Study on Mechanical Properties Subjected to Monotonic and Dynamic Loads of Loessal Soil in Songyuan City

Abstract

In this paper taking loessal soil of Songyuan in Jilin province as the research object，static and dynamic triaxial tests were conducted to investigate the effects of water content and confining pressure on dynamic characteristics of loessal soil. The test results showed that: (1) Under monotonic loading, the deformation of loessal soil exhibits two situations: strain hardening and strain softening, and the deformation behavior is influenced by water content and confining pressure. The static strength decreases with the increase of water content and increases with the increase of confining pressure. (2) The cumulative plastic strain of loessal soil under dynamic load exhibits three modes: plastic shakedown, plastic creep, and incremental collapse. Existence of critical dynamic stress results in significant differences in the cumulative plastic strain of soil. (3) The cumulative plastic strain of soil samples is influenced by water content, confining pressure, and dynamic stress amplitude, low confining pressure, high water content, and high dynamic stress amplitude are adverse to the plastic stability of loessal soil. Based on experimental results, predict the range of critical dynamic stress. The research results have reference value for the evaluation of dynamic deformation stability of settlement of subgrade constructed in the loessal soil.