Effect of heating on the excess pore water pressure of clay under undrained condition
WANG Kuanjun1，2，HONG Yi1，2，WANG Lizhong1，2，LI Lingling1，2
(1. College of Civil Engineering and Architecture，Zhejiang University，Hangzhou，Zhejiang 310058，China；2. Key Laboratory of Offshore Geotechnics and Material of Zhejiang Province，Zhejiang University，Hangzhou，Zhejiang 310058，China)
Abstract：Both the nuclear waste container and energy pile buried underground will elevate the temperature and change the stiffness and strength of the surrounding soil，leading to the possible deformation and potential instability of the geo-structure. Despite the extensive investigations into the effects of heating on mechanical behaviour of clay under drained condition，little attention has been paid to the influence of heating on the clay under undrained condition，which is frequently encountered in practice. This paper aims to study the pore pressure response of clay due to undrained heating through both theoretical and experimental investigations. A simplified model base on the framework of critical state soil mechanics was formulated to predict the development of the excess pore pressure of clay due to heating. Two types of clay(Zijingang clay and kaolin clay) were investigated experimentally using a temperature-controlled GDS triaxial testing apparatus. It was shown that the positive excess pore pressure was induced in both normally consolidated and overconsolidated clays subjected to undrained heating. The excess pore pressure increased with the temperature elevation，but decreased with the over-consolidation ratio(OCR). For the normally consolidated clay heated from 20 ℃ to 55 ℃，each temperature increment of 10 ℃ led to a 10% reduction in the effective stress. When the OCR exceeded 10，the heating induced excess pore pressure was almost negligible. The calculated results using the proposed model agreed reasonably with the experimental data，confirming the validity of the proposed model .
王宽君1，2，洪 义1，2，王立忠1，2，李玲玲1，2. 不排水升温条件下黏性土孔压响应[J]. 岩石力学与工程学报, 2017, 36(9): 2288-2296.
WANG Kuanjun1，2，HONG Yi1，2，WANG Lizhong1，2，LI Lingling1，2. Effect of heating on the excess pore water pressure of clay under undrained condition. , 2017, 36(9): 2288-2296.
ABUEL-NAGA H M，BERGADO D T，BOUAZZA A，et al. Volume change behaviour of saturated clays under drained heating conditions：experimental results and constitutive modeling[J]. Canadian Geotechnical Journal，2007，44(8)：942-956.
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2017, Vol. 36 
