低震多频高烈度区黄土的动弹性模量和阻尼比特性  

Study on Dynamic Modulus and Damping Ratio of Loess of Low-magnitude Multi-frequency High-intensity Seismic Regions

作　　者：闫治利 龙建辉[1] 经明[3] 刘海松[3] 籍延青[4] 

机构地区：[1]太原理工大学地球科学与工程系,山西太原030024 [2]山西冶金岩土工程勘察总公司,山西太原030002 [3]长安大学地质工程与测绘学院,陕西西安710054 [4]山西省交通科学研究院岩土工程研究所,山西太原030016

出　　处：《公路交通科技》2014年第6期47-52,126,共7页Journal of Highway and Transportation Research and Development

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（瓯）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—150kPa、25～100kPa；动弹性模量均值（Eda）分别为10—20kPa，10～30kPa；对二者的动应变（sd）一动阻尼比（λd）曲线拟合得动阻尼比（Ad）的增长速率分别为马兰黄土（Q3）0．1998，离石黄土（Q2）为0．1285。Based on the investigation of Shanxi earthquake history events, we conducted experimental research on the dynamic character parameters of expressway slope loess located in the Shanxi Fenwei graben belt. First, we selected typical loess slope to carry out field burst test, and obtained the seismic time history curve of slope loess medium. Then, we used these dynamic characteristics as the loading modes and parameters for dynamic triaxial test, and conducted 30 groups of dynamic triaxial test for Malan loess Q3 and Lishi loess Q2 of different sections, and obtained some regularities of dynamic parameters of slope loess under low-magnitude multi-frequency dynamic load： （1） the acceleration amplitude under impact seismic load is greater than that under sinusoidal cyclic waves; （2） under the same dynamic loads, the greater the dynamic elastic modulus E,, the higher the dynamic cohesion Cd and the lower the dynamic friction angle φd ; （3） the initial dynamic elastic moduli Ed0 of Lishi loess Q2 and Malan loess Q3 are 80 - 150 kPa and 25 - 100 kPa respectively; （4） the mean values of dynamic elastic moduli Ea, of Lishi loess Q2 and Malan loess Q3 are10 -20 kPa and 10 -30 kPa respectively; （5） by fitting the εd - λd, curves of Lishi loess Q2 and Malan loess Q3, we found that the growth rates of dynamic damping ratio Ad of Malan loess Q3 and Lishi loess Q2 are 0. 199 8 and 0. 128 5 respectively.

关 键 词：道路工程 动弹性模量 动三轴试验 边坡黄土 阻尼比 

分 类 号：U417.1[交通运输工程—道路与铁道工程]