摘要
岩体中节理赋存位置隐蔽,参数获取难度大,研究不同节理参数变化对岩体强度的影响,有利于在节理测量中有针对性地提高测量精度,并找出对岩体强度弱化最明显的参数.基于等效岩体技术,研究了云南省光山1号隧道岩体节理离散裂隙网络(DFN)参数倾角均值、倾角标准差、节理尺寸、节理尺寸分布幂和节理密度对岩体表征单元(REV)单轴抗压强度的影响,分析了岩体强度对各参数的敏感性.研究结果表明:岩体强度对倾角均值有最大的敏感性,因此在节理测量中需重点加强对倾角的勘查;节理密度增大对岩体强度的弱化作用最明显,因此,当节理密度增大时,需及时调整施工方案并提高支护强度.该研究为节理勘查重点提供了参考,也为节理参数变化时隧道稳定性的快速预测提供了依据.
The location of the joints in the rock mass is concealed,and the parameter acquisition is difficult.Investigating the effect of different parameters of joints on the strength of rock mass is helpful to improve the measurement accuracy of joints and to find out the parameters that have the greatest effect on the weakening of the rock mass.Based on the equivalent rock mass technology,the influence of the Discrete Fracture Network(DFN)parameters of jointed rock mass on the uniaxial compressive strength of the Representative Elementary Volume(REV)were studied in Guangshan No.1 tunnel,Yunnan province.These parameters include mean dip angle,standard deviation of dip angle,joint size,the power of joint size distribution,and joint density.The sensitivity of these parameters on rock mass strength was also analyzed.The results show that:the strength of rock mass has the greatest sensitive to the joint mean dip angle.So it is necessary to strengthen the survey of dip angle.Increased joint density has the strongest weakening effect on rock mass strength.When the joint density increases,it is necessary to adjust the construction plan in time and improve the support strength.This study provides a reference for the key points of joint exploration and also provides a basis for rapid prediction of tunnel stability when the joint parameters change.
引文
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