【摘要】 汶川地震触发了大量的地震滑坡,其中滑坡岩体普遍出现了不同程度的震裂损伤现象。通过大光包滑坡现场大量的调查工作,揭示了该滑坡不同部位岩体的震裂损伤程度随埋深、地形地貌及岩性条件的不同呈现出一定的规律性,基于疲劳试验,从动力学的角度,分析了强震作用下滑坡岩体震裂损伤程度的影响因素。试验结果表明:上限应力是影响岩体震裂损伤程度的首要因素,应力水平是震动频率影响岩体震裂损伤程度的前提。并基于此分析得出,滑坡不同部位受控于埋深及地形地貌的差异,决定了其受到的地震作用力及应力状态各不相同,是影响岩体震裂损伤程度的动力因素;而滑坡不同岩性之间岩体结构的差异,导致其表现出不同的破坏特征,决定了在相同地震荷载下损伤程度各不相同,是影响岩体震裂损伤程度的内在因素;地震爆发初期,强烈的地震冲击作用力在短时间内对岩体产生的巨大损伤及岩体自身结构的缺陷,是造成岩体最终震裂损伤的基础。以上研究成果为强震作用下滑坡岩体的震裂损伤程度进行快速的定性评价提供了依据,并丰富了大光包滑坡滑带岩体碎裂化成因机制研究。更多还原

【Abstract】 Massive seismic landslides are triggered by Wenchuan Earthquake, and rock mass of the landslides is generally caught with different degrees of seismic damage. Field investigations of Daguangbao landslide are conducted, and certain regularity is obtained that the damage degree of different rock mass parts relates with buried depth, topography and lithology conditions. The influencing factors for the damage degree of shattered landslide rock mass under high seismic action are investigated through fatigue tests from the viewpoint of dynamics. The test results indicate that the upper limit stress is the primary factor to influence the damage degree of rock mass, and the stress level is the premise of vibration frequency which influences the damage degree of rock mass. Further analysis is proceeded, and it is found that different sites of landslide are controlled by the differences of buried depth and topography, resulting in different seismic forces and stress states, and they are the dynamic factor for the damage degree of rock mass. The differences in the structure of rock mass with different lithologies will lead to different failure characteristics and determine different damage degrees under the same seismic load, and they should be treated as internal factors. The strong damage of rock mass induced by strong impact force of earthquakes at the initial outbreak in a short period and the defects of rock mass structure are the basis of the final rock seismic damage. The aforementioned researches provide a basis for the rapid qualitative evaluation of seismic damage of rock mass under strong earthquakes, and enrich the formation mechanism of the rock mass fragments in Daguangbao sliding zone.更多还原