ANALYSIS ON STRENGTH SOFTENING OF argillite UNDER GROUNDWATER BY DAMAGE MECHANICS
Zhu Zhende1,Xing Fudong1,Wang Sijing1,2,Xu Weiya1
(1Research Institute of Geotechnical Engineering,Hohai University, Nanjing 210098 China) (2Institute of Geology and Geophysics,The Chinese Academy of Sciences, Beijing 100029 China)
Abstract:For the special geologic condition of 18 layers of argillite located in highwall slope of the intake in Longtan Hydropower Station Project,a study on the damage mechanism of the water-rock interaction is carried out. A series of uniaxial compression tests of the 18 layers of argillite with different water content are conducted in Rock Mechanics Rigidity Servo Testing System(RMT-150B). The test results show that the softening of compressive strength of argillite is not only closely related to its water content,but the time of being soaked in water. The effects of groundwater on rock strength and deformation are analyzed by theories of damage mechanics. Through introducing the volumetric change caused by rock dilatancy to the damage variable,the evolution equation of damage of rock meeting with water is established,which is closely related to rock stress state. The experiments demonstrate that it can well describe rock damage features caused by water,and so it provides the theoretic basis for analyzing landslide phenomenon caused by rainfall infiltrating into rock masses.