膨胀力驱动下硬黏土崩解机制研究——基于裂隙演变的试验分析OA

To investigate the evolution of disintegration behavior of remolded stiff clay under different swelling pressure conditions,expansive stiff clay samples with varying montmorillonite content and initial water content were prepared.The wetting process of samples was monitored throughout using a self-designed disintegration apparatus,and vertical swelling pressure was measured under constant volume conditions using a swelling permeameter.The results indicate that,at a given initial water content,increasing montmorillonite content enhances swelling pressure,amplifies expansion gradient during water infiltration,and promotes internal propagation of hydration cracks,accelerating disintegration.At a given montmorillonite content,higher initial water content reduces swelling pressure and permeability,lowers water infiltration,suppressing formation of heterogeneous expansion,and decreases disintegration rate.During hydration,the swelling potential and infiltration rate jointly control the formation of expansion gradient.The resulting tensile stresses induce hydration cracks,which compromise soil structural integrity and facilitate disintegration.Meanwhile,local disintegration provides preferential water infiltration channels to accelerate further soil expansion and hydration cracking until the completion of sample disintegration.Higher swelling pressure and lower initial water content both exacerbate disintegration of stiff clay.Engineering measures,such as optimizing soil composition and controlling water infiltration,can suppress swelling strain gradients and improve stability of expansive stiff clay.