动扭剪荷载条件下黄土动强度特性试验研究
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摘要
在各地区地震频繁发生,黄土地基安全问题严重威胁各项工程建设的情况下,本文利用动扭剪仪,通过对不同地区(兰州、洛川、杨凌、巩义)黄土的动强度特性的研究表明:各地区黄土动强度特性大小顺序分别为杨凌黄土>巩义黄土>洛川黄土>兰州黄土,地理空间分布上有一定规律,即从西北向东南方向增强;试验所用的四种黄土的试验曲线介于拉德-邓肯破坏条件和屈瑞斯卡提出的破坏条件之间,其动强度值均大于邢义川、松岗元、摩尔-库仑破坏条件所对应的强度函数曲线;黄土的黏聚力Cd和内摩擦角φd均随振次的增大都呈减小趋势,其中黏聚力Cd的急剧降低是黄土扭剪破坏的主要原因。
Engineering construction is increasingly threatened by loess ground when earthquake happens more frequently.In this paper,the behaviors of dynamic strength of the loess in different regions(Lanzhou,Luochuan,Gongyi,Yangling) are studied with the dynamic torsional shear tests and the research findings show that: The dynamic strength characteristics of the loess in different regions are Yangling,Gongyi,Luochuan,Lanzhou,the main trend tends to rise from the northwest to the southeast.The dynamic strength point is located in the place between the Lade-Duncan curve and the Tresca curve.Xing Yichuan,Matsuoka-Nakai and Mohr-Coulomb failure conditions are less than the curve of experimental values;the dynamic strength indexes cohesion Cd and friction angle φd all decline as the cycle time increases,but the friction angle changes less than the cohesive strength.
Engineering construction is increasingly threatened by loess ground when earthquake happens more frequently.In this paper,the behaviors of dynamic strength of the loess in different regions(Lanzhou,Luochuan,Gongyi,Yangling) are studied with the dynamic torsional shear tests and the research findings show that: The dynamic strength characteristics of the loess in different regions are Yangling,Gongyi,Luochuan,Lanzhou,the main trend tends to rise from the northwest to the southeast.The dynamic strength point is located in the place between the Lade-Duncan curve and the Tresca curve.Xing Yichuan,Matsuoka-Nakai and Mohr-Coulomb failure conditions are less than the curve of experimental values;the dynamic strength indexes cohesion Cd and friction angle φd all decline as the cycle time increases,but the friction angle changes less than the cohesive strength.
引文
[1]王杰贤.动力地基与基础[M].北京:科学出版社,2001.
[2]骆亚生,田堪良.非饱和黄土的动剪模量与阻尼比[J].水利学报,2005,36(7):830-834.
[3]王兰民,张振中,王峻,等.随机地震荷载作用下黄土动强度的试验方法[J].西北地震学报,1991,13(3):50-55.
[4]郭鸿,骆亚生,李广冬.考虑地区差异性的饱和黄土三轴渗透试验研究[J].中国农村水利水电,2009,(10):112-114.
[5]王兰民,袁中夏,王峻,等.强夯处理后黄土地基的动力特性与地震性能[J].岩石力学与工程学报,2003,22(增2):2 840-2847.
[6]田堪良,张慧莉,张伯平,等.动扭剪荷载作用下非饱和黄土动力特性试验研究[J].岩石力学与工程学报,2004,23(24):4 151-4155.
[7]谢定义.土动力学[M].西安:西安交通大学出版社,1988.
[8]邢义川,骆亚生,李振.黄土的断裂破坏强度[J].水力发电学报,1999,67(4):36-44.
[2]骆亚生,田堪良.非饱和黄土的动剪模量与阻尼比[J].水利学报,2005,36(7):830-834.
[3]王兰民,张振中,王峻,等.随机地震荷载作用下黄土动强度的试验方法[J].西北地震学报,1991,13(3):50-55.
[4]郭鸿,骆亚生,李广冬.考虑地区差异性的饱和黄土三轴渗透试验研究[J].中国农村水利水电,2009,(10):112-114.
[5]王兰民,袁中夏,王峻,等.强夯处理后黄土地基的动力特性与地震性能[J].岩石力学与工程学报,2003,22(增2):2 840-2847.
[6]田堪良,张慧莉,张伯平,等.动扭剪荷载作用下非饱和黄土动力特性试验研究[J].岩石力学与工程学报,2004,23(24):4 151-4155.
[7]谢定义.土动力学[M].西安:西安交通大学出版社,1988.
[8]邢义川,骆亚生,李振.黄土的断裂破坏强度[J].水力发电学报,1999,67(4):36-44.
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