Study On Method For Measuring Surface Subgrade Settlement In High-speed Railway

With the rapid construction of high-speed railway, subgrade settlement control and settlement measurement have faced increasing demands and challenges. The existing measurement methods of subgrade settlement have some inevitable disadvantages that limited their application in high-speed railway subgrade settlement measurement. The purpose of this project is to develop a monitoring system that can measure settlement remotely, automatically and accurately in high-speed railway subgrade settlement.This paper designs a monitoring system, using infrared LED, telephoto lens and linear CCD for measuring the surface of subgrade settlement. The main contents include:1. Describe the current development of China’s high-speed railway and the composition of subgrade settlement, and elaborate the existing settlement measurements at home and abroad. Then compare the advantages and disadvantages of each method.2. Introduce the principle of optical method for measuring surface subgrade settlement, and design a variety of monitoring programs. Then compare their advantages and disadvantages.3. A optical path based on telephoto lens is designed to improve the accuracy of the measurement system is. And the optical path has been simulated and optimized by ZEMAX.4. Describe hardware selection, circuit design and software processing algorithms of the measurement system.5. Build the surface subgrade settlement measurement system in the laboratory to simulate the surface subgrade settlement measurement experiment. And the resolution and stability have been proved.