基于邓肯张模型多参数协调的强度折减法研究

简要介绍了邓肯张模型, 结合大量的三轴实验数据对邓肯张模型进行了分析, 建立了强度参数与变形参数之间的等价关系, 进而提出一种考虑变形参数与强度参数协调折减的强度折减法。分析了不同折减方案对尾矿坝安全系数和塑性区分布的影响, 得出与单纯折减c,φ值相比, 协调折减R_f,K,n与c,φ的方案得到的位移场偏大, 而协调折减K_b,m与c,φ的方案得到的位移场偏小, 多参数协调折减的方案得到的位移场是一种折中的结果。同时, 多参数协调折减方案可以消除模型底部部分不合理的塑性区, 计算的安全系数结果最小, 有利于工程的稳定性评价。

Strength Reduction Method Based on Duncan-Chang Model with Comprehensive Consideration of Multiple Parameters

After a brief introduction, Duncan-Chang model was analyzed with a large number of triaxial test data and an equivalent correlation between strength and deformation parameters was obtained. Then, the strength reduction method with parameters of strength and deformation taken into the comprehensive consideration was proposed. Based on the analysis of the influence of different reduction scheme on the tailings dam in terms of safety factor and its plastic zone distribution, it is found that the scheme with a coordinated reduction between R_f , K, n and c,φ, compared to the scheme with the simple reduction of c and φ, resulted in a larger displacement field, while the scheme with a coordinated reduction between K_b,m and c,φ brought in a small displacement field. Consequently, the coordinated reduction among multiple parameters can lead to a compromised result, which can also eliminate unreasonable plastic zone at the bottom of the model. The calculated safety factor seems to be the minimum, indicating such method is conducive to engineering safety evaluation.