to ensure the construction period, steel pipe supports are often used in deep foundation pit projects. During deep foundation pit construction, the principle of "support before excavation" must be followed. During excavation, internal supports must be erected layer by layer strictly according to the design drawings. After each layer of support is erected, as the excavation depth increases, the internal forces of the retaining structure and the axial forces of the erected internal supports continuously change. This may lead to complete loss of axial force in some supports or even tensile stress. For steel pipe supports, this can cause increased deformation of the retaining structure or even support instability and collapse. Therefore, the axial force of the steel pipe supports must be monitored in real time during deep foundation pit construction, and axial force must be added promptly to compensate.

[0003] The two most common methods for axial force compensation are: ① Manual compensation. Advantages: Low cost, only requiring consideration of daily labor costs. Disadvantages: Adding axial force to the upper steel support requires scaffolding for high-altitude work, posing safety hazards. ② Computer-controlled automatic servo compensation. Advantages: Automatically monitors the internal forces of multiple steel supports and automatically adds axial force. Disadvantages: Automatic servo compensation systems are expensive and difficult to use on a large scale in conventional foundation pits. Furthermore, the computer-controlled steel support axial force servo system consists of the fixed end of the steel support, the intermediate segment of the steel support, the movable head assembly with the compensation system, and a ground control center. The ground control center requires space on the construction site, which undoubtedly increases inconvenience for construction sites with limited space.

[0004] In summary, it is necessary to provide an automatic axial force compensation device that is convenient, practical, more operable, inexpensive, and equipped with automatic monitoring and alarm functions to solve the above-mentioned technical problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a device for automatic axial force compensation and automatic alarm of steel supports, which solves the technical problems in the above-mentioned patented solutions, such as the need to erect scaffolding for high-altitude operations to add axial force to the upper steel supports, which poses safety hazards, and the high cost of automatic servo compensation systems, which make them difficult to use on a large scale in conventional foundation pits.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions. A device for automatic compensation and automatic alarm of the axial force of a steel support includes a steel support flexible joint, a steel support axial force compensation section, and a steel support power supply and alarm device. The steel support flexible joint includes a matching wedge block and a hydraulic jack. The interior of the steel support axial force compensation section is provided with a high-strength spring, a spring cushion block, a movable limiting cylinder, a fixed limiting cylinder, a limiting screw and bolt, a displacement and axial force sensor, and a scale table module, etc. The exterior of the steel support power supply and alarm device is provided with a solar panel strip, a sensor data and power supply line, a three-stage alarm indicator light, etc. The steel support power supply and alarm device is connected to the displacement and axial force sensor module of the axial force compensation section through the sensor data line and the power supply line. When a large displacement occurs in the axial force compensation section, the sensor sends and receives signals, and the three-stage alarm indicator light can light three-color lights to visually feedback the alarm situation;

[0007] Furthermore, the high-strength spring supporting the axial force compensation section should have the characteristics of large stroke and low axial force change. For example, when the stroke increases by 10 mm, the maximum loss of axial force is 50 kN;

[0008] Furthermore, the solar panel strip is attached with a lithium battery with charge and discharge functions. The solar panel of the steel support power supply and alarm device has a power storage function and can supply power normally in rainy weather.

[0009] The beneficial effects of the present invention: The purpose of the present invention is to address the defects and deficiencies of the prior art. It can not only ensure that the steel support can automatically compensate the axial force during the foundation pit excavation, but the overall construction operation process is also simple, convenient, and reliable. Moreover, it can automatically monitor and alarm to ensure the safety of the foundation pit construction. In addition, the cost of this device is low and it can be widely promoted and used. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1: Schematic diagram of the split of the steel support flexible joint, the steel support axial force compensation section, and the steel support power supply and alarm section.

[0011] Figure 2: Schematic diagram of the steel support flexible joint.

[0012] Figure 3: Schematic diagram of the steel support axial force compensation section.

[0013] Figure 4: Schematic diagram of the steel support power supply and alarm section.

[0014] Figure 5: Internal tangential view after assembly.

[0015] Figure 6: Internal plan view after assembly.

[0016] Figure 7: External plan view after assembly.

[0017] As shown in the figure: 1. Hinged head; 2. Wedge block; 3. Movable limit cylinder; 4. Spring pad; 5. Matching high-strength spring; 6. Limit screw and bolt; 7. Displacement axial force sensor and scale module; 8. Fixed limit cylinder; 9. Fixing bolt; 10. Steel support intermediate section; 11. Solar panel strip; 12. Sensor data cable and power supply cable; 13. Three-level alarm indicator light; 14. Bolt hole. Detailed Implementation

[0018] The present invention is illustrated below with specific embodiments, which are not intended to limit the scope of the invention.

[0019] From a practical engineering perspective, and after thorough research into the actual site conditions, a technological process for solving the above problems has been disclosed.

[0020] To achieve the above objectives, the technical solution and detailed construction steps adopted by this invention are as follows:

[0021] As shown in Figures 1-7, a device for automatic compensation and alarm of axial force of steel support includes a steel support hinge head, a steel support axial force compensation section located on one side of the steel support hinge head, a steel support power supply and alarm section located on one side of the steel support axial force compensation section, and a general steel support section located on one side of the steel support power supply and alarm section.

[0022] The steel support hinge head includes a hinge head 1 and a wedge block 2 that matches the hinge head;

[0023] The steel support axial force compensation section includes a movable limiting cylinder 3 near the movable head of the steel support. A high-strength spring 5 is installed on one side of the movable limiting cylinder 3 and inside the steel support axial force compensation section. A spring pad 4 is installed between the movable limiting cylinder 3 and the high-strength spring 5. A fixed limiting cylinder 8 is installed on the side of the steel support axial force compensation section near the power supply and alarm section of the steel support. A limiting screw and bolt 6 are installed on the other side of the fixed limiting cylinder 8. Several bolt holes 14 are opened on the fixed limiting cylinder 8. Matching fixing bolts 9 are installed in the bolt holes 14. A displacement axial force sensor and scale module 7 are installed between the limiting screw and bolt 6 and the fixed limiting cylinder 8. The sensor is connected to the displacement axial force sensor module of the axial force compensation section through the sensor data line and power supply line. When the axial force compensation section generates a large displacement, the sensor transmits and receives signals and can intuitively feed the alarm by illuminating a three-color light through a three-level alarm indicator.

[0024] The steel support power supply and alarm section includes a steel support intermediate section 10. A solar panel strip 11 is installed on the outer wall of the steel support intermediate section 10. Several three-level alarm indicator lights 13 are connected to the outer side of the solar panel strip 11. The displacement axial force sensor and scale module 7 are connected to the solar panel strip 11 through sensor data line and power supply line 12.

[0025] The outer periphery of the swivel head 1 is provided with horizontal and vertical reinforcing ribs to improve the strength and service life of the swivel head.

[0026] The indicator lights of the level 3 alarm indicator 13 are yellow, orange, and red.

[0027] High-strength spring 5 is a spring with a large stroke and low axial force;

[0028] The solar panel 11 is equipped with a lithium battery with charging and discharging function. In order to prevent continuous rainy days or no sunlight at the steel support position, the solar panel of the steel support power supply and alarm device is equipped with a power storage function and can provide power normally in rainy weather.

[0029] Step 1: Based on the different design axial forces of each steel support in the design drawings, classify the steel supports of different segments and positions according to the magnitude of the single support axial force. They can be classified according to the standard of 500kN increments. For example: 0-500kN is grade A, 0-1000kN is grade B, 0-1500kN is grade C, 0-2000kN is grade D, and so on.

[0030] Step 2: Select a high-strength spring with matching stroke and performance based on the range corresponding to the axial force classification. For example, if the design axial force of the steel support is 600kN, a Class B spring can be selected, with the axial force varying within the range of 0-1000kN corresponding to the active stroke. High-strength springs should have the characteristics of large stroke and low axial force variation; for example, increasing the stroke by 10mm results in a maximum axial force loss of 50kN. During conventional foundation pit excavation, the horizontal displacement direction of the retaining structure generally points inward into the pit. However, during excavation or the erection of adjacent supports, the retaining structure may deform outwards. Under this condition, the axial force of the steel support may loosen or even detach. To avoid this adverse situation, a larger allowance for outward deformation is generally reserved for safety.

[0031] Step 3: After selecting a matching high-strength spring, prepare to assemble the steel support axial force compensation section: Apply high-performance lubricating oil to the high-strength spring, spring pad, the inside of the movable limit cylinder, the inside of the fixed limit cylinder, and the limit screw; put the high-strength spring and spring pad into the fixed limit cylinder one after another. The number of spring pads is calculated and determined according to parameters such as spring performance, compression stroke, and design axial force.

[0032] Step 4: Initial Compensation Axial Force and Initial Stroke Calibration. Adjust the initial compensation axial force by setting the thickness and number of spring washers, ensuring the movable and fixed limit cylinders are tightly pressed together. Make the initial axial force equal to the design axial force of the steel support. After adjustment, tighten the limit bolts to lock the initial compensation axial force and stroke. Simultaneously, adjust the displacement scale to near zero. To ensure accuracy and safety, this operation is recommended to be performed in the factory using standardized machinery. After assembly, transport the equipment to the site for final assembly.

[0033] Step 5: When erecting the steel support, place the axial force compensation section at the movable end and fix it to the adjacent standard section with bolts. After fixing, use a jack to tighten the steel support. Lock the jack when the axial force of the jack is equal to the design axial force of the steel support. Loosen the limit bolt by 3cm and insert a wedge to lock the initial stroke of the movable head compensation section. Adjust the displacement scale to zero to complete the erection of the steel support.

[0034] Step 6: Install the steel support displacement sensor and the three-level alarm device. When the axial force compensation section at the movable end of the steel support undergoes a large displacement, the three-level alarm indicator light will illuminate to indicate the alarm level.

[0035] Step 7: Install the remaining steel supports in sequence.

[0036] Since most of the steel supports for foundation pits are designed with large axial forces, in order to prevent the risk of air pressure in the compensation section, the stroke can be appropriately released after the stroke calibration of the compensation section is completed. When the steel support is erected, jacks are used on site to compress the compensation section to the design stroke and then lock it.

[0037] Although the invention has been shown and described primarily with reference to the defined embodiments, those skilled in the art will understand that numerous changes can be made to its construction and details without departing from the scope of protection defined by the claims. Therefore, the scope of protection of the invention is determined by the claims and includes all changes falling within the meaning or equivalent scope of the claims.

Claims

1. A device for automatic compensation and alarm of axial force of steel support, comprising a steel support hinge head, a steel support axial force compensation section located on one side of the steel support hinge head, a steel support power supply and alarm section located on one side of the steel support axial force compensation section, and a general steel support section located on one side of the steel support power supply and alarm section; characterized in that, The steel support hinge head includes a hinge head (1) and a wedge block (2) matching the hinge head; the steel support axial force compensation section includes a movable limiting cylinder (3) near one end of the steel support hinge head, a high-strength spring (5) is provided on one side of the movable limiting cylinder (3) and inside the steel support axial force compensation section, a spring pad (4) is provided between the movable limiting cylinder (3) and the high-strength spring (5), a fixed limiting cylinder (8) is provided on one side of the steel support axial force compensation section near the steel support power supply and alarm section, a limiting screw and bolt (6) are provided on the other side of the fixed limiting cylinder (8), and several screws are provided on the fixed limiting cylinder (8). Bolt hole (14), a matching fixing bolt (9) is provided in the bolt hole (14), a displacement axial force sensor and scale module (7) is provided between the limiting screw and bolt (6) and the fixed limiting cylinder (8); the steel support power supply and alarm section includes steel support intermediate section (10), the outer wall of the steel support intermediate section (10) is provided with solar panel strip (11), the outer side of the solar panel strip (11) is connected with several three-level alarm indicator lights (13), the displacement axial force sensor and scale module (7) is connected to the solar panel strip (11) through sensor data line and power supply line (12).

2. The device for automatic compensation and automatic alarm of axial force of steel support according to claim 1, characterized in that, The outer periphery of the movable head (1) is provided with horizontal reinforcing ribs and vertical reinforcing ribs.

3. The device for automatic compensation and automatic alarm of axial force of steel support according to claim 1, characterized in that, The indicator lights of the three-level alarm indicator (13) are yellow, orange and red.

4. The device for automatic compensation and automatic alarm of axial force of steel support according to claim 1, characterized in that, The high-strength spring (5) is a spring with a large stroke and low axial force.

5. The device for automatic compensation and automatic alarm of axial force of steel support according to claim 1, characterized in that, The solar panel (11) is equipped with a lithium battery that has charging and discharging capabilities.

6. A construction method for a device for automatic axial force compensation and automatic alarm of steel support as described in claim 1, characterized in that, The process includes the following steps: Step 1: Based on the different design axial forces of each steel support in the design drawings, classify the steel supports of different segments and positions according to the magnitude of the single support axial force, and classify them according to the standard of 500kN increments: 0-500kN is grade A, 0-1000kN is grade B, 0-1500kN is grade C, and 0-2000kN is grade D; Step 2: Select high-strength springs with corresponding matching stroke and performance according to the range corresponding to the axial force classification. The design axial force of the steel support is 600kN, so select grade B springs. The axial force corresponding to the active stroke varies within the range of 0-1000kN. The stroke increases by 10mm, and the maximum axial force loss is 50kN; Step 3: After selecting a matching high-strength spring (5), prepare to assemble the steel support axial force compensation section: apply lubricating oil to the high-strength spring (5), spring pad (4), the inside of the movable limit cylinder (3), the inside of the fixed limit cylinder (8), and the limit screw; put the high-strength spring (5) and spring pad (4) into the fixed limit cylinder (8) respectively; Step 4: Initial compensation axial force and initial stroke calibration; adjust the initial compensation axial force by setting the thickness and number of spring pads (4), so that the movable limit cylinder (3) and the fixed limit cylinder (8) are pressed together, so that the initial compensation axial force is equal to the steel support Step 5: When erecting the steel support, place the axial force compensation section of the steel support at the movable head end and fix it to the adjacent standard section with bolts. After fixing, use a jack to tighten the steel support. When the jack axial force is equal to the design axial force of the steel support, lock the jack, loosen the limit bolt by 3cm, insert a wedge to lock the initial stroke of the movable head compensation section, and adjust the displacement scale to zero. Step 6: Install the steel support displacement axial force sensor and three-level alarm indicator. Step 7: Install the remaining steel supports in sequence.

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