Dynamic Response Characteristic of Layer Interface of Soft Soil Subgrade with Dry Crust Covering and Its Engineering Application

Abstract

AbstractConsidering the obvious wave impedance difference between dry crust and soft, the phenomenon of dynamical stress mutation at the hard-soft soil interface, which is a specific performance of shell effect of dry crust in dynamic scope, is revealed by the transmission coefficient based on stress-wave theory. The attenuation law of vertical dynamic stress peak in subgrade soil under vehicle load is obtained by numerical simulation. Based on the negative exponential function characteristic of an attenuation curve, a transfer coefficient at soil layer interface is derived. This coefficient can synthetically represent the law of dynamical stress mutation. The corresponding calculation method and application range of the transfer coefficient are offered. This calculation method has simpler processing and higher precision than existing methods based on monitoring data verification. By practice validation of expressway engineering, the mechanical state of subgrade soil can be correctly evaluated, and its re...