【作者】 高峰；

【导师】 吴中； 许永明；

【作者基本信息】 河海大学 ， 港口、海岸及近海工程， 2007， 硕士

【摘要】 近几年来我国高等级公路发展迅速，从已建软土地基高等级公路运行情况看，有的工后沉降量比较大，造成“桥头跳车”是目前存在的主要问题。真空堆载联合预压法是一种较好的软基处理方法。在我国的高等级公路建设中，已有许多将真空堆载联合预压技术应用于高等级高速公路软基处理的工程实例，但对真空预压机理的研究方面尚存在严重不足。为弄清机理，提高设计和施工水平，有必要作进一步深入的研究。本文在前人研究成果的基础上，结合现场试验首先对真空堆载联合预压机理进行了探讨，进而分析了影响真空预压最终加固效果的一些因素。然后研究真空堆载联合预压过程中的渗流问题，利用巴隆等应变固结理论，对其初始条件和边界条件进行修正，从而建立真空堆载联合预压的渗流模型，求出竖向排水体渗流量；通过变流量抽水非稳定渗流计算模型，计算抽真空过程中地下水位降深，进而研究真空预压加固区内地下水位变化规律。最后在分层总和法思想基础上，提出了真空预压加固地基固结沉降计算方法。分析了真空堆载联合预压加固地基总沉降的组成，对各部分沉降计算做了分析，并建议按联合堆载量大小来总结真空堆载联合预压加固地基沉降修正系数。更多还原

【Abstract】 In recent years, highway is developing rapidly in our country. The value of settlement after completion of works is high in the point view of built highway on the soft soil region, which produced a big problem called bumping at bridge-head. Vacuum combined with surcharge preloading is a good method to reinforce soft foundation. The method has been used to improve soft foundation of highway extensively. But the mechanism of vacuum preloading is not clear, it is necessary to study the method.Based on former research and the position experiment ,firstly the mechanism of vacuum combined surcharge preloading were analyzed and then some facts which affect the reinforce effect of the vacuum preloading are analyzed.Then research the seepage problem in the process of the vacuum combined with surcharge preloading, and built the seepage model of the vacuum combined with surcharge preloading based on Barron-presupposition, so the quantity of percolation of the vertical drain pile can be calculated, then according to unstable seepage mathematical calculation model, calculates the falls of groundwater level, and moreover does further research about change laws of groundwater level.At the last, on the basis of layered method, a method to calculate the consolidation settlement of vacuum preloading was deduced. The elements affecting total settlement during vacuum preloading consolidation were discussed. The principle that defined the coefficient of total settlement correction by the magnitude of combined loading was suggested.更多还原