动力排水固结法处理饱和软粘土地基的数值分析

发布时间：2018-05-05 04:12

本文选题：饱和软粘土 + 强夯　；参考：《中国石油大学（华东）》2013年硕士论文

【摘要】：饱和软粘土在强夯加固时，由于其低渗透性，土体中的水不能及时排出，导致“橡皮土”现象，不能达到土体加固的目的。通过改善传统强夯工艺，，在饱和软粘土体中设置竖向排水体与水平向排水体，提高软粘土渗透性能，有效的避免了“橡皮土”，实现了工程加固目的。在竖向排水体的选材方面，目前多采取塑料排水板方法。强夯+塑料排水板法已在工程中实践中积累了一套设计施工方法。根据工程经验，该方法的有效加固深度在10米左右，仍不能满足部分地基加固工程的需要，且孔隙水的排出仍相对缓慢，工期稍显漫长，而井点降水具有效率高，排水快的特点，另外在有效加固深度方面能弥补强夯+塑料排水板方法的不足，如何将两者有效的结合起来，对提高工程加固效果以及加快加固工期有非常重要的意义。本文在前人研究和实践的基础上，通过对强夯法与降水固结法加固机理的分析，探讨强夯+井点降水+塑料排水板方法处理软粘土地基中的可行性，着重分析了各环节的作用，提出了该法设计施工方法以及施工工艺与要点等方面的要求，并结合强夯+塑料排水板方法的工程实例，研究了施工过程中孔隙水压力与夯沉量等的变化规律，最后借助FLAC3D有限差分软件，对该实例进行了数值模拟，在此基础上，考虑降水作用，得出了水位变化下土体有关参数的变化情况，得出了一些结论，以供指导工程经验与理论研究。
[Abstract]:When saturated soft clay is strengthened by dynamic compaction, because of its low permeability, the water in the soil can not be discharged in time, which leads to the phenomenon of "rubber soil", which can not achieve the purpose of soil reinforcement. By improving the traditional dynamic compaction technology, vertical and horizontal drainage bodies are set up in saturated soft clay bodies, which can improve the permeability of soft clay, effectively avoid "rubber soil", and achieve the purpose of engineering reinforcement. In the vertical drainage material selection, the current plastic drainage board method. A set of design and construction methods have been accumulated in engineering practice by dynamic compaction plastic drainage board method. According to the engineering experience, the effective reinforcement depth of this method is about 10 meters, which still can not meet the needs of some foundation strengthening projects, and the discharge of pore water is still relatively slow, the construction period is a little longer, and the well point dewatering efficiency is high. The characteristics of fast drainage, in addition in the effective depth of consolidation can make up for the shortcomings of the dynamic compaction plastic drainage board method, how to effectively combine the two, to improve the strengthening effect and speed up the reinforcement period has a very important significance. On the basis of previous research and practice, this paper discusses the feasibility of treating soft clay foundation by means of dynamic compaction method and dewatering consolidation method, discusses the feasibility of dewatering plastic drainage board method in dynamic compaction well point, and emphatically analyzes the function of each link. The design and construction method of this method, as well as the requirements of construction technology and key points are put forward, and the variation law of pore water pressure and compaction volume during construction is studied in combination with the engineering example of dynamic compaction plastic drainage board method. Finally, with the help of FLAC3D finite difference software, the numerical simulation of this example is carried out. On this basis, considering the effect of precipitation, the variation of soil parameters under the change of water level is obtained, and some conclusions are drawn. To guide engineering experience and theoretical research.
【学位授予单位】：中国石油大学（华东）
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU472

【参考文献】