【摘要】 "5·12"汶川大地震造成了大量山体斜坡震裂变形和破坏现象,为深入研究其力学机理,通过实例详细调查及地震中体波效应和面波效应的深入分析,认为地震中地震波的作用使山体斜坡表部岩土体尤其是坡肩部位受到量值和方向不断变化的拉张应力作用,该作用在垂直平面内表现为全方位动态变化特点,导致坡肩岩土体具有旋转倾倒和正、反拉作用;与此同时在坡体内部伴随出现潜在剪动作用力及岩土体的开裂和压碎现象,尤其在潜在滑动面上剪切作用力更为集中;此外坡体表面还受到鼓胀拉力和扭力的共同作用。据此可将地震波作用效应划分为4种重要表现形式,即拉-剪破裂效应、界面动应力效应、潜在的楔劈效应和超空(孔)隙水压力激发机制。分析结果与实例及振动模拟结果一致。研究成果可为灾后重建和防灾减灾提供参考。更多还原

【Abstract】 On the basis of the phenomena of slope shattered deformation and failure after 5·12 Wenchuan great earthquake,the effects of body wave and surface wave in the earthquake are analyzed,and the mechanical mechanism of slope shattered deformation are studied.It is considered that the effect of seismic waves caused the alternate action of the tension stress with values and direction constantly changing acted on the rock and soil mass of slope surface layer,especially on the slope shoulder,the characteristic on perpendicular plane showed overall dynamic change and resulted in the rock and soil mass on shoulder appeared revolution-dump,positive and inverse tension action.Meanwhile,the following shear action,cracking and crushing occurred.The shear action was more concentrated on slide surface.In addition,the bulge tension and torsion forces acted together on the slope surface also.In this paper,seismic wave effect is divided into four kinds of forms: the tension-shearing rupture effect,the interface dynamic stress effect,the potential wedge splitting effect,and the super interstitial hydraulic or pore water pressure excitation mechanism.The analysis results are well in accordance with field phenomena and the result of vibration simulation model,provided an important guide for the post-disaster reconstruction and disaster prevention and mitigation.更多还原