Mechanism Study On Drift Stoping Operation Considering Residual Strength Of Rock Masses

Abstract:Based on engineering geological survey, rock mechanical property test, theoretical modeling and numerical simulation, the mechanical mechanism of drift stoping operation which considers the properties of residual strength of rock mass was researched. In this dissertation, several significant research findings were obtained, which are shown as follows:(1) According to engineering geological survey and rock mechanical property test, the physical mechanics parameters of rock mass were acquired. And, the rock quality evaluation and classifaction system was established.(2) The visualization of two dimension random joint network was realized based on the geological raw data and Monte Carlo random theory.(3) Base on the principle that material micro-unit strength obeys Weibull Distribution, statistic damage softening-hardening constitutive model of rock mass was established. by introducing effective damage rate parameter which demonstrates the residual strength of rock mass. The proposed constitutive model not only demonstrates damage randomness, strain softening process of rock mass but also reflects its strain hardening regularity after the peak period. Then, back analysis, the statistic damage softening-hardening constitutive model which agrees with experimental results of rock mass in Jiaojia Gold Mine was also proposed.(4) After numerical simulation(FLAC3D)and analyzing the influences between the plastic zone volume, roof sedimentation, stress, displacement, and the rise-span ratio, the mechanical mechanism of drift stoping operation(which considers the properties of residual strength of rock mass) was researched.