【摘要】 基于汶川大地震形成的崩塌滑坡数量多、分布密度大、影响面积大等特点,分析复杂结构斜坡地震力作用下的破坏机制,给出斜坡中某点在微震和强震作用下的应力–应变曲线。指出在地震力作用下斜坡会产生附加应力,其与原始应力叠加形成总应力,当总应力超过岩体的抗拉强度时发生拉张破裂,并给出拉张破裂的判据。用有限元模拟了单一弱面斜坡强震作用下的拉张破裂过程。结果表明:当第一主(拉)应力大于等于岩石的抗拉强度时,岩体发生拉张破裂,不能再承受拉力,但可承受压力;如果总应力状态满足塑性屈服准则,则发生剪切破坏;在地震动力作用过程中,拉张破裂区不断累加,即在松动区的松散程度和松散范围都在增大;在地震动力作用下,含有弱面的斜坡很容易沿弱面发生拉张破裂。更多还原

【Abstract】 Based on the characteristics of collapse and landslide induced by Wenchuan earthquake that the quantity,the distribution density and the influential area,etc.are large,the damage mechanism of the complex structural slope is analyzed under strong earthquake,and the different stress-strain curves of some points in slope are given under microseism and strong earthquake.It is pointed that slope will generate additional stress under the effect of earthquake.The superposition of the additional stress and the original stress forms the total stress.When the total stress is larger than the tensile strength of the rock,tensile fracture occurs.The tensile fracture criterion is given.The finite element method is used to simulate tensile fracture process of slope with single weak plane under strong earthquake.The following conclusions can be drawn.When the first principal(tensile)stress is greater than or equal to tensile strength of rock,it cracks and can not bear tensile stress but compressive stress;if the total stress state meets the plastic yield criterion,shear failure occurs;the tensile fracture region cumulates continuously during earthquake dynamic,that is,the loose degree and the loose range become increase;and the slope containing weak plane can easily crack along the weak plane under earthquake.更多还原