A deep foundation pit support pile leveling system based on stress and displacement feedback

Abstract

The present application relates to the technical field of support pile leveling, and particularly relates to a deep foundation pit support pile leveling system based on stress and displacement feedback, which comprises a support pile, a plurality of prestressed tendons are arranged in a circumferential array with the central axis in the support pile as the center, and the prestressed tendons extend out of the top of the support pile to form a tension section; a strain sensor is arranged in the support pile and used for monitoring the strain of the support pile; an inclination sensor is arranged at the top center of the support pile and used for detecting the inclination angle of the support pile; a tensioning mechanism is arranged at the upper part of the support pile and movably sleeved on the tension section of the prestressed tendon; and a control system is used for receiving the monitoring data of the strain sensor and the inclination sensor, and exerting or releasing prestress on the prestressed tendon through the tensioning mechanism to adjust the posture of the support pile. The present application avoids the situation that the support pile loses the supporting effect on the foundation pit due to excessive inclination and / or deformation, thereby effectively improving the safety and reliability of the deep foundation pit support structure.

Description

Technical Field

[0001] This invention relates to the field of leveling technology for support piles, and in particular to a leveling system for deep foundation pit support piles based on stress and displacement feedback. Background Technology

[0002] As an important component of deep foundation pit support structures, retaining piles can effectively improve the bearing capacity of the soil, reduce the horizontal displacement and settlement of the soil around the foundation pit, and reduce the impact of groundwater on the foundation pit, thereby ensuring the safety and stability of the foundation pit.

[0003] Traditional deep foundation pit support piles are mostly passive support structures, relying primarily on their own stiffness and strength to resist lateral soil pressure. When soil pressure changes, the support piles can only passively bear the load and cannot actively adapt to deformation. In some complex geological conditions, such as soft soil strata and water-rich strata, the soil properties are unstable, easily leading to significant deformation and uneven settlement. Traditional support piles often cannot respond to these changes in a timely and effective manner, resulting in poor support performance. During construction, traditional support piles typically lack real-time monitoring methods for deformation and stress on the support structure. Construction personnel cannot promptly grasp the working status of the support piles and cannot adjust and optimize them according to actual conditions. Once abnormalities occur, measures are often not taken in time, increasing project risks. Summary of the Invention

[0004] To address at least one of the aforementioned technical problems, this invention proposes a deep foundation pit support pile leveling system based on stress and displacement feedback. This system aims to solve the problem that existing traditional support piles cannot monitor the tilt and / or deformation of the pile body in real time and dynamically adjust the pile body posture to a balanced state.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention proposes a leveling system for deep foundation pit support piles based on stress and displacement feedback, comprising:

[0007] The support pile has a plurality of prestressed tendons arranged in a circular array around the central axis of the support pile, and the prestressed tendons extend out of the top of the support pile to form a tensioning section.

[0008] A strain sensor is installed inside the support pile to monitor the strain of the support pile.

[0009] An inclination sensor is installed at the top center of the support pile to detect the inclination angle of the support pile.

[0010] The tensioning mechanism is installed on the upper part of the support pile and its movable limit sleeve is fitted on the tensioning section of the prestressed tendon;

[0011] The control system, in which the strain sensor, the tilt sensor, and the tensioning mechanism are connected, is used to receive monitoring data from the strain sensor and the tilt sensor, and to apply or release prestress to the prestressed tendons through the tensioning mechanism to adjust the posture of the support pile.

[0012] Preferably, the strain sensor is a resistance strain gauge type strain sensor.

[0013] Preferably, the number of the resistance strain gauge type strain sensors is 3, and the included angle between adjacent resistance strain gauge type strain sensors is 120°.

[0014] Preferably, the resistance strain gauge strain sensor is disposed on the outer side of the circumference formed by the prestressing tendons.

[0015] Preferably, the tilt sensor is a foot-operated tilt sensor.

[0016] Preferably, the tensioning mechanism includes an anchoring device sleeved on the tensioning section, and a jack is provided between the anchoring device and the top of the support pile. The jack is connected to an electric oil pump through a pipeline.

[0017] Preferably, the anchoring device includes an anchoring plate, the anchoring plate having anchor holes for easy movement of the tensioning section, and a fixed anchor at the end of the tensioning section away from the support pile.

[0018] Preferably, the fixed anchor is a mechanical anchor, which is either a wedge-type anchor or a nut-type anchor.

[0019] Preferably, the support pile leveling system further includes a control component, which includes a microcontroller connected to the control system for receiving control commands from the control system. The microcontroller is connected to the input terminal of the drive circuit, and the output terminal of the drive circuit is connected to the electric oil pump for controlling the motor power supply, speed, and direction of the electric oil pump.

[0020] Preferably, the prestressing tendon is a steel strand, and the outer layer of the steel strand is provided with an anti-rust coating.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention utilizes strain sensors and tilt sensors installed on the pile body to monitor the strain and tilt status of the pile in real time. Based on the data monitored by the strain and tilt sensors, the control system adjusts the prestress of the prestressing tendons by controlling the tensioning mechanism, restoring the pile body to a balanced state. This prevents the support pile from losing its supporting function for the foundation pit due to excessive tilting and / or deformation, thereby effectively improving the safety and reliability of deep foundation pit support structures. The leveling system in this embodiment can adapt to various working conditions in real time (such as groundwater fluctuations and sudden changes in soil properties), reducing work stoppages and rectifications caused by support problems during construction, improving overall project efficiency, and reducing time and economic costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a deep foundation pit support pile leveling system based on stress and displacement feedback;

[0024] Figure 2 This is a schematic diagram showing the installation position of the strain sensor in this utility model;

[0025] Figure 3 This is a schematic diagram of the anchoring device in this utility model;

[0026] Figure 4 This is a schematic diagram showing the configuration of the jack and electric oil pump in this utility model;

[0027] In the diagram: 10, support pile; 20, prestressed tendon; 201, tensioning section; 30, strain sensor; 40, tilt sensor; 50, tensioning mechanism; 501, anchoring device; 5011, anchoring plate; 50111, anchor hole; 502, jack; 503, electric oil pump; 60, control system. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments of the present invention.

[0029] Example 1

[0030] Please refer to Figure 1-4 As shown, a deep foundation pit support pile leveling system based on stress and displacement feedback includes:

[0031] The support pile 10 has a number of prestressed tendons 20 arranged in a circular array around the central axis of the support pile 10. The prestressed tendons 20 extend out of the top of the support pile 10 to form a tensioning section 201.

[0032] A strain sensor 30 is installed inside the support pile 10 to monitor the strain of the support pile 10.

[0033] Inclination sensor 40 is installed at the top center of the support pile 10 to detect the inclination angle of the support pile 10.

[0034] Tensioning mechanism 50 is installed on the upper part of support pile 10 and is movable and limited to tensioning section 201 of prestressed tendon 20;

[0035] The control system 60, strain sensor 30, tilt sensor 40 and tensioning mechanism 50 are connected to the control system 60 to receive the monitoring data of strain sensor 30 and tilt sensor 40, and to apply or release prestress to prestressed tendon 20 through tensioning mechanism 50 to adjust the posture of support pile 10.

[0036] This embodiment uses strain sensors 30 and tilt sensors 40 installed on the pile body of the support pile 10 to monitor the strain and tilt state of the pile body in real time. Based on the data monitored by the strain sensors 30 and tilt sensors 40, the control system 60 controls the tensioning mechanism 50 to adjust the prestress of the prestressed tendons 20, restoring the pile body to a balanced state. This prevents the support pile 10 from losing its support function for the foundation pit due to tilting and / or excessive deformation, thereby effectively improving the safety and reliability of the deep foundation pit support structure. The leveling system in this embodiment can adapt to various working conditions in real time (such as groundwater fluctuations and sudden changes in soil properties), reducing work stoppages and rectifications caused by support problems during construction, improving overall project efficiency, and reducing project time and economic costs.

[0037] It should be noted that, in this embodiment, the prestressing tendons 20 of the support pile 10 are high-strength, low-relaxation steel strands, which enable the steel strands to withstand greater tensile stress and provide sufficient prestress adjustment space for the support pile 10. When the control system 60 determines that the pile body needs to adjust its posture, the steel strands can apply or release sufficient tension through the tensioning device to effectively change the stress state of the pile body, achieve the functions of anti-tilting and deformation suppression, and meet the strength requirements under the complex stress environment of deep foundation pits.

[0038] Meanwhile, due to the low relaxation of the steel strands, the stress loss of the steel strands is small under long-term stress, and they can maintain a stable prestress value. This ensures that the equilibrium state of the support pile 10 can be maintained for a long time after dynamic adjustment, reducing the frequency of secondary adjustment caused by prestress relaxation and improving the stability and durability of the system.

[0039] In addition, in this embodiment, the outer layer of the steel strand has an anti-rust coating to improve the durability of the steel strand in humid environments and increase the service life of the steel strand.

[0040] Please refer to Figure 1 and Figure 2As shown, in this embodiment, the strain sensor 30 is a resistance strain gauge type strain sensor 30, which is disposed on the outer side of the circumference formed by several prestressing tendons 20. Furthermore, there are three resistance strain gauge type strain sensors 30, and the included angle between adjacent resistance strain gauge type strain sensors 30 is 120°.

[0041] It should be noted that the core of the resistance strain gauge strain sensor 30 is the strain gauge, and its basic principle is to utilize the characteristic that "the resistance of a metal conductor changes with its deformation (elongation or shortening)".

[0042] Specifically, strain gauges are attached to the concrete surface of the support pile 10 (or at a predetermined position inside the pile). When the pile experiences minor strain (tension or compression) due to stress, the strain gauges deform synchronously with the pile. The deformation of the metal grid of the strain gauge causes changes in its length and cross-sectional area, which in turn causes a change in its resistance value (resistance increases during tension and decreases during compression).

[0043] The strain sensor 30 converts the resistance change into a measurable electrical signal (voltage or current) through circuits such as a Wheatstone bridge. After amplification and processing, the signal is transmitted to the control system 60 to realize the quantitative monitoring of the pile strain.

[0044] Understandably, to accurately reflect the overall strain of the support pile 10, multiple sets of strain sensors 30 can be installed at different heights of the support pile 10. Specifically, because the soil pressure, bending moment, etc., experienced by the deep foundation pit support pile 10 at different depths (heights) during the stress process are significantly different (e.g., the stress state near the bottom of the pit may be drastically different from that near the top of the pit), multiple sets of strain sensors 30 distributed along the height can form a three-dimensional monitoring network to accurately locate the specific location of stress anomalies.

[0045] Meanwhile, when the tensioning mechanism 50 adjusts the prestressed tendons 20, the stress changes in the pile body will be transmitted along the height direction and exhibit a gradient distribution. Multiple strain sensors 30 can monitor the stress response at different heights in real time, determine whether the adjustment has achieved the expected effect (such as whether the stress is evenly distributed and whether abnormal strain has been eliminated), provide closed-loop feedback for the system, and avoid over-adjustment or under-adjustment.

[0046] Please refer to the figure. In this embodiment, the tilt sensor 40 is a foot-type tilt sensor 40.

[0047] It should be noted that the foot-type tilt sensor 40 typically incorporates a gravity sensing element (such as an accelerometer, gyroscope, or pendulum structure). It measures the tilt angle of an object by sensing the change in the angle between the direction of gravity and the sensor's own axis. The "foot-type" design refers to the sensor's bottom being tightly fitted to the surface of the support pile 10 via a stable contact end (similar to a "foot"), ensuring secure installation and a stable measurement reference, and reducing the impact of environmental interference such as vibration and impact on the data.

[0048] Unlike strain sensor 30, which focuses on "local stress and strain", foot-type tilt sensor 40 focuses on monitoring the macroscopic attitude of the pile. It can directly output the tilt angle of the pile in the horizontal direction (such as the X-axis and Y-axis) (usually with an accuracy of 0.1° or even higher), quickly determine whether the pile has tilted as a whole (such as tilting caused by the imbalance of soil pressure on both sides), and provide the system with intuitive data on "whether the attitude is unbalanced".

[0049] In this embodiment, the real-time angle data of the foot-type tilt sensor 40 is the direct basis for judging the adjustment effect. When the tensioning mechanism 50 adjusts the prestressed tendon 20, the control system 60 judges whether the pile body has returned to a vertical state through the angle change fed back by the tilt sensor 40, until the tilt angle drops to within the safe threshold, forming a closed-loop adjustment.

[0050] Understandably, in order to accurately reflect the degree of inclination of the pile, multiple tilt sensors 40 are installed at different heights at the center of the pile in this embodiment, so as to distinguish whether the pile is tilted as a whole or bent locally.

[0051] Please refer to Figure 1 , Figure 3 and Figure 4 As shown, in this embodiment, the tensioning mechanism 50 includes an anchoring device 501 sleeved on the tensioning section 201. A jack 502 is provided between the anchoring device 501 and the top of the support pile 10. The jack 502 is connected to an electric oil pump 503 through a pipeline. The anchoring device 501 includes an anchoring plate 5011. The anchoring plate 5011 has anchor holes 50111 to facilitate the movement of the tensioning section 201. A fixed anchor is provided at the end of the tensioning section 201 away from the support pile 10.

[0052] It should be noted that the above-mentioned fixed anchorage in this embodiment can be a mechanical anchorage such as a clamp-type anchorage or a nut-type anchorage.

[0053] Specifically, the wedge-type anchor mainly consists of an anchor ring and wedges, with the wedges clamping the prestressing tendon 20 using a wedge-shaped principle; the nut-type anchor mainly achieves fixation through the threaded engagement of the nut with the end of the prestressing tendon 20. Its characteristics include reliable anchoring, simple operation, and suitability for fixing high-strength prestressing tendons 20 such as steel strands. The specific structure of mechanical anchors is prior art, and this application will not provide a detailed description of its specific structure and working principle.

[0054] It is understood that, since the posture change of the support pile 10 in this embodiment may be uncertain at a certain height on a certain side, the jack 502 in this embodiment is movable and not fixed at a certain position of the support pile 10. At the same time, if necessary, multiple jacks 502 can be used simultaneously to adjust the tension of the prestressing tendons 20 synchronously.

[0055] In this embodiment, the leveling system for the support pile 10 also includes a control component. The control component includes a microcontroller connected to the control system 60 for receiving control commands from the control system 60. The microcontroller is connected to the input terminal of the drive circuit, and the output terminal of the drive circuit is connected to the electric oil pump 503 for controlling the power supply, speed, and direction of the electric oil pump 503.

[0056] It should be noted that the monitoring data from the strain sensor and tilt sensor can be transmitted to the data storage unit for the microcontroller to receive and read. The drive circuit is mainly responsible for converting the weak electrical control signals (such as digital signals) output by the microcontroller into strong electrical signals (such as voltage and current) that can drive the electric oil pump 503, controlling the start, stop, speed, and direction adjustment of the electric oil pump 503. The structure and working principle of the microcontroller and drive circuit are prior art and will not be described in detail here.

[0057] The installation method of the deep foundation pit support pile 10 leveling system provided by this utility model is as follows:

[0058] The strain sensor 30 and the tilt sensor 40 are pre-installed at the corresponding positions designed in the pile body of the support pile 10, and are installed together during the concrete pouring of the pile body to ensure that the strain sensor 30 and the tilt sensor 40 can collect data in real time when the pile body is in working condition.

[0059] The prestressing tendons 20 are evenly arranged around the pile body, and the tensioning section 201 of the prestressing tendons 20 is fixed by the anchoring device 501. Then, the electric oil pump 503 and the jack 502 are connected to the other end of the prestressing tendons 20.

[0060] All components of the control system 60 are integrated and installed in the equipment box on the side of the support pile 10. The electrical circuits of each sensor and tensioning device are connected and debugged to ensure that the system works normally.

[0061] The method of using the deep foundation pit support pile 10 leveling system provided by this utility model is as follows:

[0062] When the tilt sensor 40 indicates that the pile body has tilted by more than 5 degrees, the control system 60 quickly analyzes and processes the received data and records the data.

[0063] At the same time, the control system 60 calculates the amount of prestress that needs to be adjusted based on the situation exceeding the threshold, and sends a control command to the microcontroller in the control component. The microcontroller controls the drive circuit to drive the electric oil pump 503 to run, which in turn drives the jack 502 to tension the prestressed tendon 20 on the inclined side of the support pile 10, so as to adjust the amount of prestress of the prestressed tendon 20 and restore the pile body to a balanced state.

[0064] When the data monitored by the strain sensor 30 shows that the pile body has a strain greater than 20mm, it indicates that the local stress on the pile body is large. The control system 60 quickly analyzes and processes the received data and records the data.

[0065] At the same time, the control system 60 calculates the amount of prestress that needs to be adjusted based on the situation exceeding the threshold, and sends a control command to the microcontroller of the prestress adjustment system. The microcontroller controls the drive circuit to drive the electric oil pump 503, which in turn drives the jack 502 to relax the prestressing tendon 20, so as to adjust the amount of prestress in the prestressing tendon 20 and restore the pile body to a balanced state.

[0066] When the data monitored by the strain sensor 30 shows that the pile body has a horizontal displacement of more than 200mm, it indicates that the pile body has tilted or shifted as a whole. The control system 60 quickly analyzes and processes the received data and records the data.

[0067] The control system 60 calculates the required prestress level based on the threshold value and sends a control command to the microcontroller of the prestress adjustment system. The microcontroller controls the drive circuit to drive the electric oil pump 503, which in turn drives the jack 502 to stretch the prestressing tendon 20, thereby adjusting the prestress level of the prestressing tendon 20 and restoring the pile body to a balanced state.

[0068] The above description is a specific implementation of the embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A leveling system for deep foundation pit support piles based on stress and displacement feedback, characterized in that, include: The support pile (10) has a plurality of prestressed tendons (20) arranged in a circular array around the central axis of the support pile (10), and the prestressed tendons (20) extend out of the top of the support pile (10) to form a tensioning section (201). A strain sensor (30) is installed inside the support pile (10) to monitor the strain of the support pile (10); An inclination sensor (40) is disposed at the top center of the support pile (10) to detect the inclination angle of the support pile (10); The tensioning mechanism (50) is installed on the upper part of the support pile (10) and is movable and limited to the tensioning section (201) of the prestressed tendon (20); The control system (60) is connected to the strain sensor (30), the tilt sensor (40) and the tensioning mechanism (50) to receive the monitoring data of the strain sensor (30) and the tilt sensor (40) and to apply or release prestress to the prestressed tendon (20) through the tensioning mechanism (50) to adjust the posture of the support pile (10).

2. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 1, characterized in that, The strain sensor (30) is a resistance strain gauge type strain sensor (30).

3. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 2, characterized in that, The number of the resistance strain gauge strain sensors (30) is 3, and the included angle between adjacent resistance strain gauge strain sensors (30) is 120°.

4. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 2, characterized in that, The resistance strain gauge strain sensor (30) is disposed on the outside of the circumference formed by the prestressing tendons (20).

5. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 1, characterized in that, The tilt sensor (40) is a foot-operated tilt sensor (40).

6. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 1, characterized in that, The tensioning mechanism (50) includes an anchoring device (501) sleeved on the tensioning section (201), and a jack (502) is provided between the anchoring device (501) and the top of the support pile (10). The jack (502) is connected to an electric oil pump (503) through a pipeline.

7. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 6, characterized in that, The anchoring device (501) includes an anchoring plate (5011), which is provided with an anchor hole (50111) to facilitate the movement of the tensioning section (201) through which it passes. The end of the tensioning section (201) away from the support pile (10) is provided with a fixed anchor.

8. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 7, characterized in that, The fixed anchor is a mechanical anchor, which can be a wedge-type anchor or a nut-type anchor.

9. The deep foundation pit support pile leveling system based on stress and displacement feedback according to claim 7, characterized in that, The leveling system of the support pile (10) also includes a control component, which includes a microcontroller connected to the control system (60) for receiving control commands from the control system (60). The microcontroller is connected to the input terminal of the drive circuit, and the output terminal of the drive circuit is connected to the electric oil pump (503) for controlling the motor power supply, speed and direction of the electric oil pump (503).

10. The deep foundation pit support pile leveling system based on stress and displacement feedback according to any one of claims 1-9, characterized in that, The prestressing tendon (20) is a steel strand, and the outer layer of the steel strand is provided with an anti-rust coating.

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