砂流法施工致沉管隧道管段竖向位移的试验研究  

Vertical displacement of tube segment of immersed tunnels caused by sand flow construction

作　　者：黎伟[1,2,3] 房营光[1,2] 莫海鸿[1,2] 谷任国[1,2] 陈俊生[1,2] 袁伟耀 

机构地区：[1]华南理工大学土木与交通学院,广东广州510641 [2]华南理工大学亚热带建筑科学国家重点实验室,广东广州510641 [3]广州电力设计院,广东广州510075 [4]东莞建青建筑设计有限公司,广东东莞523000

出　　处：《岩土工程学报》2013年第6期1102-1108,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51108190);华南理工大学亚热带建筑科学国家重点实验室自主研究课题资助项目(2012ZC27);广州市资助项目(GTCC2008-253)

摘　　要：利用足尺砂流法模型试验模拟了砂流法处理沉管隧道地基施工致使管节竖向位移的全过程,获得了管节模型的相对高程-时程曲线、竖向位移量及砂盘的形态特征。结果表明:模型在试验中先后经历了砂盘正常扩展、缓慢跳动位移、快速平稳位移3个阶段;模型在缓慢跳动位移过程中的位移量、位移速率均较快速平稳位移过程中的要小。模型板的竖向位移使得流缝区域缩小,流槽厚度变薄且密集分布于砂盘顶面(占砂盘顶面积的30%以上);砂颗粒压积于砂盘顶部形成水平薄层状结构,是模型板竖向位移的直接原因;模型板竖向位移过程明显影响砂盘的半径扩展。工程实践中可适当利用管节的缓慢跳动位移过程减小流缝、流槽厚度,但需采取措施保证砂盘半径在管节产生竖向位移前达到设计值。By using the full-scale model tests on the sand-flow method, the whole process of vertical displacement of tube segment in the construction of immersed tunnel foundation treated by sand-flow method is simulated. The relative elevation versus time-history curves of the tube segment model, the amount of vertical displacement and the morphological characteristics of the sand deposit are obtained. The test results show that the model tests have three processes, that is, normal expansion of sand deposit, slow-beating displacement and fast-smooth displacement. The displacement amount and displacement rate of model in the slow-beating displacement process are smaller than those in the fast-smooth displacement process. The vertical displacement makes the gap area small and the chutes thin and densely distributed on the top surface of the sand deposit. Sand particles cumulate on the sand-deposit top and form horizontal layers, which causes the vertical displacement directly. The displacement process significantly affects the expansion of the sand deposit. The process of the slow-beating displacement can be used to reduce the thickness of the gap and chutes in engineering practice, but measures should be taken to ensure that the sand deposit radius meet the design requirements before the vertical displacement.

关 键 词：沉管隧道 地基处理 砂流法 足尺模型试验 管段竖向位移 

分 类 号：U455[建筑科学—桥梁与隧道工程]