Compressibility-undrained shear behavior relationship for reconstituted sandy clays
摘要
The sandy clay consisted of hosted clay and sand particles. Isotropically consolidated undrained triaxial compression shear (ICUTCS) tests were performed on two clays with varying sand fractions (SF = 0–60%) and initial water contents of hosted clays (w0(hosted clay) = 1.2-1.4wL(hosted clay), where wLhosted clay is the liquid limit of hosted clay). The void ratio of hosted clay (ehosted clay) and undrained shear strength (Su*) curve is used to establish the compressibility (ehosted clay -pc΄) and shear strength (Su*- pc΄) relationship for reconstituted sandy clays. pc΄ is the isotropic consolidation stress. SF affects ehosted clay, further influencing Su* of sandy clays. At the same w0(hosted clay) and pc΄, when SF ≤ SFthreshold, Su* of sandy clays is equal to that of reconstituted clays and the sandy clay is sand particles dispersed distribution stage; when SF>SFthreshold, as SF increases, Su* of sandy clays gradually decreases due to the direct contact or clayey bridges between sand particles and the sandy clay is in structural effects of sand particles existing stage. SF, pc΄ and w0(hosted clay) affect Su* of sandy clays by changing ehosted clay. The Su*-e relationship of sandy clays is dependent on SF and wL(hosted clay). The wL(hosted clay) can consider types of hosted clays. An empirical method for predicting Su* in reconstituted sandy clays during different pc΄ is presented. The predicted values are almost identical to the measured data, with errors within ± 10%.