基于颗粒接触度分析的黄土起始动应力估算方法  

Estimation method of initial dynamic stress of loess based on particle contact density

作　　者：郭鹏[1] 孙军杰[1,2] 孙昱 彭立顺 田文通 GUO Peng;SUN Junjie;SUN Yu;PENG Lishun;TIAN Wentong(Key Laboratory of Loess Earthquake Engineering,Lanzhou Institute of Seismology,CEA,Lanzhou 730000,China;Geotechnieal Disaster Prevention Engineering Technology Researeh Center of Gansu Province,Lanzhou 730000,China;Qianling Comprehensive Seismic Station,Earthquake Administration of Shaanxi Province,Qianxian 713300,China)

机构地区：[1]中国地震局兰州地震研究所黄土地震工程重点实验室,甘肃兰州730000 [2]甘肃省岩土防灾工程技术研究中心,甘肃兰州730000 [3]陕西省地震局乾陵综合地震台,陕西乾县713300

出　　处：《地震工程与工程振动》2018年第5期161-170,共10页Earthquake Engineering and Engineering Dynamics

基　　金：中国地震局地震预测研究所基本科研业务费项目(2017IESLZ06;2013IESLZ05);国家自然科学基金项目(51779234)~~

摘　　要：为简约合理地估算黄土动残余应变的起始动应力,提出土颗粒接触度均值距离的概念及其表达形式,结合表征土体动力耐受特性的应力比参量,构建利用黄土相关物性参量估算起始动应力的方法。结果表明:颗粒接触度均值距离能够反映土体细观尺度的接触特征,与土体抗剪强度具有良好的相关性;以抗剪强度为纽带,可建立考虑细观尺度参量的黄土起始动应力估算方法;利用等效循环地震剪应力,其形式可求算地震作用下的黄土起始动应力。得出颗粒接触度均值距离的实验工作量,显著少于抗剪强度参量,具有更佳的便利性;估算方法所得计算结果与试验数据较为一致,在误差控制方面表现较佳,具有合理性。To propose an estimation method for the initial dynamic stress of loess dynamic residual strain with the simple and reasonable meaning,we introduced the concept of average distance to describe particle contact density and established its mathematical expression,then applied the stress ratio that figures the endurance capacity of loess to resist external dynamic loadings. We also put forward an estimation method of the initial dynamic stress of loess based on the critical influencing properties. The results show that the mean value of particle contact density can reflect the micro-scale contact characteristics of soil,which agrees well with the shear strength of loess. As a link between relationships of dynamic strain and micro-scale parameters,shear strength could be effective to make sure the quantitative estimation method of initial dynamic stress of loess soil. This estimation method of initial dynamic stress could consider the seismic loadings by means of the principle of equivalent cyclic shear stress. To obtain laboratory data of average distance of particle contact density is much easier than testing works to acquire relevant parameters of the shear strength of loess. The calculated results are in good agreement with testing data and perform well on controlling the data error. This means the estimation method has rationality at a certain extent.

关 键 词：黄土 动残余应变 起始动应力 颗粒接触度 抗剪强度 

分 类 号：TU449[建筑科学—岩土工程] TU431[建筑科学—土工工程]