有限元强度折减法在实施过程中往往要根据不同的折减系数手工修改输入文件,并不断进行试算,过程较繁琐。为了简化计算过程,提高计算效率,在有限元强度折减法的基础上,结合ABAQUS提供的场变量,提出一种适用于有限元强度折减计算的新方法——基于场变量的有限元强度折减法。通过在ABAQUS中设置岩土体黏聚力与内摩擦角为场变量的函数,场变量为增量步时间t的函数,从而通过控制增量步时间t实现黏聚力与内摩擦角的折减,通过一次计算即可求得边坡的安全系数,无需手工修改折减系数反复试算。结合有关文献对该方法用于边坡稳定分析的可行性进行了验证,并与二分法确定安全系数的计算效率进行了比较。结果表明:该方法求得的安全系数是有效可靠的,用于边坡稳定性的计算是可行的,简化了有限元强度折减法的计算过程,提高了计算效率。
In the implementation of strength reduction finite element method (SRFEM), the input file will be modified by hand based on various reduction factors to do trial calculation, the process is trivial. In order to simplify the computational process and improve efficiency, on the basis of SRFEM, combined with field variable provided by ABAQUS, a new technique for strength reduction calculation is presented-field variable based strength reduction finite element method. Cohesions and internal friction angles of rock and soil mass are assigned as functions of field variable in ABAQUS; field variable is assigned as a function of step time t, the cohesions and internal friction angles can be reduced with the increase of t, the safety factor of slope can be obtained in a single simulation process, which avoid modifying of input file and without repeating the trial calculation. Combined with some literatures, the validation of this technique for slope stability analysis has been done; the computational efficiency is compared with bisection method in the determination of safety factor. The results show that: the safety factor obtained by this method is effective and reliable; this technique is feasible for slope stability analysis; this technique simplifies the process of calculation; the efficiency of calculation is improved.