Experimental studies and chemical analysis of water on weakening behaviors of deep soft rock
GUO Hongyun1，ZHAO Jian2，LIU Peiyu3
(1. Beijing Special Engineering Design and Research Institute，Beijing 100028，China；2. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，Beijing 100026，China； 3. China Academy of Building Research，Beijing 100013，China)
A series of fresh and dried rock samples from Daqiang coal mine were conducted by intelligent testing system for water absorption in deep soft rocks(a self-developed experimental system)，including tests of water absorption with pressure and without pressure. Then，uniaxial compressive strength tests were applied to obtain the characteristics of the strength weakening processes of the rocks after interacting with water in two different original states. The results demonstrated that the strength of deep soft rock after absorbing water decreased linearly with the increasing of water ratio. Comparing to the speed of the strength decline of rock specimens with and without water pressure，it could be found that the former was slower. The speed of the strength declining of dried rock samples was faster than that of fresh rock samples in the process of water absorbing. To better understand the mechanism for weakening of soft rocks in deep mines when absorbing a certain volumes of water，variances of chemical compositions of aqueous and microstructures of the rock samples were analyzed before and after water absorption tests，and the analysis demonstrated that：when interacting on water，clay minerals of the soft rock generally showed a series of interfacial phenomenon，and it caused the solution of soluble minerals and ionic exchange in the rock，and then it led to the dissolution and secondary of minerals. It can be concluded that the dissolution and secondary of minerals contribute to the variances of the concentration of ions and the strength softening of the rock specimens after absorbing water.
郭宏云1，赵 健2，柳培玉3. 深部软岩与水作用后的强度软化特性及化学分析[J]. 岩石力学与工程学报, 2018, 37(S1): 3374-3381.
GUO Hongyun1，ZHAO Jian2，LIU Peiyu3. Experimental studies and chemical analysis of water on weakening behaviors of deep soft rock. , 2018, 37(S1): 3374-3381.
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2018, Vol. 37 
