A model for predicting the mechanical properties of frozen moraine soil under impact loading

Abstract

The frozen moraine soil is geographically distributed across the Qinghai-Tibet Plateau and its surrounding areas, serving as a fundamental substrate for engineering projects such as the Sichuan-Tibet Railway and the China-Pakistan Highway. As an economical and efficient construction technique, blasting is a commonly employed in these projects. Understanding the dynamic mechanical response, damage, and failure characteristics of moraine soil is crucial for accurately predicting the impact of blasting. Therefore, this study utilizes the Split Hopkinson Pressure Bar (SHPB) equipment to conduct impact tests on moraine soil under different temperatures and strain rates. Additionally, a model for predicting the dynamic mechanical response of frozen moraine soil has been proposed based on peridynamic theory, decohesion damage theory, and the ZWT model, in which the debonding damage and the adiabatic temperature rise are considered. This model focuses on considering the bonds between different substances within frozen moraine soil. By defining the mechanical response of these bonds, the impact deformation mechanism of frozen moraine soil is unveiled. Within this, the modeling of ice-cemented bonds contributes to a deeper understanding of the crack propagation characteristics in frozen moraine soil. The model prediction results demonstrate its capability to predict various aspects of the dynamic response of frozen moraine under impact loading, including the macroscopic stress-strain behavior, the mesoscopic crack initiation and propagation, and the influence of adiabatic temperature rise on the damage mechanism, as well as evaluate the damage state of frozen moraine soil under impact loading.