Horizontal displacement and stress monitoring device and installation method for SMW method piles

Abstract

The present invention discloses a horizontal displacement and stress monitoring device for SMW method piles and an installation method, which relates to the field of foundation pit engineering construction. During on-site construction, the C-shaped bracket is installed and fixed on the web of the I-beam, and the inclinometer tube is fixed on the C-shaped bracket. In order to further protect the inclinometer tube, the present invention also uses cushioning materials and self-locking buckles to reduce the impact of vibration and shock on the inclinometer tube, thereby ensuring its safety and stability during the construction process. Secondly, the present invention realizes the comprehensive monitoring of the retaining structure by binding concrete strain gauges to the device, which can not only measure the deep horizontal displacement, but also monitor the stress change and distribution characteristics of the SMW method piles in real time. The present invention greatly improves the protection and fixing effect of the inclinometer tube during the construction of SMW method piles, and at the same time realizes the automatic monitoring of the stress state, providing important technical support for the safety management and construction quality of foundation pit excavation and support projects.

Description

Technical Field

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

[0002] For the horizontal displacement of the SMW method pile retaining structure, the installation of inclinometers is mostly used for monitoring. However, during the construction of the SMW method pile, the installation and fixation of the inclinometer have always been difficult points in the project. The embedding and fixation of the inclinometer not only require high precision but also must ensure that it is not damaged during the entire construction process to ensure the accuracy of the monitoring data. The traditional method of installing the inclinometer is usually to directly bury the inclinometer into the soil around the retaining structure or simply tie it to the structure. This method not only has a cumbersome installation process, is prone to problems such as inaccurate positioning and unstable fixation, but also the inclinometer is easily affected by vibration and impact during the installation process, resulting in deformation or damage of the pipe body, thereby affecting the monitoring effect and project quality.

[0003] The I-beam is the main component in the SMW method pile. How to firmly fix the inclinometer 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, some solutions have tried to protect the inclinometer through different fixing devices, but most of these solutions are complex in design, inconvenient in construction, and high in cost, making it difficult to be popularized and applied in actual projects.

[0004] In addition to the monitoring of (deep) horizontal displacement, the stress monitoring of the SMW method pile is also an important indicator for mastering the safety and stability of the retaining structure. However, the traditional stress monitoring means are complex and not easy to implement, making it difficult to meet the requirements of modern projects for accuracy and real-time performance. Accurately monitoring the stress state, distribution characteristics, and horizontal displacement of the SMW method pile helps to timely discover and prevent structural problems, and ensure the quality and safety of the foundation pit project. Summary of the Invention

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

[0006] The technical solution of the present invention is that the SMW method pile includes pre-embedded and installed I-beams;

[0007] The horizontal displacement and stress monitoring device includes a C-shaped bracket, an inclinometer tube, a sensor, a cushioning material, and an automatic acquisition unit. The cushioning material is fixedly installed 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 surface of the web are formed in the cushioning material. The C-shaped bracket is arranged in the bracket groove and fixedly connected to the web of the I-beam. The inclinometer tube is accommodated in the U-shaped groove and fixedly connected to the C-shaped bracket;

[0008] The sensor is fixedly installed on the front surface of the cushioning material and is connected to the automatic acquisition unit on the ground through a cable. The data of the sensor is collected and transmitted by the automatic acquisition unit.

[0009] Furthermore, the cushioning material is fixedly bonded to the web of the I-beam through an adhesive.

[0010] Furthermore, the C-shaped bracket includes a base plate and a support plate fixedly connected. Bolt holes are formed in the base plate, and the C-shaped bracket is fixed to the web of the I-beam through waterproof bolts penetrating the bolt holes. The support plate is arc-shaped and is used to fix and support the inclinometer tube;

[0011] A self-locking buckle is also installed at the arc-shaped opening of the support plate, and rubber gaskets are provided on the inner walls of the self-locking buckle and the C-shaped bracket.

[0012] Furthermore, the sensor includes a concrete strain gauge. One end of the cable is connected to the concrete strain gauge, penetrates into the cushioning material, and then leads out along the wire groove on the back surface of the cushioning material to be connected to the automatic acquisition unit on the ground.

[0013] Furthermore, the automatic acquisition unit includes a data acquisition unit, a data transmission unit, and an independent power supply device;

[0014] The data acquisition unit is connected to the sensor through a cable. The data transmission unit is connected to the data acquisition unit and transmits 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.

[0015] The construction is carried out according to the following steps:

[0016] Step 1: Measurement and marking;

[0017] According to the design drawings, determine the installation position of the C-shaped bracket on the web of the I-beam, measure the drilling positions on the web of the I-beam using a tape measure, and mark the drilling positions on the web of the I-beam using a marker pen;

[0018] Step 2: Preparation and installation of the bracket;

[0019] First, weld the self-locking buckle on the C-shaped bracket. Then, drill holes at the position where the web of the I-beam is located, and use waterproof bolts to pass through the bolt holes to fix the C-shaped bracket on the I-beam.

[0020] Step 3: Install the concrete strain gauge.

[0021] Install several concrete strain gauges on the front of the cushion material, and lead out the cables connecting the concrete strain gauges from the wire grooves of the cushion material.

[0022] Step 4: Cut and install the cushion material.

[0023] Cut the cushion material according to the dimensions of the I-beam and the inclinometer tube and the number of sensors. After embedding the cables into the reserved wire grooves on the back of the cushion material, use an adhesive to fix the cushion material in the middle area of the web of the I-beam.

[0024] Step 5: Fix the inclinometer tube.

[0025] Snap the inclinometer tube into the U-shaped grooves 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.

[0026] Step 6: Lower the I-beam and the inclinometer tube together.

[0027] Step 7: System debugging.

[0028] After the installation is completed, use an inclinometer and an automatic acquisition unit to debug the inclinometer tube and the sensors and collect the initial values. Subsequently, collect and analyze the data normally.

[0029] Furthermore, in Step 4, cut the cushion material according to the dimensions of the inclinometer tube and the number of sensors. After embedding the cables into the reserved wire grooves on the back of the cushion material, use an adhesive to fix the cushion material in the middle area of the web of the I-beam.

[0030] Furthermore, during Step 6, control the lowering speed and accuracy of the I-beam to ensure that the I-beam and the inclinometer tube are evenly stressed during the lowering process, and avoid tilting or swinging. During the lowering process, monitor the states of the I-beam and the inclinometer tube in real time to ensure that their positions are correct and there are no abnormalities. If any abnormal situation is found, immediately stop the lowering and conduct inspections and adjustments.

[0031] The protection and fixation device and installation method of the inclinometer tube for SMW method piles described in the present invention play an important role in the installation and protection of the inclinometer tube through the C-shaped bracket. Its advantages such as simple operation, stable reliability, flexibility, economy and high 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 measurement data, and ensure the smooth progress of the project. During the installation process, the use of cushioning materials and self-locking buckles reduces the impact of vibration on the inclinometer tube and ensures the accuracy of data. In addition, the bracket design is convenient for installation and disassembly, supports multiple uses, and significantly reduces construction costs and resource waste. The protection and fixation device of the present invention can also be installed with embedded sensors to monitor the stress changes of SMW method piles, providing comprehensive monitoring capabilities for the retaining structure.

[0032] Overall, the present invention provides an efficient, reliable and economical solution, greatly improving the protection and fixation effect of the inclinometer tube in the construction of SMW method piles, and at the same time realizing 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

[0033] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 is a schematic diagram of the structure of the C-shaped bracket of the present invention;

[0035] Figure 3 is a schematic diagram of the structure of the cushioning material of the present invention;

[0036] In the figure: 1 - I-beam; 12 - web; 2 - C-shaped bracket; 21 - base plate; 22 - support plate; 23 - bolt hole; 24 - waterproof bolt; 25 - self-locking buckle; 26 - rubber gasket; 3 - inclinometer tube; 4 - sensor; 41 - concrete strain gauge; 42 - cable;

[0037] 6 - cushioning material; 61 - U-shaped groove; 62 - wire groove; 63 - back of cushioning material; 64 - front of cushioning material; 65 - bracket groove; 8 - automatic acquisition unit; 81 - data acquisition unit; 82 - data transmission unit; 83 - independent power supply device. DETAILED DESCRIPTION OF THE INVENTION

[0038] In order to clearly illustrate the technical features of the present invention, the present invention will be described in detail below through specific embodiments and in conjunction with its drawings.

[0039] Since most current inclinometers are made of plastic, there will be resistance due to the presence of concrete when they are lowered along with H-beams in the SMW method piles. The existing fallback method is to drill holes separately in the soil around the retaining structure (SMW method piles) to lower the inclinometer. This not only has extremely high costs but also changes the measured target to the deep displacement of the soil rather than the displacement of the retaining structure (SMW method piles).

[0040] Therefore, considering the difficulties in pre-burying and fixing inclinometers in the current SMW method pile construction, low installation accuracy, and easy damage during the construction process, resulting in poor monitoring effects of the inclinometers and affecting the project quality. In the present invention, a special C-shaped bracket is installed on the web of the H-beam. The straight section part (base plate) of the bracket is fixed by waterproof bolts, and the arc section part (support plate) is used to fix and support the inclinometer. At the same time, combined with cushion protection and the assistance of the bracket, it is ensured that the inclinometer is not damaged during the construction process.

[0041] Specifically, it includes: H-beam 1, C-shaped bracket 2, inclinometer 3, sensor 4, automatic acquisition unit 8, cushion material 6, self-locking buckle 25 and related installation tools.

[0042] The H-beam is the main component in the SMW method, which plays the roles of supporting the structure, transferring loads, and stabilizing the construction.

[0043] The C-shaped bracket 2 is composed of two parts: a base plate 21 (straight section) and a support plate 22 (arc section); there are bolt holes 23 on the base plate 21, and the C-shaped bracket 2 can be fixed on the web 12 of the H-beam 1 through waterproof bolts 24; the support plate 22 is used to fix and support the inclinometer 3; the C-shaped bracket 2 is fixed at the middle position of the web 12 of the H-beam through waterproof bolts 24. While avoiding the direct action of external forces on the inclinometer 3 at the edge of the H-beam and ensuring the survival rate, it can better reflect the overall displacement change of the retaining structure.

[0044] The self-locking buckle 25 is integrated on the C-shaped bracket 2 and is used to fix the inclinometer 3; the self-locking buckle 25 and the rubber gasket 26 inside the C-shaped bracket provide additional friction and buffering effects.

[0045] The C-shaped bracket is integrally processed. The bracket material is made of high-strength steel, with relatively low costs, suitable for large-scale applications, and has high strength and durability. It can withstand large loads and stresses and can also be processed by common processing methods such as welding and drilling.

[0046] Inside the joint of each inclinometer tube, a C-shaped bracket is provided to provide sufficient support and protection. The inclinometer tube is commonly used to measure the deep horizontal displacement of the retaining structure (soil mass), generally a PVC tube with a diameter of 70mm to 90mm, and its integrity and functionality need to be maintained during the construction process.

[0047] The cushioning 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; several wire grooves 62 are preset on the back surface 63 of the cushioning material and fixed to the web 12 of the I-beam using an adhesive. A U-shaped groove 61 is opened on the front surface, and the size of the U-shaped groove 61 matches the size of the inclinometer tube 3 used in the project, allowing it to be firmly snapped into it; the part of the front surface 64 of the cushioning material except for the groove is used to install the concrete strain gauge 41; the cable 42 connecting the concrete strain gauge 41 passes through the cushioning material 6 and is led to the ground through the wire groove 62; the cushioning material 6 is dug with a bracket groove 65 at the position of the C-shaped bracket for installing the C-shaped bracket 2.

[0048] The material of the cushioning material 6 is selected as a suitable cushioning material, such as a rubber pad or a foam pad, according to the construction environment and the requirements of the inclinometer tube 3. The thickness of the cushioning material 6 needs to be slightly thicker than the thickness of the C-shaped bracket 2, but not too much thicker than the C-shaped bracket, to provide sufficient cushioning effect while maintaining the verticality of the inclinometer tube 3.

[0049] In other words, the cushioning material is laid on the suspended section of the inclinometer tube without bracket support, in contact with the web of the I-beam, to reduce vibration and impact and protect the inclinometer tube from damage; several wire grooves are preset on the back surface of the cushioning material and fixed to the web of the I-beam using an adhesive.

[0050] The adhesive uses high-strength epoxy resin or weather-resistant polyurethane to ensure stable bonding force under various environmental conditions.

[0051] In the present invention, the sensor 4 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 real-time monitor the stress and strain of the retaining structure (including I-beam or concrete) are within the protection scope of the present invention.

[0052] The automatic 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 automatic acquisition unit 8 through the cable 42, and then the data transmission unit 82 transmits the data wirelessly to the terminal for further processing; the independent power supply device 83 uses a photovoltaic panel to supply power to the automatic acquisition unit 8 and the sensor 4. The independent power supply device 83 enables the automatic acquisition unit not to rely on external power sources, which is especially suitable for construction sites far from the power grid or with unstable power supplies.

[0053] The construction of this case is carried out in the following steps:

[0054] Step 1: Measurement and marking;

[0055] According to the design drawing, 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 marker pen to mark the drilling positions on the web 12 of the I-beam to ensure that the marks are clear and accurate.

[0056] Step 2: Preparation and installation of the bracket;

[0057] First, weld the self-locking buckle 25 (other forms of integration can also be used) on the C-shaped bracket 2, then drill holes at specific positions on the web 12 of the I-beam, and use the waterproof bolt 24 to fix the C-shaped bracket 2 on the I-beam 1 through the bolt hole 23. Check the tightening condition of the waterproof bolt 24 before lowering to prevent loosening due to vibration.

[0058] Step 3: Install the concrete strain gauge;

[0059] Install a number of concrete strain gauges 41 on the front surface 64 of the cushion material to monitor the strain at different positions and orientations of the retaining structure in real time; lead out the cable 42 connecting the concrete strain gauge 41 from the cable groove 62 of the cushion material 6, avoid exposing the sensor cable 42 to the external environment, and add an additional protective sleeve at the cable inlet and outlet to prevent the cable from being damaged during long-term use.

[0060] Step 4: Cutting and installation of the cushion material;

[0061] Cut the cushion material 6 to an appropriate size according to the dimensions of the I-beam 1 and the inclinometer tube 3 and the number of sensors 4; after embedding the cable 42 into the reserved cable groove 62 on the back surface 63 of the cushion material, use an adhesive to fix the cushion material 6 in the middle area of the web 12 of the I-beam to prevent it from moving during the construction process.

[0062] Step 5: Fix the inclinometer tube;

[0063] Insert the inclinometer tube 3 into the U-shaped groove 61 of the C-shaped bracket 2 and the cushion material 6, and fasten the self-locking buckle 25 on the C-shaped bracket 2 until the inclinometer tube 3 is locked.

[0064] Step 6: Lower along with the I-beam;

[0065] Control the lowering speed and accuracy of the I-beam 1 to ensure uniform stress on the I-beam 1 and the inclinometer tube 3 during the lowering process, and avoid tilting or swinging. During the lowering process, monitor the states of the I-beam 1 and the inclinometer tube 3 in real time to ensure their correct positions and no abnormalities; if any abnormal situations are found (such as inclinometer tube offset, bracket loosening, etc.), immediately stop the lowering and conduct inspections and adjustments.

[0066] Step 7: System debugging;

[0067] After the installation is completed, use an inclinometer and an automated acquisition unit 8 to debug the inclinometer tube 3 and the sensor 4 and collect the initial values, and then normally conduct data collection and analysis.

[0068] After the inclinometer tube is buried, a measuring device needs to be lowered into the tube during measurement to obtain the displacement change of the inclinometer tube through the measuring device.

[0069] Through the above technical solutions, the present invention can effectively solve the problems of the installation and fixation of the inclinometer tube in the construction of the SMW method pile, ensure that the inclinometer tube is not damaged during the entire construction process, and thus guarantee the accuracy of the monitoring data and the project quality. The device and method of the present invention are applicable to the installation and fixation of other pipes or sensors that require precise positioning and protection, and have wide applicability.

[0070] It can solve the problems of inaccurate positioning and low installation efficiency during the fixation of the inclinometer tube, optimize the traditional fixation method, provide more reliable support and protection measures, ensure the safety and stability of the inclinometer tube during the construction process, and guarantee the accuracy and reliability of the monitoring data; moreover, the protection device of the present invention also integrates a concrete strain gauge to realize the monitoring of the stress change of the SMW method pile. Such a monitoring system has important guiding significance for the safety management and construction quality of the foundation pit excavation and support project. The C-shaped brackets and cushion materials in the present invention can also protect the embedded sensors and their cables.

[0071] The device and method of the present invention can also be applied to the installation and fixation of other pipes or sensors that require precise positioning and protection, and have wide applicability.

[0072] There are many specific implementation ways of the present invention. The above description is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements can still be made, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A method for installing 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 C-shaped bracket (2) comprises a base plate (21) and a support plate (22) which are fixedly connected to each other. The base plate (21) is provided with a bolt hole (23). 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). The sensor (4) is fixedly mounted on the front side of the cushion material (6) and 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); 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 side of the cushion material (6) and connected to the automatic collection unit (8) on the ground; 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.

2. The installation method of the horizontal displacement and stress monitoring device of the SMW construction method pile according to claim 1 is characterized in that: The self-locking buckle (25) and the inner wall of the C-shaped bracket (2) are provided with a rubber gasket (26).

3. The installation method of the horizontal displacement and stress monitoring device of the SMW construction method pile according to claim 1 is 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).

4. The installation method of the horizontal displacement and stress monitoring device of the SMW construction method pile according to claim 1 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.

5. The installation method of the horizontal displacement and stress monitoring device of the SMW construction method pile according to claim 1 is 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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