基坑开挖回弹再压缩变形试验研究  

Model test on rebound deformation in foundation pit excavation

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：《岩土工程学报》2010年第S2期81-84,共4页Chinese Journal of Geotechnical Engineering

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

摘　　要：通过室内模型试验对土体回弹变形与再压缩变形规律进行了研究。新的回弹变形观测方法的应用弥补了现有观测方法的不足,取得了较好的效果。在模型试验中,基底以下同一深度处土体的回弹变形沿基坑宽度分布形状类似倒扣的锅底形,基坑中心处土体回弹变形量最大,越靠近基坑边缘其回弹变形越小。基坑工程空间效应对回弹变形有明显影响,且在基底以下一定深度范围内对埋深越大的土体影响也越大。在卸荷量与再加荷量等同的情况下,土体的回弹变形量小于再压缩变形量。Characteristics of rebound and recompression deformation in pit excavation is researched by the method of model test.New measuring method of deformation is adopted to overcome the shortcomings of traditional method.The model test results show that the rebound deformation alone width at a specific depth under pit base shapes like an upturned pot,with maximum value at center and minimum value at edge.Space effect has remarkable influence on the rebound deformation.It's observed that the deeper soil is affected more obviously within a specific depth under pit base.With the same magnitude of unload and reload force,the rebound deformation is less than recompression deformation.

关 键 词：回弹变形 再压缩变形 卸荷比 空间效应 

分 类 号：TU433[建筑科学—岩土工程]