阅读说明：本技术 一种基于分布式光纤动静应变测试的路基变形监测系统 (Roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain test ) 是由 何建平 李昌航 张世海 刘斌 于 2019-11-14 设计创作，主要内容包括：一种基于分布式光纤动静应变测试的路基变形监测系统,属于岩土结构安全监测领域。分布式的光纤应变传感器和温度传感器布设到路基结构中,与接入分布式光纤应变温度解调仪连接,分布式光纤温度传感器测试的温度信息对同位置的分布式光纤应变传感器进行温度补偿。分布式光纤动静应变测试控制模块向分布式光纤应变温度采集模块发出采集动、静应变的指令,路基变形监测预警及安全评估模块接收并分析处理动、静应变信号。本发明通过设置分布式光纤应变温度解调仪的数据采集条件分别实现分布式高精度静应变和分布式低精度动应变测试,并基于动静应变的信息分析对高速公路、高速铁路的路基岩溶突发塌陷和长期缓慢沉降变形进行同时监测,有效提高路基突发塌陷预警时间。(A roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain testing belongs to the field of safety monitoring of rock and soil structures. The distributed optical fiber strain sensors and the temperature sensors are arranged in the roadbed structure and connected with the access distributed optical fiber strain temperature demodulator, and temperature information tested by the distributed optical fiber temperature sensors is used for temperature compensation of the distributed optical fiber strain sensors at the same positions. The distributed optical fiber dynamic and static strain test control module sends a dynamic and static strain acquisition instruction to the distributed optical fiber strain temperature acquisition module, and the roadbed deformation monitoring early warning and safety evaluation module receives, analyzes and processes dynamic and static strain signals. According to the invention, distributed high-precision static strain and distributed low-precision dynamic strain tests are respectively realized by setting the data acquisition conditions of the distributed optical fiber strain temperature demodulator, and roadbed karst burst collapse and long-term slow settlement deformation of the expressway and the expressway are simultaneously monitored based on the information analysis of the dynamic and static strain, so that the early warning time of roadbed burst collapse is effectively prolonged.)

1. A roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain tests is characterized by comprising a distributed optical fiber strain sensor 1, a distributed optical fiber temperature sensor 2, a distributed optical fiber dynamic and static strain test conversion control module 3, a distributed optical fiber strain temperature demodulator 4 and a roadbed deformation monitoring, early warning and safety evaluation module 5,

the distributed optical fiber strain sensor 1 and the distributed optical fiber temperature sensor 2 are arranged in a roadbed structure, the distributed optical fiber strain sensor 1 is arranged in layers along the extending direction of a roadbed, the distributed optical fiber temperature sensor 2 and the distributed optical fiber strain sensor 1 are arranged in parallel in the same groove and are connected end to form a distributed signal transmission line and are connected into the distributed optical fiber strain temperature demodulator 4, the temperature information tested by the distributed optical fiber temperature sensor 2 is used for temperature compensation on the distributed optical fiber strain sensor 1 at the same position,

distributed optical fiber dynamic and static strain test control module 3 sends out the instruction of gathering dynamic and static strain to distributed optical fiber strain temperature acquisition module 4, the information transmission of gathering dynamic and static strain is to roadbed deformation monitoring early warning and safety evaluation module 5 in, when distributed optical fiber dynamic and static strain test conversion control module 3 sends out dynamic strain acquisition instruction, distributed optical fiber strain temperature demodulator 4's data acquisition parameter sets up to high-speed low accuracy collection condition: spatial resolution 2.0m, 2.0m apart from sampling resolution, brillouin frequency scanning step length 10MHz and the average number of times 2's of data acquisition 11 powers, data acquisition after setting up, when distributed optical fiber sound strain test conversion control module 3 sent static strain acquisition instruction, distributed optical fiber strain temperature demodulator 4's data acquisition parameter set up to the static collection condition of high accuracy: the spatial resolution is 0.5m, the distance sampling resolution is 0.1m, the Brillouin frequency scanning step length is 2MHz, and the average data acquisition frequency is 2 to the power of 14, the data acquisition is carried out after the setting,

the roadbed deformation monitoring early warning and safety evaluation module 5 receives, analyzes and processes the dynamic and static strain signals and carries out roadbed burst collapse early warning on the dynamic strain mutation signals; and carrying out roadbed deformation calculation on the static strain signal to evaluate the safety state of the roadbed.

2. The roadbed deformation monitoring system based on the distributed optical fiber dynamic and static strain test is characterized in that the distributed optical fiber dynamic and static strain test conversion control module 3 sends out a static strain acquisition control instruction under the following two conditions: firstly, send out static strain acquisition control instruction when subgrade deformation monitoring early warning and safety assessment module 5 sends out the early warning information that the subgrade is suddenly collapsed, sink the yardstick calculation analysis based on high accuracy static strain information, secondly "skylight time" that the high-speed railway stopped the operation, the highway sends out the static strain acquisition control instruction of subgrade in the operating period early in the morning.

Technical Field

The invention belongs to the field of safety monitoring of geotechnical structures, and particularly relates to a roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain tests.

Background

At present, the railway and highway construction industry in China is developed at a high speed which is not available before, and the business mileage and the operation speed are in the forefront of the world. The work of the construction of the Jing high-speed railway, the planning and adjustment of the railway layout in the New area of Xiongan, the planning of the railway hub in the core area of Jingjin Ji and the like is made an important progress, and a foundation is laid for the subsequent engineering construction. The roadbed is an important component of the line engineering, is a foundation for bearing the weight of a track and the load of a vehicle, and is the weakest and most unstable link in the line engineering, and high-speed railways and highways need to realize high-efficiency and high-speed safe operation of trains under the condition of high density, so that higher requirements are put forward on the safety of the roadbed. China belongs to one of the countries with frequent geological disasters, and particularly disasters such as karst collapse, uneven ground surface settlement and the like easily occur in southwest areas. With the improvement of the disaster prevention and reduction technology in China, measures such as reinforced geotextile, geogrid reinforcement, karst grouting and the like are adopted to reinforce the roadbed in areas where disasters are easy to occur. But under the effects of environment, external dynamic and static loads and the like and the influence of human engineering activities, the roadbed is difficult to be ensured not to be damaged any more. Therefore, in the vehicle operation process, if the road base deformation disaster can be monitored and early-warned, the vehicle operation accidents can be effectively reduced.

The high-speed railway and the highway belong to long-distance linear engineering, and the single-point sensing technology such as a fiber grating sensing technology, an electrical measurement sensing technology and the like is difficult to realize large-range continuous monitoring. The distributed optical fiber sensing technology can realize continuous strain test of dozens of kilometers or even hundreds of kilometers, and is a roadbed deformation monitoring technology which is relatively suitable for expressways and high-speed railways. At present, a method for monitoring sudden subgrade collapse by adopting a distributed optical fiber vibration sensing technology is reported, mainly by monitoring vibration information generated by the sudden subgrade collapse, belongs to a qualitative monitoring technology, and has the problems that the vibration monitoring information is easily interfered by environmental noise and the like. The reported roadbed deformation monitoring method developed by adopting the distributed optical fiber Brillouin strain sensing technology mainly monitors deformation caused by roadbed settlement, belongs to a quantitative monitoring technology, and has the problem that the single test time is longer in the order of minutes. At present, the running speed of high-speed railways and highways is higher and higher, the operation mileage is criss-cross, and meanwhile, the deformation and damage of the roadbed have the characteristics of karst burst collapse, long-term slow deformation and the like, so that the roadbed deformation monitoring technology has the characteristics of timeliness, wide range, accuracy and the like.

Disclosure of Invention

Aiming at the defects of the existing roadbed deformation monitoring technology, the invention aims to provide a roadbed deformation monitoring system based on a distributed optical fiber dynamic and static strain test, which can simultaneously realize roadbed sudden collapse monitoring and long-term high-precision deformation monitoring.

The technical scheme adopted by the invention is as follows:

a roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain testing comprises a distributed optical fiber strain sensor 1, a distributed optical fiber temperature sensor 2, a distributed optical fiber dynamic and static strain testing conversion control module 3, a distributed optical fiber strain temperature demodulator 4 and a roadbed deformation monitoring, early warning and safety evaluation module 5.

The distributed optical fiber strain sensor 1 and the distributed optical fiber temperature sensor 2 are distributed in a roadbed structure. The distributed optical fiber strain sensors 1 are arranged in layers along the extending direction of the roadbed, the distributed optical fiber temperature sensors 2 and the distributed optical fiber strain sensors 1 are arranged in parallel in the same groove and are connected end to form a distributed signal transmission line and are connected into the distributed optical fiber strain temperature demodulator 4. And temperature compensation is carried out on the distributed optical fiber strain sensor 1 at the same position through the temperature information tested by the distributed optical fiber temperature sensor 2.

The distributed optical fiber dynamic and static strain test control module 3 sends instructions for collecting dynamic and static strain to the distributed optical fiber strain temperature collecting module 4, and the collected dynamic and static strain information is transmitted to the roadbed deformation monitoring early warning and safety evaluation module 5. When the distributed optical fiber dynamic and static strain test conversion control module 3 sends out a dynamic strain acquisition instruction, the data acquisition parameters of the distributed optical fiber strain temperature demodulator 4 are set as high-speed low-precision acquisition conditions: the spatial resolution is 2.0m, the distance sampling resolution is 2.0m, the Brillouin frequency scanning step length is 10MHz, and the average data acquisition frequency is 11 times of 2, and data acquisition is carried out after setting. When the distributed optical fiber dynamic and static strain test conversion control module 3 sends out a static strain acquisition instruction, the data acquisition parameters of the distributed optical fiber strain temperature demodulator 4 are set as high-precision static acquisition conditions: the spatial resolution is 0.5m, the distance sampling resolution is 0.1m, the Brillouin frequency scanning step length is 2MHz, and the average data acquisition frequency is 2 to the power of 14, and data acquisition is carried out after setting.

The distributed optical fiber dynamic and static strain test conversion control module 3 sends out a static strain acquisition control instruction under the following two conditions, and sends out a dynamic strain acquisition control instruction under other conditions. Two cases are: firstly, a static strain acquisition control instruction is sent out when roadbed deformation monitoring early warning and safety evaluation module 5 sends roadbed burst collapse early warning information, and the roadbed collapse scale is calculated and analyzed based on high-precision static strain information. And secondly, sending a roadbed static strain acquisition control instruction during the skylight time of the high-speed railway parking and the early morning operation time period of the highway.

The roadbed deformation monitoring early warning and safety evaluation module 5 receives, analyzes and processes the dynamic and static strain signals and carries out roadbed burst collapse early warning on the dynamic strain mutation signals; and carrying out roadbed deformation calculation on the static strain signal to evaluate the safety state of the roadbed. The method specifically comprises the following steps: based on the dynamic strain information, once a dynamic strain signal is found to have a large mutation, roadbed collapse early warning information is sent out; and analyzing and calculating the deformation of the roadbed based on the static strain information, and sending roadbed settlement early warning information once the deformation exceeds a preset threshold value.

The invention has the advantages that: distributed high-precision static strain and distributed low-precision dynamic strain tests are respectively realized by setting data acquisition conditions of the distributed optical fiber strain temperature demodulator 4, and roadbed karst burst collapse and long-term slow settlement deformation of the expressway and the expressway are simultaneously monitored based on information analysis of the dynamic and static strain, so that the roadbed burst collapse early warning time is effectively prolonged, and the distributed optical fiber strain temperature demodulator has important application value for improving roadbed safe operation.

Drawings

Fig. 1 is a schematic structural diagram (roadbed longitudinal section) of a roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain testing.

Fig. 2 is a schematic structural diagram (roadbed cross section) of a roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain testing.

In the figure: 1, distributed optical fiber strain sensor; 2, distributed optical fiber temperature sensor; 3, a distributed optical fiber dynamic and static strain test conversion control module; 4, a distributed optical fiber strain temperature demodulator; and 5, a roadbed deformation monitoring, early warning and safety evaluation module.

Detailed Description

The following detailed description of the invention refers to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a roadbed deformation monitoring system based on distributed optical fiber dynamic and static strain testing. The specific implementation mode is that the distributed optical fiber strain sensors 1 are distributed in layers along the roadbed direction to sense the deformation information of each layer of the roadbed, and the distributed optical fiber temperature sensors 2 and the distributed optical fiber strain sensors 1 are distributed in parallel in the same groove to sense the temperature information of corresponding positions in the roadbed. The temperature information acquired by the distributed optical fiber temperature sensor 2 is used for carrying out temperature compensation on the static strain information acquired by the distributed optical fiber strain sensor 1. Distributed optical fiber strain sensors 1 and distributed optical fiber temperature sensors 2 of each layer in the roadbed are connected end to form an optical fiber sensing signal path and are connected into a distributed optical fiber strain temperature demodulator 4. In the roadbed deformation monitoring process, the distributed optical fiber dynamic and static strain test conversion control module 3 sends a dynamic strain acquisition instruction to the distributed optical fiber strain temperature demodulator 4, and the distributed optical fiber strain temperature demodulator 4 sets data acquisition parameters as high-speed low-precision acquisition conditions: the spatial resolution is 2.0m, the distance sampling resolution is 2.0m, the Brillouin frequency scanning step length is 10MHz, and the average data acquisition frequency is 11 times of 2, and then data acquisition is carried out. The collected dynamic strain information is transmitted to a roadbed deformation monitoring early warning and safety evaluation module 5, and once a sudden change dynamic strain signal is monitored, roadbed sudden collapse early warning information is sent. In the 'skylight time' of the stop of the high-speed railway or the time period of rare vehicles on the highway, the distributed optical fiber dynamic and static strain test conversion control module 3 sends out a static strain acquisition instruction, and the distributed optical fiber strain temperature demodulator 4 sets data acquisition parameters as high-precision static acquisition conditions: the spatial resolution is 0.5m, the distance sampling resolution is 0.1m, the Brillouin frequency scanning step length is 2MHz, and the average data acquisition frequency is 2 to the power of 14, and then data acquisition is carried out. The roadbed deformation monitoring early warning and safety evaluation module 5 analyzes the static strain signal in real time and calculates the corresponding roadbed deformation, and the roadbed settlement early warning information is sent out when the deformation exceeds a preset threshold value. In addition, after roadbed burst collapse early warning information based on dynamic strain information is sent out, the distributed optical fiber dynamic and static strain test conversion control module 3 sends out a static strain acquisition instruction, acquires strain information generated by collapse, and calculates and evaluates roadbed collapse scale.

According to the invention, distributed high-precision static strain and distributed low-precision dynamic strain tests are realized by setting data acquisition conditions of the distributed optical fiber strain temperature demodulator, and monitoring and early warning of roadbed burst collapse and long-term settlement deformation are carried out based on analysis of dynamic and static strain.

The above-mentioned embodiments only express the embodiments of the present invention, but not should be understood as the limitation of the scope of the invention patent, it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the concept of the present invention, and these all fall into the protection scope of the present invention.