冻融循环下橡胶纤维加筋膨胀土(ESR) 的损伤特性

To investigate the effects of freeze-thaw cycles on the mechanical properties of Expansive Soil-Rubber Fiber (ESR), freeze-thaw cycle tests and consolidated undrained triaxial tests were conducted on saturated ESR. The variations in elastic modulus and damage of ESR were analyzed under different freeze-thaw cycles and confining pressure.The results indicate that: (1) Under the influence of freeze-thaw cycles, the elastic modulus of ESR decreases,while rubber fibers can mitigate the degradation of the elastic modulus caused by freeze-thaw cycles; (2) As strain increases,micro-defects in ESR develop into cracks that form rupture surfaces,ultimately leading to failure,with the damage variable approaching 1;(3) The initial damage variable in ESR is positively correlated with the number of freeze-thaw cycles. As rubber fibers serve as tensile elements, the damage evolution curves of ESR intersect successively, illustrating significant plastic characteristics in the later stages of shear; (4) Confining pressure can limit the development of micro-cracks in ESR, and the damage variable of ESR decreases with increasing confining pressure.The results validate the beneficial effects of rubber fibers in enhancing the freeze-thaw resistance of expansive soil,indicating a promising application prospect for backfill materials in frozen soil areas.