加载路径对重塑黄土一维蠕变特性的影响  

Influence of loading paths on one-dimensional creep characteristics of remodeled loess

作　　者：罗汀[1] 陈栋[1] 姚仰平[1] 刘林[1] 扈胜霞[1] LUO Ting;CHEN Dong;YAO Yang-ping;LIU Lin;HU Sheng-xia(School of Transportation Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学交通科学与工程学院

出　　处：《岩土工程学报》2018年第7期1294-1299,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51579005,11672015);国家重点基础研究发展计划(“973”计划)项目(2014CB047001)

摘　　要：黄土因具有蠕变特性,在荷载σ＇v不变的情况下,蠕变时间t的增长也能引起土体孔隙比的减小,假设蠕变时间的增长也为一种加载,为探求重塑黄土变形量的σ＇v-t加载次序相关性,进行了4种加载路径的试验,试验结果表明：重塑黄土变形量的σ＇v-t加载次序相关性显著,虽然各试样的最终荷载相同,加载过程中的蠕变时间也相同,但是,在一级加载过程中,先蠕变的试样比先施加荷载的试样变形量小,在分级加载过程中,按照＂荷载—蠕变—荷载＂施加次序的试样比＂荷载—荷载—蠕变＂施加次序的试样变形量小,此结论可为工期较长的高填方工程的施工计划安排提供一定参考。姚仰平等提出的一维蠕变公式能较好反映重塑黄土变形量的蠕变时间和荷载的加载次序相关性,公式所需5个参数均能简单获得。The increasing creep time is assumed to be another kind of load, for the loess is of creep characteristics, that is, the increasing creep time t may induce the void ratio to decrease when the load σ＇v is constant. Aiming at exploring the dependency of σ＇v-t loading sequence for the loess deformation, four loading paths are tested. The results indicate that the dependency of σ＇v-t loading sequence for the loess deformation is obvious. All samples arrive at the same stress load in the end, and the creep time is also the same during the loading procedure. However, in the process of one-time stress load, the deformation of the specimen which is crept first is smaller than that of the specimen which is loaded first, and in the process of grading stress load, the deformation of the specimen whose loading sequence is load-creep-load is smaller than that of the specimen whose loading sequence is load-load-creep. This conclusion can offer certain reference for the construction schedule of the long-period high embankment engineering. A one-dimensional creep formula proposed by Yao Yang-ping et al. is able to reflect the dependency of σ＇v-t loading sequence for the loess deformation, and the 5 parameters this formula requires can be obtained easily.

关 键 词：重塑黄土 变形量 蠕变时间 加载次序 相关性 

分 类 号：TU444[建筑科学—岩土工程]