软土动应力-应变曲线复合指数-正弦模型

Composite exponential-sine model for dynamic stress-strain curve of soft soil

软土动应力-应变曲线(DSSC)模型是土动力学研究中的一个重要课题。结合软土DSSC的试验规律,分析了其数学模型应具有的基本性质。以最终动强度和初始切线模量为基本参数,对传统双曲线模型和指数模型进行了数学分析。引入动强度因子的概念,揭示了两传统DSSC模型的缺陷。提出了一个软土DSSC复合指数-正弦模型,该模型是一个单调递增、外凸且有极限值的函数。数学分析表明,新模型克服了传统模型的不足,两传统模型均是新模型对应的特例。最后,给出了模型参数的确定方法,通过实测数据拟合验证了新模型的正确性。

Mathematical modeling of dynamic stress-strain curve（DSSC）is important to the study of dynamic behavior of soft soil.Based on an analysis of measured data,the required primary behaviors of DSSC model are analyzed.Ultimate dynamic strength and initial tangent modulus are used to analytically examine the conventional DSSC models,hyperbolic model and exponential model,and a dynamical stress index is proposed and adopted to show the shortcomings of these two models.A composite exponential-sine model of three parameters,or a monotonically increasing and convex function with an upper bound,is developed,and an approach for determinination of model parameters is presented.Mathematical analysis shows that this model can overcome the shortcomings of the two conventional models that are two special cases of the new model,and the modeling results agree with the measured data.