饱和场地土动力特性试验研究
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摘要
在工程实际中认为饱和度超过80%即为饱和土,但在室内土工试验中制作的土样饱和度达95%以上,后者经过试验测定,动力参数与前者实际上有一定差异。在50,100,200 kPa三种固结压力下分别对饱和度为95%,92%,88%,83%的饱和土样进行了循环单剪试验,得到了4种土样在3种固结压力下的最大动剪模量Gdmax和最大阻尼比Dmax,以及动剪模量比G/Gdmax-γ和阻尼比D/Dmax-γ归一化数值,并进行了对比分析。结果表明:在同一固结压力下,土样的Gdmax,Dmax,G/Gdmax随着饱和度增大有相对递减的趋势,而阻尼比D/Dmax数值随着饱和度加大而逐渐增加;随着固结压力的增大,4种土样的Gdmax,Dmax以及G/Gdmax-γ(γ为动剪应变)数值上差异逐渐减小。最后对此种现象进行了讨论并分析其产生的原因。
In project it is thought that the soil with saturation over 80% is called saturated soil.But the saturation of the sample produced in the indoor experiment reached over 95 %.In fact the dynamic parameter of the latter attained through the test is different from that of the former.In this paper,the cyclic simple shear tests of the saturated soil of saturation 95 %,92 %,88 % and 83 % were carried out under the consolidation pressure of 50 kPa,100 kPa and 200 kPa respectively.Of four different sorts of soil sample under three different consolidation pressures,the maximum dynamic shear modulus Gdmax,the maximum damping ratio Dmax and the dynamic modulus ratio G/Gdmax-γ,the damping ratio D/Dmax-γ generalized curve were attained and analyzed comparatively.The results show that under the same consolidation pressure,the value of the Gdmax,Dmax,G/Gdmax shrink according to the growth of saturation;but the damping ratio D/Dmax,quite on the contrary,becomes larger with the raise of saturation,with the increasing of the consolidation pressure,the differences among the Gdmax,Dmax and G/Gdmax-γ decrease gradually.Finally,this kind of phenomenon and its causes are discussed and analyzed.
In project it is thought that the soil with saturation over 80% is called saturated soil.But the saturation of the sample produced in the indoor experiment reached over 95 %.In fact the dynamic parameter of the latter attained through the test is different from that of the former.In this paper,the cyclic simple shear tests of the saturated soil of saturation 95 %,92 %,88 % and 83 % were carried out under the consolidation pressure of 50 kPa,100 kPa and 200 kPa respectively.Of four different sorts of soil sample under three different consolidation pressures,the maximum dynamic shear modulus Gdmax,the maximum damping ratio Dmax and the dynamic modulus ratio G/Gdmax-γ,the damping ratio D/Dmax-γ generalized curve were attained and analyzed comparatively.The results show that under the same consolidation pressure,the value of the Gdmax,Dmax,G/Gdmax shrink according to the growth of saturation;but the damping ratio D/Dmax,quite on the contrary,becomes larger with the raise of saturation,with the increasing of the consolidation pressure,the differences among the Gdmax,Dmax and G/Gdmax-γ decrease gradually.Finally,this kind of phenomenon and its causes are discussed and analyzed.
引文
[1]孙静,袁晓铭,孙锐.土动剪切模量和阻尼比的推荐值和规范值的合理性比较[J].地震工程与工程振动,2004,24(2):125-133.SUN Jing,YUAN Xiao-ming,SUN Rui.Reasonability comparison between recommended and code values of dynamic shear modulus and damping ratio of soils[J].Earthquake Engineering and Engineering Vibration,2004,24(2):125-133.
[2]王海东,尚守平,卢华喜,等.场地土动剪模量的试验对比研究[J].湖南大学学报(自然科学版),2005,32(3):33-37.WANG Hai-dong,SHANG Shou-ping,LU Hua-xi,et al.Comparative study of dynamic shear modulus through laboratory experiments[J].Journal of Hunan University(Natural Sciences),2005,32(3):33-37.
[3]HADHIAN A H,TSENG W S,XIE J F.The learning from the large scale Lotung soil-structure interaction experiments[J].World Earthquake Engineering,1993,(4):49-59.
[4]YANG J,SATO T,SAVIDIS S,et al.Horizontal and vertical components of earthquake ground motion at liquefiable sites[J].Soil Dynamics and Earthquake Engineering,2002,(22):229-240.
[5]姬美秀,陈云敏.不排水循环荷载作用过程中累积孔压对细砂弹性剪切模量Gmax的影响[J].岩土力学,2005,26(6):884-888.JI Mei-xiu,CHEN Yun-min.Effect of accumulated pore pressure on shear modulus Gmax of saturated fine sand during undrained cyclic loading[J].Rock and Soil Mechanics,2005,26(6):884-888.
[6]TOWHATA I,ISHIHARA K.Undrained strength of sand undergoing cyclic rotation of principal stress axes[J].Soils and Foundations,JSSMFE,1985,25(2):135-147.
[7]南京水利科学研究院土工研究所.土工试验技术手册[M].北京:人民交通出版社,2003.
[8]BORDEN R H,SHAO L,GUPTA A.Dynamic properties of piedmont residual soils[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,1996,122(10):813-821.
[9]任慧.场地动力反应的理论分析与场地土动力特性试验研究[硕士学位论文D].长沙:湖南大学,2004.
[10]吴世明.土动力学[M].北京:中国建筑工业出版社,2000.
[11]谢定义.土动力学[M].西安:西安交通大学出版社,1988.
[2]王海东,尚守平,卢华喜,等.场地土动剪模量的试验对比研究[J].湖南大学学报(自然科学版),2005,32(3):33-37.WANG Hai-dong,SHANG Shou-ping,LU Hua-xi,et al.Comparative study of dynamic shear modulus through laboratory experiments[J].Journal of Hunan University(Natural Sciences),2005,32(3):33-37.
[3]HADHIAN A H,TSENG W S,XIE J F.The learning from the large scale Lotung soil-structure interaction experiments[J].World Earthquake Engineering,1993,(4):49-59.
[4]YANG J,SATO T,SAVIDIS S,et al.Horizontal and vertical components of earthquake ground motion at liquefiable sites[J].Soil Dynamics and Earthquake Engineering,2002,(22):229-240.
[5]姬美秀,陈云敏.不排水循环荷载作用过程中累积孔压对细砂弹性剪切模量Gmax的影响[J].岩土力学,2005,26(6):884-888.JI Mei-xiu,CHEN Yun-min.Effect of accumulated pore pressure on shear modulus Gmax of saturated fine sand during undrained cyclic loading[J].Rock and Soil Mechanics,2005,26(6):884-888.
[6]TOWHATA I,ISHIHARA K.Undrained strength of sand undergoing cyclic rotation of principal stress axes[J].Soils and Foundations,JSSMFE,1985,25(2):135-147.
[7]南京水利科学研究院土工研究所.土工试验技术手册[M].北京:人民交通出版社,2003.
[8]BORDEN R H,SHAO L,GUPTA A.Dynamic properties of piedmont residual soils[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,1996,122(10):813-821.
[9]任慧.场地动力反应的理论分析与场地土动力特性试验研究[硕士学位论文D].长沙:湖南大学,2004.
[10]吴世明.土动力学[M].北京:中国建筑工业出版社,2000.
[11]谢定义.土动力学[M].西安:西安交通大学出版社,1988.
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