【摘要】 针对开挖导致岩体应力场改变、扰动深度估算这一岩体力学的难题,从岩体应力场的变化出发,结合岩体结构面力学特点,推导出岩体卸荷破坏导致岩体破坏的判别公式,为岩体强开挖扰动带深度的确定推导出理论估算公式。以小湾坝基岩体开挖为例,结合判别公式和数值分析结果,对坝基岩体的强开挖扰动带、弱开挖扰动带及应力调整带进行了分析。结果表明,在坝基底部,强开挖扰动带深度为3~5 m,弱开挖扰动带深度为4~10 m,应力调整带深度为10~25 m,其结果与现场钻孔电视探测结果基本吻合。更多还原

【Abstract】 The stress will be redistributed in the rock mass after excavation,and the deformation of rock mass will be produced to balance the stress adjustment,then the mechanics properties of the rock mass near to the excavation surface will be deteriorated greatly.The formula for evalu-ating the excavation disturbed zone is derived with the method of rock stress redistribution and combined the characteristics of the structural surface of rock masses.Taking Xiaowan dam base excavation as an example,the heavy excavation disturbed zone and the weak excavation disturbed zone are calculated combined with the evaluating formula and numerical simulation.The numer-ical analysis results show that the heavy excavation disturbed zone is about 3~5 m,the weaken excavation disturbed zone is about 4~10 m,and the stress readjusted zone is about 10~25 m.The evaluating results are very close to the detection ones.1 tab,4 figs,19 refs.更多还原