摘要
以典型工程为依托,借助有限元软件,开展基坑施工过程模拟,对基坑开挖过程支护结构与周边环境进行响应评价,以此为基础优化基坑支护方案,并通过现场实测验证。研究表明:采用原有支护方案基坑开挖对既有地铁结构产生明显的影响,存在安全隐患,有必要进行优化;基于计算结果作支护方案调整后,车站与隧道最大位移较原有方案减小29%和27%;紧邻地铁侧采用灌注桩围护引起的位移小于连续墙,究其原因是连续墙成槽影响产生可观的变形;同时采用灌注桩围护能显著降低工程造价,实际工程设计施工应引起重视。与实测结果对比表明,实例基坑采用的计算模型具备合理性。
Based on typical engineering examples, the foundation pit excavation process is simulated with finite element software to evaluate the construction supporting and the impact on surrounding environment. On this basis, the foundation pit supporting is optimized and verified. The results show that the influence of foundation excavation on existing subway structures is significant, which may cause hidden danger. The displacements of station and tunnel decrease respectively by 29% and 27% after supporting optimization based on calculation results. The subway displacement caused by foundation excavation where retaining structures adopts bored pile on the subway side is smaller than that of the diaphragm wall on account of the remarkable deformation caused by the form slot of the diaphragm. Meanwhile, the bored pile can significantly reduce the construction cost, which should be fully considered during design and construction. The comparison with the measured results indicates that the calculation model is reasonable.
出处
《铁道标准设计》
北大核心
2016年第7期125-129,共5页
Railway Standard Design
基金
国家自然科学基金资助项目(51508119)
关键词
深基坑
既有结构
响应评价
方案优化
数值模拟
Deep foundation pit
Existing structure
Response evaluation
Scheme optimization
Numerical simulation
