基于修正RMR法的深部岩体工程围岩质量评价研究

深部岩体工程具有典型的高地应力、高地温和高孔隙水压等特点,传统的RMR法对评价其围岩质量存在不足之处。通过考虑高压地下水和高地温对岩体力学性质的影响分别引入地下水和地温弱化系数,结合连续性细化方法对传统的RMR法中的岩石单轴抗压强度、岩石质量指标和节理间距等三个评价指标的评分标准进行了修正,获得了三个评价指标值与其对应分值之间的非线性连续回归方程。然后,根据岩体中地应力的大小及岩石强度特征定义了岩体损伤破坏危险度系数,建立了该系数与岩体质量评分修正值之间的对应关系。由此获得了比较符合深部岩体工程围岩质量评价实际的修正RMR法,并用实例表明了其评价结果的合理有效性。

Study on Evaluation of the Surrounding Rock Quality in Deep Rockmass Engineering Based on the Revised RMR Method

The deep rock engineering is characterized with high ground stresses,high earth temperatures and high pore pressures so that the traditional RMR method has many limitations in the evaluation of the quality of surrounding rock masses.The marking standards of 3 indexes including uniaxial compressive strength of rock,rock quality designation and joint space in the traditional RMR method are revised by combining the groundwater and ground temperature weakening factors defined considering the effect of the underwater of high pressure and high earth temperature on the mechanical characteristics of rock mass and a nonlinear continuous regressive function relating the values of 3 indexes to their marking values is gained.Then,the risk degree factor of rock mass damage is also defined on the basis of the value of the ground stress,rock strength and the corresponding relationship between their values,and the revised marking values of rock mass quality is built.Finally,an improved comprehensive RMR method is gained,which is appropriate for the evaluation of the surrounding rock quality in deep rock engineering.A case study shows that the revision method is reasonable and efficient.