【作者】 赫全胜；

【导师】 毕继红； 田万义；

【作者基本信息】 天津大学 ， 建筑与土木工程， 2009， 硕士

【摘要】 近年来我国的经济建设和城市建筑发展迅速,人们的生活水平也不断提高,各类建筑与市政工程得到了飞速发展,高层建筑不断增加,深基坑工程愈来愈多。在城市深基坑施工过程中,基坑开挖需要考虑对周边建筑物的影响,位移和应力检测就显得特别重要。本文以北京铁科院工程为背景,运用FLAC有限差分法建立模型对其进行施工阶段的模拟分析,对沉降和位移进行观察,通过和监测数据的对比,提出改进建议。首先,本文论述了深基坑工程的发展状况,深基坑支护常见的问题和未来的发展趋势。对基坑支护结构设计计算理论进行了总结,目前常用的解析法是极限平衡法和弹性抗力法,随着计算机的应用,有限元分析也越来越普遍。其次,以铁科院深基坑工程为背景,对其进行了实际开挖和支护施工过程模拟,对基坑围护结构的水平位移、竖向沉降变形等作了分析研究。模拟结果显示基坑的最大竖向沉降值为10mm,围护结构最大水平位移为20mm。最后,对实际监测数据进行对比分析,监测数据显示地表竖向沉降最大值为24mm,围护结构水平位移最大值为19mm。基坑变形模拟值与监测值存在一定的差异,原因是由于实际工程中受到的施工扰动较大,地下水、施工季节、气候,荷载分布等因素对工程施工影响较大,而模拟时对模型进行了不同程度的简化,计算参数的选取也对模拟结果有一定的影响。更多还原

【Abstract】 These years, with the flourishing development of China’s economy, and urban construction and people’s standard of living, various buildings and municipal projects have developed rapidly, deep excavation engineering comes more and more. We need to consider the effects on the buildings around when deep foundation pits being constructed, displacement and stress tests becomes particularly important. This paper is based on the Beijing china academy of railway sciences , using software FLAC to establish model of the construction phase simulation analysis, then observe the settlement and displacement, compare with monitoring data, make recommendations for improvement.Firstly, the paper discussed the development of deep excavation works, common problems of supporting and the future development trend. Then it summarized the design theories of deep foundation pits. The most commonly used analytical method are limit equilibrium method and elastic resistance. With the application of computer, finite element analysis has become increasingly popular.Secondly, the paper simulated the actual excavation and the step-by-step support of the construction process, analysed the horizontal displacement of support structure and the ground surface sedimentation. Simulation result showed that the greatest vertical pit settlement is 10mm, the maximum of the support structure horizontal distortion is 20 mm.Finally, the paper analysed the actual monitoring data. The data showed that the maximum monitoring vertical surface subsidence is 24mm, the maximum horizontal displacement is19mm. There were some differences between the monitoring data and simulation data, it was because the actual project was affected by the construction disturbance and also the environment、groundwater、the construction season、climate、load distribution and other factors, when the simulation model had varying degrees of simplification, and the selection of parameters in simulation also have an effect on the results.更多还原