【作者】 包卫星；

【导师】 谢永利； 李志农；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2009， 博士

【摘要】 鉴于盐渍土工程特性及盐胀机理研究的不足,论文以内陆盐渍土工程性质研究为切入点,以揭示本质规律、服务工程为主要目标,在资料检索、收集、分析整理的基础上,结合当今我国公路工程盐渍土应用实际与理论发展趋势,基于野外观测、大尺寸模型试验、离心模型试验及GDS三轴试验等研究手段,通过系统试验、定性分析和定量计算,对内陆细粒盐渍土、粗颗粒盐渍土在不同条件下的工程特性、盐胀特征、溶陷规律、力学特性及工程分类等进行了系统研究。论文以GDS多功能三轴系统为试验平台,开展了不同土类盐渍土在不同含水量和含盐量条件下的强度特性试验,系统建立了盐渍土在不同含水量、含盐量条件下应力应变关系。选取有代表性的天然盐渍土,进行不同冻融循环后的水分、盐分迁移试验,从土类角度研究了天然盐渍土在多次冻融循环时的水分和盐分迁移规律及性状分析。应用研制的开放系统大尺寸模型试验,分析了不同冻融周期条件下硫酸盐、氯盐盐渍土盐胀特性及工程评价。针对目前粗颗粒盐渍土工程特性研究的现状,从土、水、盐、温、力五个方面对粗颗粒盐渍土的盐胀特性进行了深入研究。系统进行了硫酸盐渍土和氯盐渍土溶陷特性的离心模型试验研究,提出了盐渍土遇水溶陷的规律及机理。通过对典型区域的盐渍土颗粒组成统计分析、粗粒盐渍土试样制备粒径研究以及土水比与含盐量关系的研究,提出了合理的易溶盐试样制备粒径,优化了盐渍土易溶盐试验方法。通过对新疆典型盐渍土区域公路病害特征进行大规模的调研和观测,系统总结分析了新疆典型盐渍土区域公路病害特征及成因。通过开展野外调查、室内工程特性试验研究及现场试验研究,在分析和总结国内外有关盐渍土分类资料的基础上,紧密结合盐渍土地区公路建设的生产实践,系统地制定出以影响盐渍土工程性质的土类、盐分、含水量及温度等作为指标的盐渍土公路工程分类综合体系。论文研究成果对于完善有关规范规程,指导盐渍土地区公路建设,具有重要的理论与实际应用价值。更多还原

【Abstract】 In view of insufficient study on engineering characteristics of saline soil and salt heaving mechanism, the paper makes a start with the study on engineering characteristics of saline soil, aiming mainly at revealing rules and serving projects, introducing a systematic study on engineering characteristics, salt heaving characteristics, melt sinking rules, mechanics characteristics and engineering classification of fine granulated saline soil and coarse granulated saline soil under different conditions by combining the practice and theory of saline soil application for highway engineering in China today, on the basis of data retrieval, collection, analysis and reduction, using the research methods such as field observation, large-scale model test, centrifugal model test and GDS triaxial test in the ways of system test, qualitative analysis and quantitative computation.It is the first time to take multifunctional triaxiality system (GDS) as test platform to conduct strength property test of saline soil under different soil groups with different water content and salinity, and the (σ1-σ3)-ε1 relation curve of saline soil with different water content and salinity, the rules of volumetric changing with axial strain (ε1), the relation between ultimate strength and initial water content, and the relation between salinity and confining pressure are analyzed, thus the stress-strain relation of salty soil under different water content and salinity conditions is established systematically. Representative natural saline soil is selected for water and salt migration test after different freeze-thaw cycles, and the water and salt migration rules and character analysis of natural saline soil are researched in terms of soil groups after different freeze-thaw cycles. To prepare sulfate and chlorate saline soil samples in typical area and simulate natural drop in temperature and groundwater recharge by applying the developed open-system’s large-scale model test, and therefore, to research engineering characteristics of natural saline soil in subzones, and analyze salt heaving characteristics of natural sulfate and chlorate saline soil during different frost thawing periods, and engineering evaluation as well. Based on actuality of study on engineering characteristics of coarse granulated saline soil, it is the first time to use homogeneous design theory and prepare different fine grain-size filling materials, salinities and water contents, simulating natural temperature drop in winter with large-scale model test, and deepen the research on salt heaving characteristics of coarse granulated salty soil at five aspects of soil, water, salt, temperature and mechanics by means of statistical software. Centrifugal model test on melt sinking characteristics of sulfate and chlorate salty soil is conducted systematically for the first time, and the rule and mechanism of saline soil melt sinks are advanced, and the melt-sinking deformation behavior of different saline soil types under different conditions of water content and salinity is described systematically with comparative analysis of laboratory melt sinking test result with uniline or dual line. The preparation particle diameter of coarse grained saline soil are advanced though statistical analysis of particle composition in typical region and research on preparation particle diameter of coarse grained saline soil, and analysis on relation between soil water extract and salt content. The test method of soluble salt for saline soil are optimized. With large-scale investigation and observation on highway distress characteristics in typical saline soil area, to summarize and analyze systematically highway distress characteristics and genesis in typical saline soil area. With field survey, laboratory engineering characteristic test and site test, and based on the analysis and summary of saline soil classification data at home and abroad as well as production practice of highway construction in saline soil area, it is the first time to establish systematically a comprehensive system of saline soil highway engineering classification with indicators of soil group, salinity, water content and temperature which exert influence on saline soil engineering properties.Research papers has important theoretical and practical application value to improve the relevant norms of order and guide in Saline Soil Area road construction.更多还原