山区公路CFG桩复合地基沉降预测方法研究及其应用

发布时间：2018-05-17 06:05

本文选题：复合地基 + 沉降预测　；参考：《重庆交通大学》2014年硕士论文

【摘要】：山区软土地基不仅具有承载力低、沉降量大、固结时间长等不利的工程特性，而且还具有复杂、隐蔽、不均匀等独有的不利特性，其潜在的工后沉降易对道路结构及交通运营安全造成危害。因此不仅需要对软基进行合理的处理，也需要对处理后的地基进行准确的沉降预测，利用相关工程资料，选取合理的沉降预测方法及模型预测地基沉降对控制施工进度、安排施工组织、确定分层填筑高度、间歇时间以及预压时间提供一定的指导，具有一定理论价值和工程意义。论文以贵州省交通运输厅科技项目《贵州山区高速公路软基处理关键技术研究与示范工程》为依托，，结合了杭瑞高速贵州段遵毕高速公路第十八合同段内的软土地基处理方法，对山区公路CFG桩复合地基沉降预测的方法进行研究。本文主要完成了以下几个方面的研究工作： ①将CFG桩复合地基运用到山区软基处理中，对复合地基承载力计算、沉降变形理论及沉降量计算方法进行了阐述，并对示范工程CFG桩复合地基进行了设计计算。 ②介绍了目前常用的基于实测数据的预测方法，并着重研究了该类方法中的曲线拟合法、灰色系统模型及神经网络的原理、计算过程及适用范围。选取了三种具有代表性的方法：泊松曲线法、GM（1,1）及BP神经网络法，在其原理指导下，利用MATLAB软件编制了沉降预测系统，实现了预测方法系统的集成与应用，并以依托工程的实测沉降数据为例，运用于沉降数据预测系统。 ③利用Plaxis有限元分析软件对CFG桩复合地基沉降进行数值模拟分析，将沉降预测系统计算结果与实测沉降数据进行对比分析。 ④在室内进行了CFG桩复合地基的土工离心试验，观测整个路基模型的变形与沉降；同时，将土工离心试验结果与预测系统中各方法的预测结果和有限元的数值模拟结果进行对比，进一步对CFG桩复合地基沉降进行分析研究。
[Abstract]:The soft soil foundation in mountainous area not only has the unfavorable engineering characteristics such as low bearing capacity, large settlement and long consolidation time, but also has the unique unfavorable characteristics such as complexity, concealment, non-uniformity, etc. The potential post-construction settlement is likely to endanger road structure and traffic safety. Therefore, it is necessary not only to carry on the reasonable treatment to the soft foundation, but also to carry on the accurate settlement forecast to the treated foundation, uses the related engineering data, selects the reasonable settlement forecast method and the model to forecast the foundation settlement to control the construction progress, It is of theoretical value and engineering significance to arrange construction organization, to determine the height of layered filling, intermittent time and preloading time to provide some guidance. Based on the key technology research and demonstration project of soft foundation treatment of Guizhou Mountain Expressway, the paper combines the soft foundation treatment method in the 18th contract section of the Junbi Expressway of Hangzhou and Rui Expressway. The settlement prediction method of CFG pile composite foundation for mountain highway is studied. This paper mainly completed the following aspects of the research: The main contents are as follows: 1. The CFG pile composite foundation is applied to the soft foundation treatment in mountainous area. The bearing capacity calculation, settlement deformation theory and settlement calculation method of the composite foundation are expounded, and the design calculation of the CFG pile composite foundation of the demonstration project is carried out. (2) this paper introduces the commonly used prediction methods based on measured data, and emphatically studies the principle, calculation process and application scope of curve fitting method, grey system model and neural network in this kind of method. Three representative methods are selected: Poisson curve method and BP neural network method. Under the guidance of its principle, the settlement prediction system is compiled by using MATLAB software, and the integration and application of the prediction method system are realized. Taking the measured settlement data of the project as an example, it is applied to the settlement data prediction system. (3) the settlement of CFG pile composite foundation is simulated by using Plaxis finite element analysis software, and the calculated results of settlement prediction system are compared with the measured settlement data. (4) the geotechnical centrifugation test of CFG pile composite foundation is carried out indoors to observe the deformation and settlement of the whole subgrade model, and at the same time, The results of geotechnical centrifuge test are compared with the prediction results of various methods in the prediction system and the numerical simulation results of finite element method. The settlement of CFG pile composite foundation is further analyzed and studied.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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