【作者】 吴晓梅；

【导师】 邱长林；

【作者基本信息】 天津大学 ， 岩土工程， 2006， 硕士

【摘要】 建筑物建成后地基土体在主固结沉降完成后总是会伴随着随时间发展的次固结沉降即土骨架的蠕变变形。在深厚软粘土地基上建造建筑物,沉降量和差异沉降量控制是问题的关键。软土地基地区建筑地基工程事故大部分是由沉降量或沉降差过大造成的,特别是不均匀沉降对建筑物的危害最大。深厚软粘土地基建筑物的沉降量与工程投资密切相关。因此,合理控制沉降量非常重要。所以在工程的设计过程中有必要找到一个合理有效且实用的计算和预测建筑物蠕变变形方法,以保证建筑物安全及节省工程投资。本文引入由Vermeer和Neher(1998)提出的软土蠕变模型,详细介绍了一维软土蠕变模型的建立和由一维模型扩展到三维模型的过程,以及模型参数的选择方法。同时采用PLAXIS程序模拟了一维压缩试验过程和一高层建筑地基土的加载蠕变过程,验证了采用软土蠕变模型计算土体蠕变问题的可靠性。将经验证后行之有效计算方案运用到天津港突堤的蠕变计算中,通过理论计算的结果和现场实际观测的结果进行比较,对模型各参数进行灵敏度分析。利用模型的计算结果分析天津港突堤的蠕变特性,并对其未来的蠕变情况和蠕变趋势做出相应的预测。更多还原

【Abstract】 Large primary settlements of dams and embankments are usually followed by creep settlements after they being build. The key point of building structure in deep soft soil foundation is how to control the total settlement and the differential settlement. Most of the foundation construction accidents in the soft soil area are caused by large settlements, especially, the differential settlement can do great harm to the structures. Moreover, the settlements of the foundations have a close relationship with the construction investment. Therefore it is important to control the settlement, and find a reasonable and efficient way to calculate and predict the creep settlement of the foundations.In this paper, a soft-soil-creep model developed by Vermeer & Neher(1998) is introduced. A full description of the formulation of the soft-soil-creep model and the progress how to extend 1D-creep model into 3D-creep model are given. In addition, attention is focused on the model parameters. Finally, a validation of the 3D model is presented by considering both model predictions and data from an oedometer test and a survey report of a high-rise building foundation.The calculation program proved to be effective in practice is applied to the creep calculation of Tianjin Harbor Breakwater. The model and the parameters are revised by analyzing the parameter sensitivity and comparing the theoretical calculation results with the actual measured results. The creep properties of Tianjin Harbor Breakwater are analyzed by the calculation result of the model, and accordingly, some relevant predictions of the future creep tendency and phenomena can be made.更多还原