EPS混合土的动模量和阻尼比特性

发布时间：2018-04-24 02:16

本文选题：EPS混合土 + 动应力　；参考：《岩土工程学报》2017年02期

【摘要】：作为一种路堤填料,EPS混合土在动力荷载作用下的模量和阻尼比是进行路堤动力稳定性分析的重要参数。开展了15个循环扭剪试验研究EPS混合土的动力特性,分析了EPS混合土的骨干曲线、模量以及阻尼比特性,重点讨论了配合比和初始固结条件的影响。结果表明,EPS混合土具有典型的动力非线性特征,受水泥土强度和初始应力状态控制;EPS掺入比对混合土的初始剪切模量几乎无影响,但土体进入非线性阶段后,EPS颗粒对混合土强度的削弱作用明显;EPS颗粒与水泥土间薄弱接触面的动力行为导致"结构阻尼"效应,是混合土阻尼机制的重要组成;EPS混合土的初始剪切模量随试样初始小主应力增大而增大,其模量衰减特性与初始小主应力和EPS掺入比显著相关。基于试验结果,给出了描述EPS混合土骨干曲线、模量衰减和阻尼比增长特性的经验模型。
[Abstract]:As a kind of embankment filler EPS mixed soil modulus and damping ratio under dynamic load is an important parameter for dynamic stability analysis of embankment. Fifteen cyclic torsional shear tests were carried out to study the dynamic characteristics of EPS mixed soils. The backbone curves, modulus and damping ratio of EPS mixed soils were analyzed, and the effects of mix ratio and initial consolidation conditions were discussed. The results show that the EPS mixed soil has typical dynamic nonlinear characteristics, and the initial shear modulus of the mixed soil is almost unaffected by the ratio of EPS mixing ratio controlled by the strength and initial stress state of the cement soil. But when the soil enters the nonlinear stage, the strength of mixed soil is weakened by EPS particles. The dynamic behavior of the weak interface between EPS particles and cement soil leads to the "structural damping" effect. The initial shear modulus of EPS mixed soil increases with the increase of initial small principal stress, and its modulus attenuation characteristic is significantly related to initial small principal stress and EPS ratio. Based on the experimental results, an empirical model is presented to describe the characteristics of the backbone curve, modulus attenuation and damping ratio growth of EPS mixed soil.
【作者单位】：南京工业大学城市地下空间研究中心;南京工业大学岩土工程研究所;
【基金】：国家自然科学基金项目(51578286)
【分类号】：U416.12

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