A simple method for predicting pressure transients in high-speed subway tunnel based on train reflected waves

The aerodynamic pressure transients caused by high-speed subway trains entering the tunnel can usually be simulated with high accuracy using three-dimensional compressible numerical simulation methods. However, these methods often require high computer resources, complex pre-processing and post-processing processes. For practical engineering design, it is difficult to use these methods to achieve fast and simple calculation. In this paper, a train wave signature method (TWS method) proposed by previous scholars in high-speed railroad tunnels was introduced, the principles of the method were explained in detail and a generalized computational method for predicting the pressure time history was established. Additionally, an improved TWS method based on the reflected waves from trains was proposed by analyzing the reflection mechanism of pressure waves encountering trains during the trains passing through the tunnel, and the calculation results were verified by using field measurements and three-dimensional numerical simulations. The results show that the improved TWS method has better accuracy compared to the TWS method. Furthermore, this paper presents a smoothing method to enhance the optimization of the improved TWS method and extends its feasibility for pressure gradient calculation.