摘要
以吕梁压实黄土为研究对象,通过大量动三轴试验,研究了含水率、干密度、围压和固结应力比等因素对压实黄土动剪切模量和阻尼比的影响。结果表明:压实黄土的动剪切模量随动剪应变的增大而减小,可用半对数坐标系下的直线方程进行拟合;动剪切模量和初始动剪切模量均随含水率的增大而减小,随干密度、围压和固结应力比的增大而增大;固结应力比对动剪切模量的影响随着动剪应变的增大而减弱;阻尼比大致上随着含水率的增大呈缓慢增大趋势,随着干密度、围压和固结应力比的增大呈缓慢减小趋势。进行压实黄土的动力研究,对高烈度黄土地区的大规模基础建设具有重要的理论和现实意义。
The Lvliang compacted loess is selected in this paper as the research object. Through a large number of dynamic triaxial tests,the dynamic shear modulus and damping ratio of compacted loess under the moisture content,dry density,confining pressure and consolidation stress ratio are examined. The results show that the dynamic shear modulus of the compacted loess decreases with the increasing of dynamic shear strain.We can use linear equations under a semi-logarithmic coordinates to fit their relationship. The dynamic shear modulus and initial dynamic shear modulus decrease with the increasing moisture content and increase with the increasing dry density,confining pressure and consolidation stress ratio. The consolidation stress ratio has less effect on the dynamic shear modulus with the increasing dynamic shear strain. Damping ratio generally show a slowly increasing trend with the increasing moisture content,and show a slowly decreasing trend with the increasing dry density,confining pressure and consolidation stress ratio. Dynamic researches on the compacted loess are of important theoretical and practical significance for building large-scale infrastructure in loess areas of high seismic intensity.
引文
[1]Wang Z J,Luo Y S,Guo H,et al.Effects of initial deviatoric stress ratios on dynamic shear modulus and damping ratio of undisturbed loess in China[J].Engineering Geology,2012,143:43-50.
[2]王志杰,骆亚生,王瑞瑞,等.不同地区原状黄土动剪切模量与阻尼比试验研究[J].岩土工程学报,2010,32(9):1464-1469.[WANG Z J,LUO Y S,WANG R R,et al.Experimental study on dynamic shear modulus and damping ratio of undisturbed loess in different regions[J].Chinese Journal of Geotechnical Engineering,2010,32(9):1464-1469.(in Chinese)]
[3]谷天峰,王家鼎,任权,等.循环荷载作用下黄土边坡变形研究[J].岩石力学与工程学报,2009,28(增刊):3156-3162.[GU T F,WANG J D,REN Q,et al.Study on deformation of loess slope under cyclic load[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(Sup):3156-3162.(in Chinese)]
[4]王峻,王强,王杰民.震后黄土动力学特性试验研究[J].水文地质工程地质,2010,37(4):63-67.[WANG J,WANG Q,WANG J M.Experimental study on the dynamic characteristics of postearthquake loess[J].Hydrogeology&Engineering Geology,2010,37(4):63-67.(in Chinese)]
[5]郭乐,王家鼎,谷天峰.宝鸡市渭北台塬马兰黄土震陷特性研究[J].水文地质工程地质,2012,39(2):61-65.[GUO L,WANG J D,GU T F.A study of loess seismic subsidence of tableland to the north Weihe River in Baoji City[J].Hydrogeology&Engineering Geology,2012,39(2):61-65.(in Chinese)]
[6]刘保健,张晓荣,程海涛.应变控制下压实黄土的动三轴试验研究[J].岩土力学,2007,28(6):1073-1076.[LIU B J,ZHANG X R,CHENG H T.Study on compacted loess under strain control at dynamic triaxial test[J].Rock and Soil Mechanics,2007,28(6):1073-1076.(in Chinese)]
[7]杨利国,骆亚生,李焱,等.初始应力条件对压实黄土动强度影响的研究[J].岩土力学,2010,31(1):87-91.[YANG L G,LUO Y S,LI Y,et al.Research on effect of initial stress conditions on dynamic strength of compacted loess[J].Rock and Soil Mechanics,2010,31(1):87-91.(in Chinese)]
[8]杨利国,骆亚生,王志杰.中主应力对压实黄土动变形特性的影响[J].世界地震工程,2010,26(增刊):59-64.[YANG L G,LUO Y S,WANG Z Z.Effect of intermediate principal stress on dynamic deformation of compacted loess[J].World Earthquake Engineering,2010,26(Sup):59-64.(in Chinese)]
[9]杨利国,骆亚生,李焱.主应力轴旋转对压实黄土动变形特性的影响[J].工程地质学报,2010,18(3):392-397.[YANG L G,LUO Y S,LI Y.Effect of principal stress rotation on dynamic deformation of compacted loess[J].Journal of Engineering Geology,2010,18(3):392-397.(in Chinese)]
[10]李又云,谢永利,刘保健.路基压实黄土动力特性的试验研究[J].岩石力学与工程学报,2009,28(5):1037-1046.[LI Y Y,XIE Y L,LIU B J.Experimental research on dynamic characteristics of roadbed compaction loess[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(5):1037-1046.(in Chinese)]
[11]HARDIN B O,DRNEVICH V P.Shear modulus and damping in soils:design equation and curves[J].Journal of Soil Mechanics and Foundation Division,ASCE,1972,98(7):667-692.
[12]谢定义.土动力学[M].西安:西安交通大学出版社,1988.[XIE D Y.Soil dynamics[M].Xi’an:Xi’an Jiaotong University Press,1988.(in Chinese)]