Subgrade Frost Heave Remote Monitoring System For High-speed Railway Based On Position Sensitive Detector

With the rapid development of railway construction, high-speed railway will cover a wide range of seasonal frozen soil areas in China. Subgrade frost heaving is the main problem to build high-speed railway in the seasonally frozen soil region and is a serious threat to railway operation safety. Therefore, real-time remote monitoring of subgrade frost heaving and timely guidance on maintenance are important for the protection of high-speed railway traffic security.In view of the subgrade frost heaving inspection methods commonly used at domestic and foreign, like observation posts and ground temperature measurements all have shortcomings. Thesis proposes a subgrade frost heave remote monitoring system for high-speed railway based on Position position sensitive detector (PSD). The system takes the hardware platform based on ARM and the illumination compensation algorithm, implementing the remote and high precision monitoring of subgrade frost heaving.Thesis firstly represents the working principle of PSD and the factors that influence PSD positioning accuracy, designs the micro displacement optical detection system based on laser, prism and PSD, and also proposes the overall scheme of subgrade frost heaving monitoring. Then, the PSD signal processing system based on ARM is designed, the processing, analogue-to-digital conversion., the storage and transmission of PSD output signal is implemented. The upper-computer software is designed, and the functions like data acquirement, data storage, real-time display of subgrade frost heaving is implemented. The impact of background light on PSD monitoring signal is described in detail. And the illumination compensation algorithm is proposed, which greatly improve the accuracy of the measurement system and laid the foundation of analyzing the accuracy of subgrade frost heaving data. At last, in order to verify the reliability and accuracy of the system in a cold environment, the temperature and illumination characteristic experiment of the system based on the high and low temperature test chamber in laboratory and track test platform in outdoor, the feasibility of the system scheme is verified by the experimental results.The subgrade frost heave remote monitoring system for high-speed railway is researched and developed by the thesis, set up a 3-month field test in Zhaodong boundary of Harbin-Qiqihar Intercity Railway. The system operates reliably and reaches the practical application of the requirements of high-speed rail. Through processing and analyzing the experimental data, the subgrade measurement point in Zhaodong boundary of Harbin-Qiqihar Intercity Railway certainly exists frost heave phenomena.