深大基坑处理技术在城市建设中的应用

发布时间：2018-07-11 13:58

本文选题：深大基坑 + 止水帷幕　；参考：《石家庄铁道大学》2015年硕士论文

【摘要】：以中国国际贸易中心三期B阶段基坑工程为背景,针对深大基坑处理技术面临的相邻建筑物距离近、开挖深度大、建设施工环境恶劣、场区水文地质条件差、开挖受土体失稳变形、渗流共同作用的复杂问题,深入分析了深大基坑处理技术在城市建设中的应用。通过深大基坑围护结构分析模型的建立,得出不同开挖深度基坑的围护结构变形、土压力计算结果,为选择合适的基坑边坡支护形式提供依据。采用极限平衡法对基坑及支护结构进行稳定性研究,计算其稳定系数,通过使用变位分析对支护结构的变形和内力进行计算,对设计参数进行研究,并根据研究结果对设计进行调整和优化。针对现场实际的基坑渗流问题对基坑影响的研究,采用“止水帷幕+基坑内降水”、“超高压桩间旋喷水泥浆+护坡桩”和在基坑外侧对变形比较敏感的区域设置观测井的处理方式,实现全封闭止水帷幕切断坑内外水力联系、实现基坑内潜水与第一层承压水的有效降排和水位的定期观测。在原有建筑护坡桩上进行钢筋应力监测、锚杆拉力监测、护坡桩斜侧观测、护坡桩定位移观测、地下水位变化观测,设立预警系统,确保止水帷幕完整和临近建筑物的安全。
[Abstract]:Based on the third stage B foundation pit project of the China International Trade Center, the adjacent buildings are close, the excavation depth is large, the construction environment is bad, and the hydrogeological conditions in the field area are poor, which is faced by the treatment technology of deep and large foundation pit. The application of deep and large foundation pit treatment technology in urban construction is deeply analyzed. Through the establishment of the analysis model of the retaining structure of deep and large foundation pit, the deformation of the retaining structure and the calculation result of earth pressure of the foundation pit with different excavation depth are obtained, which provides the basis for selecting the appropriate supporting form of the slope of the foundation pit. The stability of foundation pit and supporting structure is studied by limit equilibrium method, and the stability coefficient is calculated. The deformation and internal force of supporting structure are calculated by displacement analysis, and the design parameters are studied. According to the research results, the design is adjusted and optimized. In view of the study on the influence of the seepage problem on the foundation pit, the "dewatering in the pit of the waterproof curtain" is adopted. "Super-high pressure pile with rotary grouting cement slurry for slope protection" and the treatment method of setting observation wells in the areas outside the foundation pit that are sensitive to deformation can realize the complete sealing curtain to cut off the hydraulic connection inside and outside the pit. The submersible in foundation pit and the effective discharge of the first confined water and the regular observation of the water level are realized. The reinforcement stress monitoring, anchor tension monitoring, slope protection pile slope observation, slope protection pile location and displacement observation, groundwater level change observation, setting up early warning system are carried out on the original building slope protection pile to ensure the integrity of the waterproof curtain and the safety of the adjacent buildings.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753

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