交通荷载作用下厚层老黏土动力特性研究  

Dynamic Characteristics of Deep Old Cohesive Soil under the Influence of Traffic Load

作　　者：张树轩 陈立伟 杨为民[2] 司海宝[3] Zhang Shuxuan;Chen Liwei;Yang Weimin;Si Haibao(China Nuclear Power Engineering Co.,Ltd.,Beijing 100840,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Anhui University of Technology,Maanshan 243000,Anhui,China)

机构地区：[1]中国核电工程有限公司,北京100840 [2]中国地质科学院地质力学研究所,北京100081 [3]安徽工业大学,安徽马鞍山243000

出　　处：《岩土工程技术》2020年第5期296-302,F0003,共8页Geotechnical Engineering Technique

摘　　要：京张高铁经过官厅地区时,长期交通循环动荷载作用下可能使厚层老黏土产生变形,从而对高铁安全运行造成影响。针对该问题,利用GDS动态三轴仪,考虑动频率、动应力幅值及固结应力等因素,对官厅厚层老黏土开展土动力特性试验。试验结果表明:官厅地区厚层老黏土强度比一般淤泥质土高;相同固结应力下土体所受动应力比越高,动应变发展越大;同一层土在相同动应力比加载条件下,低频荷载较高频对动应变影响更明显;相同动应力比、相同频率、不同固结应力作用下动应变发展曲线分为破坏型、临界型与稳定型;固结应力大的土体更不易产生动应变,应变达到稳定速率越快。研究成果对交通循环荷载作用下老黏土动力学特性的研究具有参考价值,为高铁沉降控制提供依据。When Beijing-Zhangjiakou high-speed railway pass through the Guanting area,under the long-term traffic cyclic dynamic loading,the deep old cohesive soil will be deformed,which may affect the safety of high-speed railway operation.Focusing on this problem,GDS dynamic triaxial apparatus was used to study the dynamic characteristics of Guanting deep old cohesive soil,considering dynamic frequency,dynamic stress amplitude and consolidation stress.The results show that the strength of Guanting deep old cohesive soil is higher than that of ordinary mucky soil.For the same consolidation stress,the higher the dynamic stress ratio is,the greater development the dynamic strain is.The effect of low frequency load on dynamic strain is more obvious than the high frequency for the same layer.Under the same dynamic stress ratio,same frequency and different consolidation stress,the dynamic strain curves are divided into failure type,critical type and stable type.Soil with higher consolidation stress is more difficult to produce dynamic strain,and the less vibration required to reach stability.The research conclusions have reference value for the study of dynamic characteristics of deep old cohesive soil under traffic cyclic loading,and provide a reference for the settlement control of high-speed railway.

关 键 词：交通荷载 老黏土 加载频率 动应力 固结应力 

分 类 号：TU411.8[建筑科学—岩土工程]