从不同土的室内压缩回弹试验分析基坑开挖回弹变形的特征  

Reaching for the Character of Rebound Deformation of Foundation Pit Excavation by Compression and Resilience Test of Different Sorts of Soil

作　　者：李建民[1] 滕延京[1] 

机构地区：[1]中国建筑科学研究院地基基础研究所,北京100013

出　　处：《建筑科学》2011年第1期72-77,共6页Building Science

基　　金：科技部科研院所专项课题基金项目(编号20070106110630009)

摘　　要：采用卸荷比—回弹模量分析法对砂土、粘性土、淤泥及淤泥质土的回弹变形研究发现,不同性质的土卸荷影响深度亦不同:砂土的卸荷影响深度要小于粘性土的卸荷影响深度,而黏性土的卸荷影响深度又比淤泥及淤泥质土卸荷影响深度小;则在相同开挖条件下,在工程中计算回弹变形量时考虑基底以下土性的不同而引起的计算深度上的差异是更为准确;在相同固结压力下,淤泥及淤泥质土土样的最终回弹量大于同条件下粘性土最终回弹量,砂土的最终回弹量最小。回弹变形随时间的发展与固结压力、卸荷比、土的性质密切相关,同时土性的不同在回弹变形随时间的发展上又存在明显的差异。The method of unloading ratio—resilient modulus is applied to analyze the rebound deformation of sandy soil and cohesive soil and mucky soil,the influence depth of unloading is different in different soils,the influence depth of the unloading in the sandy soil is less than the influence depth in the cohesive soil,and the influence depth of the unloading in the cohesive soil is less than the influence depth in the mucky soil.In the same depth of excavation,the difference of the influence depth in different sorts of soil needs to be considerate when computing the rebound deformation;in the same consolidation pressure,the final rebound deformation of the mucky soil is maximum,and the final rebound deformation of the sandy soil is minimum.The developing of the rebound deformation in time is relevant to many factors such as consolidated stress,unloading ratio and the characters of soil,and for different sorts of soil,the developing law of the rebound deformation in time has obvious distinction.

关 键 词：卸荷比 回弹模量 卸荷影响深度 

分 类 号：TU411[建筑科学—岩土工程] TU411.3[建筑科学—土工工程]