Measurement and Analysis of High-speed Railway Subgrade Settlement in China: A Case Study

Subgrade is an important component of railway engineering construction, which supports the upper loads of tracks and trains. Subgrade stability directly affects the high-speed train safety and passenger comfort. With the rapid development of China's high-speed railway, it put a very high requirement for track smoothness, and thus the requirements of subgrade stability and deformation control become very stringent. In the paper, we studied the measurement methods, instruments, observation point set, observation frequency, precision and data prediction analysis etc. Using the subgrade settlement measured data of Beijing-Shanghai high-speed railway as a case study; we analyzed the relationship between the subgrade settlement and time, and applied hyperbolic model, exponential model and Poisson model to predict subgrade post-construction settlement. The results show that cumulative settlement of subgrade measuring point is 6.4 mm from the beginning to 118 th day after roadbed filling construction, and the sedimentation rate becomes steady at 0.001 mm/d. Comparative analysis shows that the hyperbolic model has the best fitting performance among the three curve regression models. And the predicted roadbed post-construction settlement of 3.22 mm has met the subgrade requirements for ballastless- track laying. Copyright © 2014 IFSA Publishing, S. L.