Experimental research on fatigue performance of cement-lime improved soil in stress field

SI Wenqi; ZHANG Xin; GAO Tao; WANG Junjie; CHEN Qifan; WANG Jing; ZHAO Yuehang

doi:10.3969/j.issn.1672-0032.2024.03.010

Abstract：In order to obtain the fatigue performance of improved soil under different influencing factors,cement and lime are used as cementitious materials to prepare the improved soil.By analyzing the mass fraction of cementitious materials,curing age,stress level,and other factors in the improved soil through cyclic loading tests,the influence of these factors on the unconfined compressive strength,fatigue strength,and fatigue life of the improved soil is studied to establish a regression equation for the fatigue life of the improved soil.The results show that the mass fraction of cementitious materials has a significant impact on the fatigue failure strength and fatigue life of the improved soil.The unconfined compressive strength increases with the increase in the mass fraction of cementitious materials.The fatigue failure strength and fatigue life of the improved soil at different curing ages are positively correlated with the mass fraction of cementitious materials.For different curing ages,the critical cyclic fatigue stress ratio of cement soil decreases with the increase in the mass fraction of cementitious materials,while for lime soil at the same age,the critical cyclic fatigue stress ratio is less affected by the mass fraction of cementitious materials compared to cement soil.The relationship between curing age and the fatigue strength and fatigue life of cement soil is exponential,while for lime soil,it is quadratic.The critical cyclic fatigue stress ratio of the improved soil decreases with the increase in curing age.The fatigue life of the improved soil is longer when the stress amplitude and mean stress of cyclic loading are smaller,and vice versa,the fatigue life is shorter.