Horizontal displacement and stress monitoring device of SMW construction method pile and installation method

Abstract

The invention discloses a horizontal displacement and stress monitoring device of an SMW construction method pile and an installation method, and relates to the field of foundation pit engineering construction. During on-site construction, the C-shaped support is fixedly installed on the web of the I-shaped steel, and the inclinometer pipe is fixed on the C-shaped support. In order to further protect the inclinometer pipe, the influence of vibration and impact on the inclinometer pipe is reduced by using a cushion material and a self-locking buckle, so that the safety and stability of the inclinometer pipe in the construction process are ensured. And secondly, the concrete strain gauge is bound on the device, so that comprehensive monitoring on the enclosure structure is realized, the deep horizontal displacement can be measured, and the stress change and distribution characteristics of the SMW construction method pile can be monitored in real time. According to the device, the inclinometer protecting and fixing effect in SMW pile construction is greatly improved, meanwhile, automatic monitoring of the stress state is achieved, and important technical support is provided for safety management and construction quality of foundation pit excavation and supporting engineering.

Description

Technical Field

[0001] The invention relates to the field of foundation pit engineering construction. Background Art

[0002] The horizontal displacement of the SMW pile retaining structure is mostly monitored by installing inclinometer tubes. However, in the construction of SMW piles, the installation and fixation of inclinometer tubes has always been a difficult point in the project. The pre-embedding and fixation of the inclinometer tubes not only require high precision, but also must ensure that they are not damaged during the entire construction process to ensure the accuracy of the monitoring data. The traditional method of installing inclinometer tubes is usually to bury the inclinometer tubes directly in the soil around the retaining structure or simply tie them to the structure. This method not only has a cumbersome installation process and is prone to problems such as inaccurate positioning and unstable fixation, but also the inclinometer tubes are susceptible to vibration and impact during the installation process, causing deformation or damage to the tube body, which in turn affects the monitoring effect and project quality.

[0003] I-beam is the main component of SMW pile construction. How to firmly fix the inclinometer tube on the I-beam to ensure that it is not damaged during the entire construction process has become an urgent problem to be solved. At present, there are some solutions that try to protect the inclinometer tube through different fixing devices, but most of these solutions are complex in design, inconvenient in construction, and high in cost, making them difficult to promote and apply in actual projects.

[0004] In addition to monitoring (deep) horizontal displacement, stress monitoring of SMW piles is also an important indicator for understanding the safety and stability of retaining structures. However, traditional stress monitoring methods are complex and difficult to implement, and it is difficult to meet the requirements of modern engineering for accuracy and real-time performance. Accurately monitoring the stress state, distribution characteristics and horizontal displacement of SMW piles can help to timely discover and prevent structural problems and ensure the quality and safety of foundation pit projects. Summary of the invention

[0005] In view of the above problems, the present invention proposes a horizontal displacement and stress monitoring device and installation method for SMW construction method piles. During on-site construction, the C-type bracket is installed and fixed on the web of the I-beam, and the inclinometer tube is fixed on the C-type bracket. In order to further protect the inclinometer tube, the present invention also uses cushion materials and self-locking buckles to reduce the impact of vibration and impact on the inclinometer tube, thereby ensuring its safety and stability during the construction process. Secondly, the present invention realizes comprehensive monitoring of the enclosure structure by binding concrete strain gauges on the device, which can not only measure deep horizontal displacement, but also monitor the stress changes and distribution characteristics of SMW construction method piles in real time.

[0006] The technical solution of the present invention is: the SMW construction method pile includes a pre-buried and installed I-beam; The horizontal displacement and stress monitoring device comprises a C-shaped bracket, an inclinometer tube, a sensor, a cushion material and an automatic acquisition unit. The cushion material is fixedly mounted on the web of the I-beam, and a U-shaped groove along the length direction of the I-beam and a bracket groove perpendicular to the web surface are opened on the cushion material. The C-shaped bracket is arranged in the bracket groove and is fixedly connected to the web of the I-beam. The inclinometer tube is accommodated in the U-shaped groove and is fixedly connected to the C-shaped bracket. The sensor is fixedly installed on the front side of the cushion material and is connected to an automatic collection unit on the ground via a cable, and the data of the sensor is collected and transmitted via the automatic collection unit.

[0007] Furthermore, the cushion material is fixedly bonded to the web of the I-beam by an adhesive.

[0008] Furthermore, the C-shaped bracket includes a base plate and a support plate which are fixedly connected to each other, the base plate is provided with a bolt hole, and the C-shaped bracket is fixed to the web of the I-beam by means of waterproof bolts inserted into the bolt holes; the support plate is arc-shaped and is used to fix and support the inclinometer tube; A self-locking buckle is also installed at the arc-shaped opening of the support plate, and a rubber pad is provided on the inner wall of the self-locking buckle and the C-shaped bracket.

[0009] Furthermore, the sensor includes a concrete strain gauge, one end of the cable is connected to the concrete strain gauge, and after penetrating into the cushion material, it is led out along the wire groove on the back of the cushion material and connected to the automatic collection unit on the ground.

[0010] Furthermore, the automated acquisition unit includes a data acquisition unit, a data transmission unit and an independent power supply device; The data acquisition unit is connected to the sensor via a cable, and the data transmission unit is connected to the data acquisition unit to transmit the collected data to the terminal; the independent power supply device includes a photovoltaic panel connected to the data acquisition unit and the data transmission unit.

[0011] Follow these steps to carry out the construction: Step 1: Measure and mark; According to the design drawings, determine the installation position of the C-shaped bracket on the web of the I-beam, use a tape measure to measure the drilling position on the web of the I-beam, and use a marking pen to mark the drilling position on the web of the I-beam; Step 2: Preparation and installation of the bracket; First, weld the self-locking clip onto the C-shaped bracket, then drill holes at the web of the I-beam, and use waterproof bolts to pass through the bolt holes to fix the C-shaped bracket onto the I-beam. Step 3: Install concrete strain gauge; Install several concrete strain gauges on the front of the cushion material, and lead the cables connected to the concrete strain gauges out from the cable duct of the cushion material; Step 4: Cutting and installing cushion materials; Cut the cushion material according to the size of the I-beam and inclinometer tube and the number of sensors; embed the cables into the reserved wire groove on the back of the cushion material, and use adhesive to fix the cushion material to the middle area of ​​the web of the I-beam; Step 5: Fix the inclinometer tube; Insert the inclinometer tube into the U-shaped groove of the C-shaped bracket and the cushion material, and fasten the self-locking buckle on the C-shaped bracket until the inclinometer tube is locked; Step 6: Lower the I-beam and inclinometer tube; Step 7: System debugging; After the installation is completed, the inclinometer and automated acquisition unit are used to debug the inclinometer tube and sensor and collect initial values, and data collection and analysis are carried out normally afterwards.

[0012] Furthermore, in step 4, the cushion material is cut according to the size of the inclinometer tube and the number of sensors; after the cable is embedded in the wire groove reserved on the back of the cushion material, the cushion material is fixed to the middle area of ​​the web of the I-beam using an adhesive.

[0013] Furthermore, in step six, the lowering speed and accuracy of the I-beam are controlled to ensure that the I-beam and the inclinometer tube are evenly stressed during the lowering process to avoid tilting or swinging. During the lowering process, the status of the I-beam and the inclinometer tube is monitored in real time to ensure that their positions are correct and there are no abnormalities. If any abnormality is found, the lowering is stopped immediately for inspection and adjustment.

[0014] The protection and fixing device and installation method of the SMW method pile inclinometer tube described in the present invention play an important role in the installation and protection of the inclinometer tube through the C-type bracket. Its advantages such as simplicity and ease of use, stability and reliability, flexibility and versatility, and economic efficiency make it an ideal choice in the construction of SMW method piles. After reasonable design and installation, it can effectively improve the construction quality and the accuracy of the measurement data, and ensure the smooth progress of the project. During the installation process, the use of cushion materials and self-locking buckles reduces the impact of vibration and impact on the inclinometer tube, ensuring the accuracy of the data. In addition, the bracket design is easy to install and disassemble, supports multiple uses, and significantly reduces construction costs and resource waste. The protection and fixing device of the present invention can also be installed with embedded sensors to realize the monitoring of stress changes in SMW method piles, providing a comprehensive monitoring capability for the surrounding structure.

[0015] In general, the present invention provides an efficient, reliable and economical solution, which greatly improves the protection and fixation effect of the inclinometer tube in SMW pile construction, and realizes the automatic monitoring of structural stress, providing important technical support for the safety management and construction quality of foundation pit excavation and support projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure of the C-type bracket of the present invention; Figure 3 It is a schematic diagram of the structure of the cushion material of the present invention; In the figure: 1-I-beam; 12-web; 2-C-type bracket; 21-base plate; 22-support plate; 23-bolt hole; 24-waterproof bolt; 25-self-locking buckle; 26-rubber liner; 3-inclinometer tube; 4-sensor; 41-concrete strain gauge; 42-cable; 6- cushion material; 61- U-shaped groove; 62- wire trough; 63- back of cushion material; 64- front of cushion material; 65- bracket slot; 8- automated acquisition unit; 81- data acquisition unit; 82- data transmission unit; 83- independent power supply device. DETAILED DESCRIPTION

[0017] In order to clearly illustrate the technical features of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0018] Since most of the current inclinometer tubes are made of plastic, there will be resistance due to the presence of concrete when the I-beams are lowered in the SMW piles. The second best solution is to drill a separate hole in the soil around the retaining structure (SMW piles) to lower the inclinometer tube. On the one hand, this is extremely costly, and on the other hand, the measured target will change to the deep displacement of the soil instead of the displacement of the retaining structure (SMW piles).

[0019] Based on this, considering that the pre-embedding and fixing of the inclinometer tube in the current SMW method pile construction is difficult, the installation accuracy is low, and it is easy to be damaged during the construction process, resulting in poor monitoring effect of the inclinometer tube, affecting the quality of the project. In the present invention, a special C-shaped bracket is installed on the web of the I-beam, the straight section of the bracket (base plate) is fixed by waterproof bolts, and the arc section (support plate) is used to fix and support the inclinometer tube. At the same time, the cushion layer protection and the assistance of the bracket are combined to ensure that the inclinometer tube is not damaged during the construction process.

[0020] Specifically, it includes: an I-beam 1, a C-shaped bracket 2, an inclinometer tube 3, a sensor 4, an automated acquisition unit 8, a cushion material 6, a self-locking buckle 25 and related installation tools.

[0021] The I-beam is the main component in the SMW construction method, which plays the role of supporting the structure, transferring loads and stabilizing construction.

[0022] The C-shaped bracket 2 is composed of a base plate 21 (straight section) and a support plate 22 (arc section). The base plate 21 is provided with bolt holes 23, and the C-shaped bracket 2 can be fixed to the web 12 of the I-beam 1 by waterproof bolts 24. The support plate 22 is used to fix and support the inclinometer tube 3. The C-shaped bracket 2 is fixed to the middle position of the web 12 of the I-beam by waterproof bolts 24, which can prevent the inclinometer tube 3 from being directly affected by external forces at the edge of the I-beam, ensure the survival rate, and better reflect the overall displacement change of the enclosure structure.

[0023] The self-locking buckle 25 is integrated on the C-shaped bracket 2 and is used to fix the inclinometer tube 3; the self-locking buckle 25 and the rubber pad 26 inside the C-shaped bracket provide additional friction and buffering effect.

[0024] The C-shaped bracket is integrally formed, and the bracket material is high-strength steel, which has relatively low cost and is suitable for large-scale applications. It has high strength and durability, can withstand large loads and stresses, and can also be processed by common processing methods such as welding and drilling.

[0025] A C-shaped bracket is provided inside the joint of each inclinometer tube to provide adequate support and protection. The inclinometer tube is commonly used to measure the deep horizontal displacement of the retaining structure (soil), and is generally a PVC tube with a diameter of 70mm~90mm, which needs to maintain its integrity and functionality during the construction process.

[0026] The cushion material 6 is laid on the web 12 of the I-beam to reduce vibration and impact and protect the inclinometer tube 3 from damage; a plurality of wire grooves 62 are preset on the back 63 of the cushion material and fixed to the web 12 of the I-beam with adhesive, and a U-shaped groove 61 is opened on the front. The size of the U-shaped groove 61 matches the size of the inclinometer tube 3 used in the project, so that it can be firmly inserted therein; the portion of the front 64 of the cushion material except the groove is used to install the concrete strain gauge 41; the cable 42 connected to the concrete strain gauge 41 passes through the cushion material 6 and is led to the ground through the wire groove 62; the cushion material 6 is dug with a bracket groove 65 at the position where the C-shaped bracket is provided for installing the C-shaped bracket 2.

[0027] The material of the cushion material 6 is selected according to the construction environment and the requirements of the inclinometer tube 3. Suitable cushion materials, such as rubber pads or foam pads, are selected. The thickness of the cushion material 6 needs to be slightly thicker than the thickness of the C-type bracket 2, but should not exceed the thickness of the C-type bracket by too much, so as to provide sufficient cushioning effect and maintain the verticality of the inclinometer tube 3.

[0028] In other words, the cushion material is laid on the suspended section of the inclinometer tube without support from a bracket, and is attached to the web of the I-beam to reduce vibration and impact and protect the inclinometer tube from damage; a wire groove is preset on the back of the cushion material and the cushion material is fixed to the web of the I-beam using an adhesive.

[0029] The adhesive uses high-strength epoxy resin or weather-resistant polyurethane to ensure stable bonding under various environmental conditions.

[0030] The sensor 4 described in the present invention takes the embedded concrete strain gauge 41 as an example. In addition to the strain gauge described in the present invention, other types of sensors that can monitor the stress and strain of the enclosure structure (including I-beams or concrete) in real time are within the protection scope of the present invention.

[0031] The automated acquisition unit 8 includes a data acquisition unit 81, a data transmission unit 82 and an independent power supply device 83; the data acquisition unit 81 stores the data collected by the sensor 4 in the automated acquisition unit 8 through a cable 42, and then the data transmission unit 82 transmits the data to the terminal wirelessly for further processing; the independent power supply device 83 uses photovoltaic panels to power the automated acquisition unit 8 and the sensor 4. The independent power supply device 83 enables the automated acquisition unit to be independent of an external power supply, and is particularly suitable for construction sites that are far away from the power grid or have unstable power supplies.

[0032] The construction of this case is carried out according to the following steps: Step 1: Measure and mark; According to the design drawings, determine the installation position of the C-shaped bracket 2 on the web 12 of the I-beam. The position should ensure that the inclinometer tube 3 can be stably fixed on the I-beam 1 and avoid affecting other construction operations; use a tape measure to measure the drilling positions on the web 12 of the I-beam to ensure that the spacing and positions of each hole are accurate; use a marking pen to mark the drilling positions on the web 12 of the I-beam to ensure that the markings are clear and accurate.

[0033] Step 2: Preparation and installation of the bracket; First, weld the self-locking buckle 25 (or integrate it in other forms) on the C-shaped bracket 2, then drill holes at specific positions of the web 12 of the I-beam, and use waterproof bolts 24 to fix the C-shaped bracket 2 on the I-beam 1 through the bolt holes 23. Check the tightness of the waterproof bolts 24 before lowering to prevent loosening due to vibration.

[0034] Step 3: Install concrete strain gauge; Several concrete strain gauges 41 are installed on the front side 64 of the cushion material to monitor the strain at different positions and directions of the enclosure structure in real time; the cable 42 connected to the concrete strain gauge 41 is led out from the wire groove 62 of the cushion material 6 to avoid the sensor cable 42 being exposed to the external environment, and additional protective covers are added at the cable inlet and outlet to prevent the cable from being damaged during long-term use.

[0035] Step 4: Cutting and installing cushion materials; According to the size of the I-beam 1 and the inclinometer tube 3 and the number of sensors 4, cut the cushion material 6 of appropriate size; after embedding the cable 42 into the wire groove 62 reserved on the back side 63 of the cushion material, use adhesive to fix the cushion material 6 to the middle area of ​​the web 12 of the I-beam to prevent it from moving during construction.

[0036] Step 5: Fix the inclinometer tube; The inclinometer tube 3 is inserted into the U-shaped groove 61 of the C-shaped bracket 2 and the cushion material 6 , and the self-locking buckle 25 on the C-shaped bracket 2 is buckled until the inclinometer tube 3 is locked.

[0037] Step 6: Lower the I-beam; Control the lowering speed and accuracy of the I-beam 1 to ensure that the I-beam 1 and the inclinometer tube 3 are evenly stressed during the lowering process to avoid tilting or swinging. During the lowering process, monitor the status of the I-beam 1 and the inclinometer tube 3 in real time to ensure that their positions are correct and there are no abnormalities; if any abnormality is found (such as inclinometer tube deviation, loose bracket, etc.), the lowering should be stopped immediately for inspection and adjustment.

[0038] Step 7: System debugging; After the installation is completed, the inclinometer and the automated acquisition unit 8 are used to debug the inclinometer tube 3 and the sensor 4 and collect initial values, and then the data collection and analysis are carried out normally.

[0039] After the inclinometer tube is buried, a measuring device needs to be placed in the tube for measurement, and the displacement change of the inclinometer tube is obtained through the measuring device.

[0040] Through the above technical solutions, the present invention can effectively solve the problem of installation and fixation of the inclinometer tube in SMW pile construction, ensuring that the inclinometer tube is not damaged during the entire construction process, thereby ensuring the accuracy of the monitoring data and the quality of the project. The device and method of the present invention are suitable for the installation and fixation of other pipelines or sensors that require precise positioning and protection, and have wide applicability.

[0041] It can solve the problems of inaccurate positioning and low installation efficiency when fixing the inclinometer tube, optimize the traditional fixing method, provide more reliable support and protection measures, ensure the safety and stability of the inclinometer tube during the construction process, and ensure the accuracy and reliability of the monitoring data; and the protection device of the present invention also integrates a concrete strain gauge to realize the stress change monitoring of the SMW method pile. This monitoring system has important guiding significance for the safety management and construction quality of foundation pit excavation and support engineering. The C-type bracket and cushion material in the present invention can also protect the embedded sensor and its cables.

[0042] The device and method of the present invention can also be applied to the installation and fixation of other pipelines or sensors that require precise positioning and protection, and has wide applicability.

[0043] There are many specific implementation ways of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A horizontal displacement and stress monitoring device for SMW piles, characterized in that: The SMW pile comprises a pre-buried I-beam (1); The horizontal displacement and stress monitoring device comprises a C-shaped bracket (2), an inclinometer tube (3), a sensor (4), a cushion material (6), and an automated acquisition unit (8); the cushion material (6) is fixedly mounted on the web (12) of an I-beam, and a U-shaped groove (61) along the length direction of the I-beam and a bracket groove (65) perpendicular to the web surface are provided on the cushion material (6); the C-shaped bracket (2) is arranged in the bracket groove (65) and is fixedly connected to the web (12) of the I-beam; the inclinometer tube (3) is accommodated in the U-shaped groove (61) and is fixedly connected to the C-shaped bracket (2); The sensor (4) is fixedly mounted on the front side of the cushion material (6) and is connected to an automatic collection unit (8) on the ground via a cable (42), and data of the sensor (4) is collected and transmitted via the automatic collection unit (8).

2. A horizontal displacement and stress monitoring device for SMW piles according to claim 1, characterized in that: The cushion material (6) is fixedly bonded to the web (12) of the I-beam by means of an adhesive.

3. The horizontal displacement and stress monitoring device for SMW piles according to claim 1, characterized in that: The C-shaped bracket (2) comprises a base plate (21) and a support plate (22) which are fixedly connected to each other; a bolt hole (23) is opened on the base plate (21); and the C-shaped bracket (2) is fixed to the web (12) of the I-beam (1) by means of a waterproof bolt (24) inserted into the bolt hole (23); the support plate (22) is arc-shaped and is used to fix and support the inclinometer tube (3); A self-locking buckle (25) is also installed at the arc-shaped opening of the support plate (22), and a rubber gasket (26) is provided on the inner wall of the self-locking buckle (25) and the C-shaped bracket (2).

4. The horizontal displacement and stress monitoring device for SMW piles according to claim 1, characterized in that: The sensor (4) comprises a concrete strain gauge (41); one end of the cable (42) is connected to the concrete strain gauge (41), and after penetrating the cushion material (6), is led outward along a wire groove (62) on the back of the cushion material (6) to be connected to an automatic data collection unit (8) on the ground.

5. The horizontal displacement and stress monitoring device for SMW piles according to claim 1, characterized in that: The automated acquisition unit (8) comprises a data acquisition unit (81), a data transmission unit (82) and an independent power supply device (83); The data acquisition unit (81) is connected to the sensor (4) via a cable (42); the data transmission unit (82) is connected to the data acquisition unit (81) to transmit the collected data to the terminal; and the independent power supply device (83) comprises a photovoltaic panel connected to the data acquisition unit (81) and the data transmission unit (82).

6. A method for installing the horizontal displacement and stress monitoring device for SMW piles according to claim 1, characterized in that: Follow these steps to carry out the construction: Step 1: Determine the installation position of the C-shaped bracket (2) on the web (12) of the I-beam, and mark the drilling position on the web (12) of the I-beam; Step 2: Weld the self-locking buckle (25) onto the C-shaped bracket (2), then drill a hole at the position where the web (12) of the I-shaped steel is located, and use a waterproof bolt (24) to pass through the bolt hole (23) to fix the C-shaped bracket (2) onto the I-shaped steel (1); Step 3: Install a concrete strain gauge (41) on the front side (64) of the cushion material, and lead the cable (42) connected to the concrete strain gauge (41) out from the cable groove (62) of the cushion material (6); Step 4: Cut the cushion material (6) and fix it to the web (12) of the I-beam Step 5: Insert the inclinometer tube (3) into the U-shaped groove (61), and snap the self-locking buckle (25) until the inclinometer tube (3) is locked. Step 6: Lower the I-beam and inclinometer tube; Step 7: After the installation is completed, the inclinometer and the automated acquisition unit (8) are used to debug the inclinometer tube (3) and the sensor (4) and collect initial values, and then the data collection and analysis are carried out normally.

7. The installation method of the horizontal displacement and stress monitoring device of the SMW construction method pile according to claim 6 is characterized in that: In step 4, the cushion material (6) is cut according to the size of the inclinometer tube (3) and the number of sensors (4); after the cable (42) is embedded in the wire groove (62) reserved on the back side (63) of the cushion material, the cushion material (6) is fixed to the middle area of ​​the web (12) of the I-beam using an adhesive.

8. The method for installing a horizontal displacement and stress monitoring device for SMW piles according to claim 6, characterized in that: During step six, the lowering speed and accuracy of the I-beam (1) are controlled to ensure that the I-beam (1) and the inclinometer tube (3) are evenly stressed during the lowering process to avoid tilting or swinging. During the lowering process, the status of the I-beam (1) and the inclinometer tube (3) is monitored in real time to ensure that their positions are correct and there are no abnormalities. If any abnormality is found, the lowering is stopped immediately for inspection and adjustment.

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