低震多频高烈度区黄土的动弹性模量和阻尼比特性

发布时间：2018-10-17 17:24

【摘要】：在调查山西地震动历史事件的基础上,对山西汾渭地堑带上高速公路边坡黄土进行了动力特性参数的试验研究。首先,选取典型黄土边坡进行现场爆破试验获取了边坡黄土介质的地震动时程曲线;接着,以这些动力特性作为动三轴试验的模拟加载方式和参数,对不同路段边坡的30组马兰黄土(Q3)和离石黄土(Q2)进行了室内动三轴试验,获得了边坡黄土在低震多频动荷载下动力特性的一些规律:冲击地震荷载作用下加速度幅值比正弦循环波幅值较大;相同的动荷载作用下,动弹性模量(Ed)越大,黄土的动黏聚力(Cd)越高,动摩擦角(φd)则越低,离石黄土(Q2)与马兰黄土(Q3)的初始动弹性模量(Ed0)分别为80~150 kPa、25~100 kPa;动弹性模量均值(Eda)分别为10~20 kPa,10~30 kPa;对二者的动应变(εd)-动阻尼比(λd)曲线拟合得动阻尼比(λd)的增长速率分别为马兰黄土(Q3)0.199 8,离石黄土(Q2)为0.128 5。
[Abstract]:Based on the investigation of historical events of ground motion in Shanxi Province, the dynamic characteristic parameters of loess on highway slope in Fen-Wei graben belt of Shanxi Province are studied experimentally. Firstly, the time-history curve of loess soil motion is obtained by field blasting test of typical loess slope, and then, these dynamic characteristics are used as the simulation loading mode and parameters of dynamic triaxial test. The dynamic triaxial tests of 30 groups of Ma Lan loess (Q3) and Lishi loess (Q2) on different sections of slope were carried out. Some laws of dynamic characteristics of loess slope under low seismic and multi-frequency dynamic loads are obtained: the amplitude of acceleration under impact earthquake is larger than that of sinusoidal cyclic wave, and the dynamic modulus of elasticity (Ed) is larger under the same dynamic load. The higher the dynamic cohesive force (Cd) of loess is, the lower the dynamic friction angle (蠁 d) is. The initial dynamic modulus of elasticity (Ed0) of Lishi loess (Q2) and Ma Lan loess (Q3) were 80 ~ 150 kPa,25~100 kPa;, respectively. The mean value of dynamic modulus of elasticity (Eda) was 10 ~ 20 kPa,10~30 kPa;. The dynamic strain (蔚 _ d) -dynamic damping ratio (位 _ d) curve fitting of Lishi loess (Q _ 2) and Ma Lan loess (Q _ 3) obtained the growth rate of dynamic damping ratio (位 _ d). Ma Lan loess (Q3) 0.199 8, Lishi loess (Q2) 0.128 5.
【作者单位】：太原理工大学地球科学与工程系;山西冶金岩土工程勘察总公司;长安大学地质工程与测绘学院;山西省交通科学研究院岩土工程研究所;
【分类号】：P315.9;U416.14

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