黄河邻岸异形超深基坑支护结构变形研究

STUDY ON THE SUPPORT STRUCTURE DEFORMATION OF SPECIAL-SHAPED ULTRA-DEEP FOUNDATION PIT ADJACENT TO THE BANKS OF THE YELLOW RIVER

根据济南穿黄济洛路隧道合建段深基坑项目,针对黄河邻岸异形深基坑施工支护结构变形开展了研究工作,主要研究成果为:(1)基坑开挖地下连续墙整体变形呈现“中间大、两端小”的形态,变形趋势呈现出先缓后快再趋于平稳的过程;阳角部位变形较大,深度为22 m时的偏移量有增大趋势,ZQL 24偏移值最大为33.1 mm;(2)基坑开挖地下连续墙顶竖向位移在深度为16~22 m时,沉降速度较大,整体为下降的趋势;地下连续墙顶水平位移偏移方向偏向远离基坑一侧,偏移量呈增大趋势,阳角部位的偏移量相对较大;(3)首道支撑处于逐渐受拉状态,其他支撑轴力值基本呈增加趋势,与深层水平位移监测数据吻合,同时混凝土支撑承受荷载远大于钢支撑。

According to Jinan through Huangjiluo road tunnel joint construction section deep foundation pit project,the study was carried out on the support structure deformation in the construction of special-shaped deep foundation pits adjacent to the banks of the Yellow River.Main results are as follows:(1)the overall deformation of the underground continuous wall features the small ends and large middle part during the foundation pit excavation,showing a trend of slow,fast and stable deformation in turn.External corners are deformed greatly,with the offset increasing at a depth of 22m.The maximum offset of ZQL 24 is 33.1mm.(2)The overall vertical displacement of the top of the underground continuous wall decreases due to a high settlement rate at a depth of 16~22m.The horizontal displacement of the top of the underground continuous wall increases,tending to be away from the foundation pit side.External corners have a relatively large offset.(3)The first support is subject to gradual tension,and the axial forces of other supports essentially show an increasing trend,consistent with the monitoring data of deep horizontal displacement.In addition,the load borne by concrete supports is much greater than that by steel supports.