目前饱和边坡的强度折减法流固耦合分析是在总应力的静水压力差法基础上,通过调整浸润面位置、考虑材料浮力作用加以实现,未能解决强度折减过程孔隙水压力变化的情况。本文从岩土体固相介质强度参数(c、φ)与液相介质强度参数(孔隙水压力)相互关系出发,解释了固体骨架、自由水不同步的荷载传递过程,提出了有效应力的强度折减法、孔压增量近似确定方法,并在总应力静水压力差方法基础上给出了孔压增量—强度折减方法的实现过程。研究表明:孔压增量—强度折减方法计算的饱和边坡零孔隙水压力面升高0.34~0.44 m(4%~5%),与目前在涉水边坡流固耦合分析中按经验选取0.5 m的浸润面抬升值较为一致。
Now, on the basis of hydrostatic pressure difference of overall stress method, the fluid-solid coupling analysis of saturated slope by strength reduction limit analysis method is realized by adjusting soaking surface and using the action of levitating force, but the changing of pore pressure in the process of strength reduction is not resolved. In this paper, the asynchronous load transfer process on the solid skeleton and free water of soil-rock was explained from the relations of the strength parameters of solid phase (c,φ) and the strength parameters of liquid phase (pore water pressure). The effective stress strength reduction limit analysis method and the approximate determination method of pore pressure increment were advanced, and the pore pressure increment-strength reduction limit analysis method was realized on the basis of hydrostatic pressure difference of overall stress method. The research shows that zero-pore pressure surface increase 0.34~0.44 m(4%~5%)than the safety factors of strength reduction limit analysis method, this is close to the empirical value (0.5 m) that was used in the fluid-solid coupling analysis of saturated slope.
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