滑坡关键块力学行为及力传递特征和不同应力状态的稳定系数研究

STUDY OF MECHANICAL BEHAVIORS OF KEY BLOCKS AND CHARACTERISTICS OF FORCE TRANSMIT AND STABILITY COEFFICIENT OF DIFFERENT STRESS STATES OF LANDSLIDES

分析滑坡关键块的力学行为及滑坡力的传递特征,研究滑坡在摩阻力没有折减条件下,滑坡条块下滑力、摩阻力和推力的相互关系,指出滑坡条块在下滑力、摩阻力相等(即推力矢量和为0)时,该条块处于临界应力状态。研究推移式滑坡条块间推力所表征的力学特征,进而提出滑坡条块处于不同推力条件下,条块间推力测量的基本特征:处于残余应力状态和破坏后区应力状态条块间推力测量值逐渐减小或增大(即力测量可以为负值或正值),处于临界应力状态前条块间的推力测量值逐渐增大(即力测量为正值),该结果对滑坡监测具有指导作用。研究现行滑坡稳定系数的计算方法,针对临界应力状态、破坏后区应力状态和残余应力状态及其混合应力状态,以剩余推力法证明现行临界应力状态法计算滑坡稳定系数不是最小值,而取残余应力状态力学参数计算的稳定性系数为最小值,并证明了它们之间的相互关系。

The mechanical behaviors of key blocks and characteristics of force transfer of landslides were analyzed. The interactions among forces of sliding,friction and thrust were investigated assuming the anti-sliding forces were not reduced. The slice is at the critical stress state if the sliding force is equal to the friction. Representative characteristics of thrust between the analyzed slices were studied. The difference of the thrust between slices defines the different stress states. If the stresses of slices are between the residual stress state and the peak stress state,the trust change decrease or increase gradually（the measured values of the thrusts can be negative or positive）. If the stresses of slices have not reached the peak state,the thrust increases gradually（the measured values of the thrusts can only be positive）. A relationship between the coefficients of stability considering the＆amp;nbsp;different stress states was derived. The coefficient of stability calculated with the conventional stability analyses in terms of the critical stress state of landslides was not the smallest one, while that calculated in terms of the residual stress state turned out to be the smallest one,considering three different stress state（the critical stress state,the failure stress state,the residual stress state and the mixed stress state）.