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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。
Wenchuan earthquake triggered a large number of earthquake landslides, in which the rock mass generally appeared different degrees of shock damage. Based on a large amount of investigation on the site of Daguangbao landslide, it reveals that the damage degree of rock mass in different parts of the landslide shows some regularity with depth, topography and lithology conditions. Based on the fatigue test, The influencing factors of the degree of earthquake damage of landslide rock mass under strong earthquake are analyzed. The experimental results show that the upper limit stress is the primary factor affecting the degree of rock fragmentation and the stress level is the precondition of the vibration frequency affecting the degree of rock fragmentation. Based on this analysis, it is concluded that different parts of the landslide are controlled by the difference between the buried depth and the topography, which determines that the seismic forces and stress states they are subjected to are different, which are the dynamic factors that affect the degree of rock fragmentation damage. The difference of rock mass structure between different lithologies results in different failure characteristics and determines the different damage degree under the same seismic load, which are the intrinsic factors that affect the degree of rock fragmentation damage. In the early stage of earthquake, Of the earthquake impact force in a short time on the huge damage to the rock mass and the structural defects of the rock itself is the basis for the final rock damage caused by the rock. The above research results provide a basis for rapid qualitative evaluation of the degree of earthquake damage of landslide rock mass under the action of strong earthquakes and enrich the genetic mechanism of rock mass fragmentation in Daguangbao landslide zone.