【作者】 莫红艳；

【导师】 黄绍铿；

【作者基本信息】 广西大学 ， 岩土工程， 2002， 硕士

【摘要】 膨胀土是一种会给工程带来严重破坏的高塑性粘土，特别是对高等级公路路基工程和大型结构物所产生的变形破坏作用，往往具有长期、潜在的危险。本文从非饱和土力学的角度出发，以南宁市快速环道北环工程的K12+840～K12+920试验段膨胀土路基为研究依托，着眼于路基重塑膨胀土的工程特性，就高等级公路穿越膨胀土地区有关路基土性改良及施工技术问题进行相应的一些研究和探讨。本文研究的工作就下述几个方面展开：用石灰改良膨胀土的机理；通过室内试验确定掺灰的技术指标；在室内进行膨胀土掺灰的最大有效粒径的模拟试验，即钙离子水试验，由此总结出“粉—块”灰—土搅拌工艺的有效性、合理性和可行性；用数值方法对路堤使用期的湿度场进行模拟，并与路堤的强度—变形的计算域耦合，以检验土性改良的效果，从而探索一种描述改良膨胀土路堤运行工况的数值方法；用现有最常用的且费用最低的施工机具，对灰—土进行“粉—块”搅拌掺和及路基的填筑施工等。更多还原

【Abstract】 Expansive soil is one kind of high plasticity clay which may bring civil engineering heavy damage. It may make construction, especially the engineering of high-type roadbed, appear failure deformation. It is a kind of long-term latent danger to people’s life. Based on the theory of unsaturated soil mechanics and the properties of compacted expansive soil, this paper takes the northern part K12+840-K12+920 of Nanning urban highway as an example to studies some aspects of lime improvement of expansive soil and the technology of construction. The chief content of this paper is : the lime improvement mechanism of expansive soil; confirm the technical parameters of lime mixed from the results of test in laboratory; the scale-down test to define the maximum effective grain size of expansive soil when it is improved by lime; by building bank slope model and making use of finite element seepage flow program of saturated-unsaturated to calculate the examples, this paper simulates the humidity site in order to checkout the effect of lime improvement; studies and proves that it is feasible to mix blocky expansive soil and pulverous lime, and to fill roadbed by common construction machines etc..更多还原