岷江上游欢喜坡冰水堆积体原位大剪试验研究  

Research on In-situ Large-scale Shear Test on Huanxipo Glacial Accumulation Body of the Minjiang River Valley

作　　者：王琦[1] 冯文凯[1] 黄家华[1] 艾国海 白慧林[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059

出　　处：《科学技术与工程》2016年第8期254-260,共7页Science Technology and Engineering

摘　　要：岷江中上游河谷两岸广泛分布着第四纪冰水堆积体,其特征在我国西南地区大江大河的河谷地带具有很强的代表性。正是由于此类冰水堆积体具有复杂的结构特征与特殊的形成演化过程,造就了其力学强度特征与其他堆积体相比存在较大的差异。以欢喜坡冰水堆积体为研究对象,采用大剪仪对在不同土石性质不同含水率下的冰水堆积体进行现场大剪试验。试验结果表明:该冰水堆积体应力应变曲线具有明显的弹性变形和塑性变形阶段,没有明显的应力屈服特征。土石性质与含水率是影响冰水堆积体强度特性的重要因素。天然状态下,冰水堆积物的应力应变关系呈现出一定的应变硬化特征。当含水率增大时,应力应变关系出现弱应变硬化特征。孔隙比小、密实度高、含石量高的冰水堆积物强度也显著提高。通过邓肯张双曲线模型对欢喜坡冰水堆积体大剪试验获得的应力应变曲线进行拟合,拟合效果良好。The Minjiang River Valley has a strong representation of the Quaternary glacial accumulation body,which is widely distributed in the region valley of southwest China. It is precisely because of this kind of glacial accumulation body peculiar special formation and evolution process and the structural features of the complicated and the larger difference between the other deposits,The strength characteristics are greatly different from other accumulation bodies. In-situ large-scale shear test is used to investigate the strength characteristics of the glacial accumulation body under different soil-rock characteristics and moisture contents in Huanxipo glacial accumulation body. The results show that the stress-strain curve of the glacial accumulation body has obvious elastic deformation and plastic deformation stage,and no obvious stress yield characteristics; the soil-rock characteristics and moisture contents are important factors that affect the strength of glacial accumulation body,The stress-strain relationship of the glacial accumulation body presents some characteristic of strain hardening in the natural state,it presents the characteristic of weak strain hardening when the moisture content increases,while the strength of the glacial accumulation body that has the characteristic of slow void ratio,high compaction degree and high rock-soil ratio increases significantly.The relationship between stress-strain of In-situ large-scale shear test on Huanxipo glacial accumulation body can be simulated well by using Duncan-Chang hyperbolic model.

关 键 词：冰水堆积体 现场大剪试验 强度特性 双曲线模型 欢喜坡 

分 类 号：TU413.1[建筑科学—岩土工程]