摘要
在具有冲击倾向性矿井的动载支护设计中,地震动对动态载荷的估算有重要作用。目前,国内外普遍采用半经验公式(scaling law)来估算质点峰值振动速度(PPV)。然而,此方法在实际估算地震动时忽略了地质和巷道开挖对地震动分布的影响。为更好地理解开挖对地震动在地下开挖边界分布的影响,基于笔者提出的适于开挖边界的非线性速度模型及FLAC/SPECFEM2D的耦合数值模拟方法,针对高质量及中等质量围岩体两种情况,对一地下采场的地震动分布进行了数值分析。研究结果表明,不同速度模型对地震动分布影响很大。考虑了围压及开挖影响的非均匀速度模型能够更好地模拟地震动在地下开挖边界附近的分布,且模拟的地震动在采场表面的放大作用与现场观测的放大现象具有很好的一致性。相比于高质量围岩体,当模拟的开挖采场围岩为中等质量围岩体时,采场开挖边界处具有更强的地震动及更广的地震响应。
Ground motion plays an important role in the estimation of dynamic loading for ground support design in burst-prone underground mines. A semi-empirical scaling law is often used for peak particle velocity（PPV） estimation; however, this method does not account the influence of geology and excavation effect on the ground motion in the dynamic support design. For better understanding the excavation effect of boundary distribution in the underground on the ground, the author puts forward a coupled numerical simulation method for non-linear velocity model and FLAC/SPECFEM2 D. Aiming at the high quality and fair quality rock masses, the numerical analysis of the ground motion distribution of an underground stope is carried out. It is found that different velocity models influence ground motion distributions near excavation boundaries greatly. Considering the effects of confining pressure and excavation on the nonuniform velocity model can better simulate the distribution of ground motion near the underground excavation boundary, amplification effect at excavation surface is captured, which agrees well with underground field observation results. Compared with the high quality surrounding rock mass, when the simulated excavation rock is fair quality rock mass, the excavation boundary of the stope has stronger ground motion and wider seismic response.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第11期3347-3354,3370,共9页
Rock and Soil Mechanics
基金
加拿大安达略省研究基金(ORF)项目(No.SUMIT)
加拿大国家自然科学与工程研究项目(NSERC)(No.RGPIN/249620-2011)~~
关键词
地震动
数值分析
波场模拟
PPV
ground motion
numerical simulation
wave field simulation
PPV
