复杂地质条件下深基坑的变形分析与预测

发布时间：2018-01-15 08:36

本文关键词：复杂地质条件下深基坑的变形分析与预测　出处：《河北大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着经济和社会的发展,城市建设用地越来越紧张,过去认为不适合建设的土地不得不利用,同时随着技术的进步,楼房建设的越来越高,相对应的基坑也越来越深,并且基坑周边环境趋于复杂,由基坑开挖引起的重特大事故时有发生,造成了巨大的经济损失,因此对深基坑进行监测,做到信息化施工和管理显得尤为重要。以处于岩溶和采空双重不良地质条件下的唐山某深基坑工程为背景,分析不同支护形式对深基坑变形的影响以及深基坑开挖阶段与开挖完成至回填阶段变形量之间的关系,并采用灰色模型对基坑变形进行预测,探究维数、时间间隔与预测精度之间的关系,并得出以下结论:(1)开挖阶段,两种不同支护形式下的基坑坡顶水平位移差异较大,锚杆支护的坡顶水平位移大于排桩+锚杆支护的坡顶水平位移,而对基坑坡顶竖向位移影响很小。(2)开挖阶段水平位移约占总变形量的68%~78%,坡顶竖向位移约占总变形量的61%~67%。(3)开挖阶段,在坡顶水平位移的预测中,5维为最优维数,最优时间间隔为5天。(4)开挖完成至回填阶段,在坡顶水平位移的预测中,维数与间隔天数对预测结果的精度并无影响。
[Abstract]:With the development of economy and society, the urban construction land is more and more tense. The land that was considered unsuitable for construction has to be used in the past. At the same time, with the progress of technology, the building construction is getting higher and higher. The corresponding foundation pit is becoming deeper and deeper, and the surrounding environment of the foundation pit tends to be complex. The serious and serious accidents caused by the excavation of the foundation pit occur frequently, resulting in huge economic losses, so the monitoring of the deep foundation pit is carried out. Information construction and management is particularly important, with the background of a deep foundation pit project in Tangshan, which is under the double unfavorable geological conditions of karst and mining. This paper analyzes the influence of different supporting forms on the deformation of deep foundation pit and the relationship between the deformation of deep foundation pit and the period from excavation to backfill. The grey model is used to predict the deformation of foundation pit and explore the dimension. The relationship between time interval and prediction accuracy, and draw the following conclusion: 1) in the excavation stage, the horizontal displacement of the slope top of the foundation pit under two different support forms is quite different. The horizontal displacement of the roof of bolting is greater than that of the bolting with row piles, but the vertical displacement of the roof of foundation pit has little effect on the vertical displacement.) the horizontal displacement in excavation stage accounts for 68% or 78% of the total deformation. The vertical displacement of the top of the slope accounts for about 61% of the total deformation at the excavation stage. In the prediction of the horizontal displacement at the top of the slope, the optimal dimension is 5 dimensions. The optimal interval is 5 days. 4) the excavation is completed to the backfill stage. In the prediction of the horizontal displacement of the slope, the dimension and the interval days have no effect on the accuracy of the prediction results.
【学位授予单位】：河北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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