【作者】 吴赛钢；

【导师】 何鹏；

【作者基本信息】 四川大学 ， 岩土工程， 2006， 硕士

【摘要】 由于软土地基含水量高、孔隙比大、压缩性高、抗剪强度低、渗透性小、承载力低,因此在这种地基上建造建筑物是十分不利的。砂井堆载预压法作为一种简单有效的软土地基处理方法已经在工程中得到广泛的应用。本文的研究围绕广安火电厂贮灰场挡灰坝坝基软粘土的处理展开。对于利用自身填筑重量作为堆载的堤坝建筑物,堆载预压法的一个关键性问题,就是坝体填筑速率的快慢问题。坝体堆载的大小与速率影响地基土的固结速度、沉降变形、承载力、工期长短以及堤坝的稳定安全性。通过室内实验及数值模拟分析研究了坝基软土层在打设砂井前后地基的固结沉降特性及强度增长特性,并在此基础上分析坝体的稳定安全性及确定坝体填筑的最佳堆载方案,为同类工程的设计及施工提供参考经验。论文主要工作内容包括:1.详细阐述了砂井堆载预压法及砂井固结理论的研究现状及发展情况;2.分析研究坝址区的工程地质条件,确定了坝基软粘土的地质成因及其厚度分布变化规律;3.进行坝基原状土样的常规室内实验,分析研究坝基土的常规物理力学性质;4.进行坝基土在不同固结度下的力学特性试验,分析研究坝基土的强度、变形及渗透性随土体固结度的变化规律;5.针对不同的加载方案,采用理论公式计算打设砂井前后地基的固结度、抗剪强度、沉降量以及坝坡的稳定安全系数,以此判断砂井地基的固结速率、沉降大小及稳定性是否满足要求,并在此基础上确定最优的坝体填筑方案;更多还原

【Abstract】 Due to high water content,high void ratio,high compressibility,low shear strength,low permeability and low bearing capacity of soft grounds,it is extremely disadvantageous to carry out constructed activities on the soft ground. As a simple and effective method of soft ground treatments,the sand drain preloading method has been widely used in construction projects.This dissertation is based on the treatment of soft foundation of the ash dam in ash storage yard of Guangan Thermal Power station. The key issue to the preloading method of dam which uses the self-weight to preload is the speed of the embankment. The magnitude and velocity of the loading have a strong effect on the consolidation velocity,settlement,bearing capacity of ground,construction period and the stability of dam slope. The Experimental study and numerical analysis are used to research the properties of consolidation settlement and strength increase of soft soils of the dam foundation before and after being treated with sand drain,and then to analyze the stability of the dam slope and finally to determine the best scheme to embankment. This research method could be the references to the design and construction of the future same kind project.The mainly contents are as follows:1. Elaborating the present research and development situations on the sand drain preloading method and consolidation theory of sand drain;2. Analyzing the engineering geologic conditions,the geological genesis of the soft soils and the thickness distribution of the soft soils within the area of the ash更多还原