Distributed sensing and roadbed service state advanced forecasting system for rock-soil body pore pressure in seasonal freeze-thaw environment

Abstract

The invention discloses a seasonal freeze-thaw environment rock-soil body pore pressure distributed sensing and roadbed service state advanced forecasting system, which comprises a distributed pore pressure sensor network, a soil body pore pressure detection module, a data processing module and an early warning module, wherein the distributed pore pressure sensor network monitors pore pressure and temperature in a rock-soil body in real time; the soil body pore pressure detection module is used for detecting the change of the pore pressure of the soil body in the detection area and transmitting the detected soil body pore pressure data to the data processing module; the data processing module analyzes the received data to obtain abnormal information of the soil body pore pressure in the detection range, and transmits the abnormal information of the soil body pore pressure to the early warning module; and the early warning module sends out an early warning signal according to the received soil body pore pressure abnormal information. According to the invention, abnormal data can be analyzed and early warned, engineering management personnel can be helped to identify and deal with potential risks in time, and the safety of the engineering is improved.

Description

Technical Field

[0001] The present invention belongs to the field of pore pressure measurement and engineering service state warning in seasonal freeze-thaw environments, and relates to a geotechnical pore pressure sensing system in seasonal freeze-thaw environments, and more particularly to a distributed geotechnical pore pressure sensing and subgrade service state early warning system in seasonal freeze-thaw environments. Background Art

[0002] Geotechnical bodies play an important role in engineering construction, including infrastructure construction, underground engineering, tunnel engineering, etc. The physical and mechanical properties of geotechnical bodies, such as pore water pressure, aquifer distribution, soil strength, etc., directly affect the stability and safety of engineering. Under different environmental conditions, the behavior of geotechnical bodies may change significantly, especially in extreme environmental conditions such as cold regions or water-rich environments. In a low-temperature environment, the moisture in the geotechnical body may freeze, resulting in changes in the mechanical properties of the soil. The freezing and thawing processes will affect the strength, compressibility of the soil, and the change of pore water pressure. In a water-rich environment, the pore water pressure of the geotechnical body has a significant impact on the stability of the soil mass. Excessive moisture may cause liquefaction of the soil mass, reduction of strength, or rheological phenomena, affecting the stability of the project. During the construction and operation of highways, real-time monitoring of the pore water pressure (pore pressure) of geotechnical bodies is crucial for evaluating the stability of the soil mass. The change of pore pressure can reflect the internal stress distribution and hydrogeological conditions of the geotechnical body, thus predicting potential engineering risks. The current technical means mainly include: (1) Traditional sensors: Pore pressure sensors are installed on-site to measure the pore water pressure. However, these sensors usually can only provide local information and cannot effectively obtain the distributed data of geotechnical bodies. (2) Limited data acquisition: Existing monitoring systems often have difficulty covering the entire changing area of geotechnical bodies. Especially in complex cold and water-rich environments, traditional monitoring technologies may have problems such as incomplete data coverage or delayed feedback. (3) Limitations of the warning system: Existing engineering service state warning systems mostly rely on discrete measuring point data and it is difficult to achieve a comprehensive and timely early warning of the entire engineering state. In order to overcome the deficiencies of the existing technology, there is an urgent need for a geotechnical monitoring system that can achieve distributed sensing in seasonal freeze-thaw environments. Summary of the Invention

[0003] To improve the deficiencies of the existing technology, the present invention provides a system for distributed perception of pore pressure in geotechnical bodies in seasonal freeze-thaw environments and early prediction of the service state of roadbeds. Based on distributed fiber optic sensors using fiber Bragg gratings, this system can achieve distributed perception of pore pressure in geotechnical bodies in severe cold and water-rich environments. Combined with data transmission and processing modules, it can perform early prediction during the service state of roadbeds. The fiber optic sensors used in the present invention can be installed in harsh environments, and the system can easily perform data recording and transmission automatically. The present invention can measure pore pressure along various regions of the geotechnical body, achieving comprehensive data collection for the entire geotechnical body. Through this distributed measurement method, detailed pore pressure distribution data can be obtained to accurately evaluate the stability and safety of the geotechnical body. The present invention integrates an efficient soil pore pressure detection module, a data processing module, and an early warning module, supports real-time detection of soil pore pressure, can analyze abnormal data and give early warnings, helping engineering managers to identify and respond to potential risks in a timely manner and improving the safety of the project.

[0004] The object of the present invention is achieved through the following technical solutions:

[0005] A system for distributed perception of pore pressure in geotechnical bodies in seasonal freeze-thaw environments and early prediction of the service state of roadbeds, including a distributed pore pressure sensor network and an early prediction system, wherein:

[0006] The distributed pore pressure sensor network is composed of multiple soil pore pressure sensors based on fiber Bragg gratings. The soil pore pressure sensors based on fiber Bragg gratings are embedded at different depths and positions in the geotechnical body to monitor the pore pressure and temperature in the geotechnical body in real time, achieving all-round monitoring of the soil pore pressure within the required monitoring range;

[0007] The early prediction system is composed of a soil pore pressure detection module, a data processing module, and an early warning module;

[0008] The soil pore pressure detection module detects the change in the pore pressure of the soil in the detection area through the distributed pore pressure sensor network and transmits the detected soil pore pressure data to the data processing module;

[0009] The data processing module is used to receive the data transmitted by the soil pore pressure detection module and perform data analysis to obtain abnormal information about the soil pore pressure within the detection range, and transmit the abnormal information about the soil pore pressure to the early warning module;

[0010] The early warning module is used to issue an early warning signal according to the received abnormal information about the soil pore pressure.

[0011] A method for distributed perception of pore pressure in geotechnical bodies in seasonal freeze-thaw environments and early prediction of the service state of roadbeds using the above system, including the following steps:

[0012] Step 1: Distributed pore pressure sensor network layout

[0013] Step 1.1: A series of Fiber Bragg Grating based soil pore pressure sensors were installed in a PVC pipe with small drainage holes drilled in it and wrapped with non-woven geotextile around the sensors to allow the passage of water. The sensors were sealed with epoxy resin at both ends of the PVC pipe to prevent leakage between the sensors.

[0014] Step 1.2: Install the PVC pipes assembled in step 1.1 at different depths and locations in the soil of the desired monitoring area through drilling technology, and inject sand drainage material through the funnel and injection pipe to seal the sensor;

[0015] Step 2: Data Collection

[0016] The soil pore pressure detection module collects soil pore pressure data from the soil within the monitoring range through the distributed pore pressure sensor network formed by the soil pore pressure sensor based on the fiber Bragg grating installed in step 1, and transmits the data to the data processing module;

[0017] Step 3: Data Processing

[0018] The data processing module analyzes the received data, filters out abnormal data, and sends the abnormal information to the early warning module;

[0019] Step 4: The early warning module receives the abnormal information sent by the data processing module and issues an early warning.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. Improve monitoring accuracy and comprehensiveness: (1) Full coverage distributed sensing: By deploying a distributed fiber optic sensor network, the present invention can achieve all-round monitoring of pore pressure in rock and soil. This distributed measurement method overcomes the limitations of traditional point measurement technology and provides detailed information on the pore pressure distribution of rock and soil, thereby more comprehensively reflecting the actual state of the rock and soil. (2) High-resolution measurement: Fiber optic sensing technology provides high-resolution pore pressure measurement capabilities, which can accurately capture tiny pore pressure changes and improve the accuracy and reliability of monitoring data.

[0022] 2. Real-time data collection and analysis: (1) Strong real-time performance: The system can collect and process data in real time to ensure timely response to changes in pore pressure in the rock mass. This real-time monitoring capability enables the system to quickly identify potential problems and avoid safety hazards caused by data delays. (2) Efficient data processing: The data processing system automatically cleans, preprocesses and analyzes data, reducing the need for manual intervention and improving the efficiency and accuracy of data processing.

[0023] 3. Enhance environmental adaptability and system stability: (1) Adapt to extreme environments: The system design takes into account the special challenges in seasonal freeze-thaw environments and adopts anti-freezing, waterproof, and anti-corrosion materials and structures to ensure stability and long-term reliability under extreme environmental conditions. (2) Reduce maintenance costs: The highly durable design reduces the maintenance requirements of the system in harsh environments and lowers the long-term operation maintenance costs.

[0024] 4. Provide effective forecasts of the engineering service state: (1) Early warning ability: Based on real-time data and advanced prediction models, the present invention can make early forecasts and identify potential engineering risks in advance. This early warning ability provides sufficient time for engineering maintenance personnel to take preventive measures and reduces the risk of engineering accidents caused by changes in rock and soil masses. (2) Scientific decision-making support: By providing detailed forecast information and risk assessments, the system enables engineers and decision-makers to make more scientific decisions, improving the safety and reliability of the project.

[0025] 5. Improve engineering safety and construction efficiency: (1) Enhance safety: Through accurate monitoring and early warning, the system can effectively reduce accidents caused by changes in rock and soil masses and improve the overall safety of the project. (2) Optimize construction and maintenance: The functions of real-time monitoring and early forecasting make the engineering construction and maintenance processes more efficient, enabling timely adjustment of construction plans or maintenance measures and optimizing the project progress and resource utilization. Description of the Drawings

[0026] Figure 1 Schematic diagram of a pore pressure sensor based on fiber Bragg grating;

[0027] Figure 2 Schematic diagram of the installation of a pore pressure gauge array;

[0028] Figure 3 Schematic diagram of the structure of the early forecasting system;

[0029] Figure 4 Schematic diagram of the structure of the data processing module;

[0030] Figure 5 Flow chart of distributed sensing of pore pressure in rock and soil masses in seasonal freeze-thaw environments and early forecasting of subgrade service state. Detailed implementation manners

[0031] The technical solutions of the present invention will be further described below in conjunction with the drawings, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention.

[0032] The present invention provides a distributed perception system for pore pressure of geotechnical bodies in seasonal freeze-thaw environments and an advanced prediction system for the service state of subgrades. The system includes a distributed pore pressure sensor network and an advanced prediction system, wherein:

[0033] The distributed pore pressure sensor network is a distributed pore pressure sensor network based on fiber Bragg grating sensing technology and can operate stably in a severe cold and water-rich environment. The sensor network consists of multiple soil pore pressure sensors based on fiber Bragg grating. The soil pore pressure sensors based on fiber Bragg grating are embedded at different depths and positions in the geotechnical body to monitor the pore pressure and temperature in the geotechnical body in real time, so as to achieve an all-round monitoring of the soil pore pressure within the required monitoring range. Through the fiber Bragg grating sensing technology, the present invention can achieve high-resolution and long-term stable measurement of pore pressure. As Figure 1 shown, the soil pore pressure sensor based on fiber Bragg grating is installed in a PVC pipe as a piezometer. Small drainage holes are drilled in the PVC pipe, and the piezometer is wrapped with non-woven geotextile around it to allow water to pass through. The piezometer is glued and sealed at both ends of the PVC pipe with epoxy resin to prevent leakage between piezometers. The PVC pipe serves as a spacer and housing for the piezometer and the optical fiber. The final assembly is completed when the PVC pipe is placed into the borehole. As Figure 2 shown, multiple soil pore pressure sensors based on fiber Bragg grating are installed in a PVC pipe, and each soil pore pressure sensor based on fiber Bragg grating is surrounded by a sand cushion layer, and the sand cushion layers are sealed with bentonite. The assembled PVC pipe is completely grouted in the borehole according to the full grouting method.

[0034] As Figure 3 shown, the advanced prediction system consists of a soil pore pressure detection module, a data processing module, and an early warning module, wherein: the soil pore pressure detection module detects the change of the pore pressure of the soil in the detection area through the distributed pore pressure sensor network and transmits the detected soil pore pressure data to the data processing module; the data processing module is used to receive the data transmitted by the soil pore pressure detection module and perform data analysis to obtain the abnormal information of the pore pressure of the soil within the detection range, and transmit the abnormal information of the pore pressure of the soil to the early warning module; the early warning module is used to issue an early warning signal according to the received abnormal information of the soil pore pressure.

[0035] As Figure 4As shown in the figure, the data processing module consists of a soil pore pressure analysis unit and an abnormal pore pressure screening unit, where: the soil pore pressure analysis unit is used to receive the data transmitted by the soil pore pressure detection module, analyze the soil pore pressure data within the monitoring range, and compare the real-time data with the historically monitored data; the abnormal pore pressure screening unit is used to screen out the soil pore pressure data with large changes in real-time monitoring data compared with historical monitoring data, and transmit the abnormal information of the soil pore pressure to the early warning module.

[0036] In the present invention, the early warning module includes a display screen for generating early warning information and the location of the soil where abnormal information occurs.

[0037] In the present invention, the early warning module further includes an information sending device, which can timely send the early warning information to the hands of the staff, so that the staff can take timely measures to achieve the effect of early warning.

[0038] A method for distributed sensing of pore pressure in geotechnical bodies and early prediction of the service state of subgrades in seasonal freeze-thaw environments using the above system, as Figure 4 shown, the method includes the following steps:

[0039] Step 1: Layout of the distributed pore pressure sensor network

[0040] Step 1.1: Install a series of soil pore pressure sensors based on fiber Bragg gratings in a PVC pipe. Small drainage holes are drilled in the PVC pipe, and the sensors are wrapped with non-woven geotextiles around to allow water to pass through. The sensors are sealed with epoxy resin at both ends of the PVC pipe to prevent leakage between the sensors;

[0041] Step 1.2: Through drilling technology, install the assembled PVC pipe in step 1.1 at different depths and positions of the soil in the required monitoring area, and inject sand drainage materials through a funnel and a perfusion pipe to seal the sensors;

[0042] Step 2: Data acquisition

[0043] The soil pore pressure detection module collects the soil pore pressure data of the soil within the monitoring range through the distributed pore pressure sensor network formed by the soil pore pressure sensors based on fiber Bragg gratings installed in step 1, and transmits the data to the data processing module;

[0044] Step 3: Data processing

[0045] The data processing module analyzes the received data, screens out the abnormal data, and sends the abnormal information to the early warning module;

[0046] Step 4: The early warning module receives the abnormal information sent by the data processing module and issues an early warning.

[0047] Embodiment:

[0048] In this embodiment, the distributed perception of soil pore pressure and the advanced prediction system of subgrade service status in the seasonal freeze-thaw environment are installed at the subgrade slope position. The soil pore pressure detection module monitors the pore pressure of the soil within the range through a distributed pore pressure sensor network composed of fiber Bragg grating-based soil pore pressure sensors installed in an array. The soil pore pressure detection module transmits the soil pore pressure data collected by the distributed pore pressure sensor network to the data processing module. The data processing module receives the data from the soil pore pressure detection module, integrates and analyzes the data, screens out the abnormal soil pore pressure, and transmits the abnormal soil pore pressure information to the early warning module. The early warning module receives the abnormal information, issues an early warning message, and displays the location of the soil where the abnormal information is generated.

[0049] In this embodiment, the early warning module includes a display screen for generating early warning information and the location of the soil where the abnormal information is generated. The early warning module also includes an information sending device that can timely send the early warning information to the hands of the staff so that the staff can take timely measures to achieve the effect of early warning.

Claims

1. A distributed perception system for pore pressure of geotechnical bodies in seasonal freeze-thaw environments and an advanced prediction system for the service state of roadbeds, characterized in that The system includes a distributed pore pressure sensor network and an advanced prediction system, where: The distributed pore pressure sensor network is composed of multiple soil body pore pressure sensors based on fiber Bragg gratings. The soil body pore pressure sensors based on fiber Bragg gratings are embedded at different depths and positions in the geotechnical body to monitor the pore pressure and temperature in the geotechnical body in real time, so as to achieve an all-round monitoring of the soil body pore pressure within the required monitoring range; The advanced prediction system is composed of a soil body pore pressure detection module, a data processing module and an early warning module; The soil body pore pressure detection module detects the change of the pore pressure of the soil body in the detection area through the distributed pore pressure sensor network, and transmits the detected soil body pore pressure data to the data processing module; The data processing module is used to receive the data transmitted by the soil body pore pressure detection module and conduct data analysis to obtain the abnormal information of the soil body pore pressure within the detection range, and transmit the abnormal information of the soil body pore pressure to the early warning module; The early warning module is used to send out an early warning signal according to the received abnormal information of the soil body pore pressure.

2. The distributed perception system of pore pressure in geotechnical bodies under seasonal freeze-thaw environment and the early warning system for subgrade service status according to claim 1, characterized in that The soil body pore pressure sensor based on fiber Bragg gratings is installed in a PVC pipe as a piezometer. Small drainage holes are drilled in the PVC pipe, and the piezometer is wrapped around with non-woven geotextile to allow water to pass through. The piezometer is glued and sealed at both ends of the PVC pipe to prevent leakage between the piezometers.

3. The distributed perception system for pore pressure of rock and soil mass in seasonal freeze-thaw environment and the early prediction system for subgrade service state according to claim 1, characterized in that The data processing module is composed of a soil body pore pressure analysis unit and an abnormal pore pressure screening unit. Wherein: the soil body pore pressure analysis unit is used to receive the data transmitted by the soil body pore pressure detection module, analyze the soil body pore pressure data within the monitoring range, and compare the real-time data with the historically monitored data; the abnormal pore pressure screening unit is used to screen out the soil body pore pressure data with a large change compared with the historically monitored data in the real-time monitoring data, and transmit the abnormal information of the soil body pore pressure to the early warning module.

4. The distributed pore pressure sensing system for rock and soil masses in seasonal freeze-thaw environment and the advanced prediction system for subgrade service status according to claim 1, characterized in that The early warning module includes a display screen for generating early warning information and the location of the soil body where the abnormal information occurs.

5. The distributed pore pressure sensing system for rock and soil masses in seasonal freeze-thaw environment and the advanced prediction system for subgrade service status according to claim 1 or 4, characterized in that The early warning module also includes an information sending device for timely sending the early warning information to the hands of the staff, so that the staff can take measures in time to achieve the effect of early warning.

6. A method for distributed sensing of pore pressure in geotechnical bodies under seasonal freeze-thaw environment and early prediction of subgrade service status by using the system according to any one of claims 1-5, characterized in that The method includes the following steps: Step 1: Arrangement of the distributed pore pressure sensor network Step 1.1: Install a series of soil body pore pressure sensors based on fiber Bragg gratings in a PVC pipe. Small drainage holes are drilled in the PVC pipe, and the sensors are wrapped around with non-woven geotextile to allow water to pass through. The sensors are sealed with epoxy resin at both ends of the PVC pipe to prevent leakage between the sensors; Step 1.2: Through drilling technology, install the assembled PVC pipe in step 1.1 at different depths and positions of the soil body in the required monitoring area, and inject sand drainage materials through a funnel and a perfusion pipe to seal the sensors; Step 2: Data acquisition The soil pore pressure detection module collects data on the soil pore pressure of the soil within the monitored range through the distributed pore pressure sensor network formed by the fiber Bragg grating-based soil pore pressure sensors installed in Step 1, and transmits the data to the data processing module; Step 3: Data processing The data processing module analyzes the received data, screens out the abnormal data, and sends the abnormal information to the warning module; Step 4: The warning module receives the abnormal information sent by the data processing module and issues a warning.

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