邓肯模型参数整理研究.doc

邓肯模型参数k、n、Rf整理方法研究 张 波 （西安地质矿产勘查开发院，陕西，西安710100.） 摘 要：ε1/（σ1-σ3）~ε1关 键 词：Duncan model parameters k, n, Rf sorting method/Zhang Bo,(Xi’an Institute of Geological And Mineral exploration,Xi’an Shannxi710100,China) Abstract: The four kinds of gravel material for triaxial CD tests, using all methods (all test points), 70 - 95 method (stress level 70 ~ 95% of test points) and section method (small strain test point demand parameter k , n, the stress level of 70 to 95% of the test points request parameter Rf) are three ways to strike a Duncan-Chang model parameters k, n, Rf, and the use of three methods of parameter fitting to strike a strain-strain curves and test curves comparative study of the pros and cons of different methods to strike.The results showed that: Triaxial stress-strain curve does not fully comply with the hyperbolic relationship, ε1 / (σ1-σ3) ~ ε1 curve showed a clear bilinear, the turning point is about 1% strain; carbide material although no viscous soil, but its cohesion is not zero, the project should be properly taken into account; all law and to strike the law from 70 to 95 parameter fitting curve is more consistent with the experimental curve, fit better, but considering the stress strain-softening problems, 70 to 95 law parameters can strike a better simulation curve, although the parameters of sub-strike law in line with the physical and mechanical sense, but to strike a parameter k, n using only a small strain of test points, the proposed curve together with the experimental curves vary greatly, the stress level is recommended 70 to 95% of the test points to strike Duncan-Chang model parameters k, n, Rf. Keywords: triaxial tests; carbide material; Duncan-Chang model; stress - strain 1 引言 Duncan-Chang模型[2]是基于Kondner[3]应力应变符合双曲线的假定下建立的，以广义虎克定律为基础，具有参数简单，物理意义明确，能反映土体变形的主要特点，且能够通过室内常规三轴CD试验就可以求取模型参数。近些年来国内很多学者对Duncan-Chang模型进行了研究，包括对模型的改进[4-6]，模型对不同土料的适用性[7-10]，模型参数对有限元计算结果的敏感性[11-12]及模型参数的求取[13-15]等几大方面，对其有了全面的了解，工程技术人员对不同土料的模型参数的范围有了基