Numerical simulation of settlement of soft soil foundation under fast metro train loads

The soft soil foundation will have settlement under the action of subway train load, such as post-construction settlement and uneven settlement, which will affect its service performance and service life. In order to study the settlement characteristics of soft soil foundation under different speed subway train loads, the finite element software ABAQUS is used to establish a three-dimensional dynamic finite element model. The settlement laws of the soil at normal speed (80km/h) and faster speed (120 km/h) are compared and analyzed, and by combining with the theoretical experience, the formula is modified to predict the post-construction settlement of the subway operation. The results show that, the greater the running speed of the train, the greater the fluctuation of the soil under the tunnel, the more obvious the distribution of the wheel-rail of the settlement curve, and the greater the lateral influence range of the surface settlement trough, which is about 4.5 times the diameter of the tunnel at both sides of the tunnel axis, but its post-construction settlement decreases with the increase of subway speed. The influences of vertical settlement of the soil under the action of fast subway train is 3 times the tunnel diameter. After the operation of the line, the settlement is about 57 mm in one year, accounting for 30% of the accumulated settlement, and the accumulated settlement after 20 years is about 190 mm..