Chemo-mechanical coupling model for overconsolidated saturated saline clay and its validation
WANG Liye1，2，ZHOU Fengxi1，MU Zhanlin1，WAN Xusheng3，WU Daoyong4
(1. School of Civil Engineering，Lanzhou University of Technology，Lanzhou，Gansu 730050，China；2. School of Civil and Hydraulic Engineering，Ningxia University，Yinchuan，Ningxia 750021，China；3. School of Civil Engineering and Geomatics，Southwest Petroleum University，Chengdu，Sichuan 610500，China；4. Key Laboratory of Karst Geological Resources and Environment，Ministry of Education，Guizhou University，Guiyang，Guizhou 550025，China)
Abstract：To accurately predict the influence of osmotic suction on the mechanical behavior of overconsolidated saturated saline clay，an elastoplastic model considering the effect of osmotic suction is established to provide a theoretical basis for predicting the chemo-mechanical coupling behavior of saturated saline clay. Based on the theoretical foundation of the unified hardening(UH) model，the model is established to consider simultaneously the osmotic suction，degree of consolidation and chemo-mechanical coupling effect by introducing the osmotic efficiency parameter and coupling stress，as well as obtaining the theoretical expressions for the overconsolidation ratio and osmotic suction. From verification results，the new model has the following properties. (1) The effects of deformation softening and strength hardening induced by osmotic suction can be described with the help of the concept of coupled stresses. (2) The chemo-mechanical coupling behavior of saturated saline clay can be accurately predicted for different stress histories，drainage and saline conditions with the addition of only two parameters. (3) The relationship between the overconsolidation ratio of saturated saline clay and osmotic suction can be revealed，as well as the interaction mechanism of their chemo-mechanical coupling behavior. In addition，the results provide a valuable theoretical basis for the chemo-mechanical coupled analysis and behavior prediction of clay under chemical environment.
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