吉林省镇赉地区盐渍土动力特性试验研究

发布时间：2018-02-23 22:34

本文关键词： 镇赉地区盐渍土动强度动变形　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：地表土层易溶盐含量大于0.3%且具有溶陷、盐胀、腐蚀等工程特性的土称为盐渍土。盐渍土作为一种特殊土,在我国江苏北部,渤海西岸,华北平原,东北松辽平原的西部和北部,以及内蒙古等西北广泛分布。在吉林省西部地区广泛分布着一种以碳酸盐为主的盐渍土,这种特殊土因具有溶陷、腐蚀性、盐-冻胀等特性而对工程建筑有很大危害,因此引起了很多学者的重视。他们对盐渍土的基本性质,成因机理和工程病害产生机理及影响因素等多个方面进行了研究,并取得了一定成果。目前学者们在盐渍土的水盐运移机理、结构、力学等方面的研究比较集中,而在盐渍土动力特性的研究相对较少。在盐渍土地区越来越多的工程建设正在或者将要进行,因此研究盐渍土的动力特性对于这些工程建设来说具有重要意义。本文主要依托两个国家自然科学基金重点项目“寒旱区土体盐渍化HTSM多场耦合地质环境灾变演化机理与工程效应研究”(NO.41430642)和“松嫩平原分散土成因机制及水热盐耦合离子迁移模型研究”(NO.41372267)对吉林省镇赉地区的盐渍土进行基本性质和动力特性方面的研究。本文主要针对吉林省镇赉地区一号取样点40cm深度的土样展开一系列试验研究。首先,分别从粒度成分、天然密度、天然含水率、液塑限和易溶盐含量等方面进行了室内基础试验,对盐渍土样进行基本的定名和定性;在此基础上,进行了一系列盐渍土重塑土样的室内动三轴试验,研究了盐渍土在不同初始条件下的动强度曲线、动本构曲线、动弹性模量曲线和阻尼比曲线的变化规律,以及当含水率、易溶盐含量、冻融循环次数和围压等条件发生改变时对它们产生的影响。试验结果表明,镇赉地区盐渍土具有一定的特殊性,含水率、易溶盐含量、冻融循环次数和围压等条件发生改变时,对试样动强度、动本构关系和动弹性模量影响较大,而对阻尼比的影响相对不明显,阻尼比值范围为0.1~0.35。研究成果可以为该地区的工程建设提供一定的理论依据。
[Abstract]:Salinized soil is called salinized soil where the soluble salt content is more than 0.3% and has engineering characteristics such as solution, salt expansion, corrosion, etc. As a special soil, salinized soil is located in northern Jiangsu, the west coast of Bohai Sea, North China Plain, etc. The western and northern parts of the Songliao Plain in Northeast China, as well as the northwest of Inner Mongolia and so on, are widely distributed in the western part of Jilin Province. The salt-frost heaving and other characteristics have caused great harm to engineering buildings, which has attracted the attention of many scholars. They have studied the basic properties of salinized soil, the cause of formation, the mechanism of engineering diseases and the influencing factors, etc. Some achievements have been made. At present, scholars have concentrated their studies on the mechanism, structure and mechanics of water and salt migration in saline soils. However, there are relatively few studies on the dynamic characteristics of saline soils. More and more projects are being or will be carried out in saline soil areas. Therefore, it is of great significance to study the dynamic characteristics of saline soil for these projects. This paper mainly relies on two key projects of National Natural Science Foundation "soil salinization in cold and arid region, HTSM multi-field coupled geological environment disaster modeling". The basic and dynamic properties of salinized soil in Zhenlai area, Jilin Province, were studied in the study of chemical mechanism and engineering effect (no. 41430642) and the genetic mechanism of dispersed soil in Songnen Plain and the model of coupled ion migration between water, heat and salt (no. 41372267). A series of experimental studies were carried out on soil samples at 40cm depth at No. 1 sampling site in Zhenlai area, Jilin Province. The laboratory basic tests were carried out from the aspects of particle size composition, natural density, natural moisture content, liquid plastic limit and soluble salt content, respectively. A series of laboratory dynamic triaxial tests on remolded soil samples of saline soil were carried out. The dynamic strength curve, dynamic constitutive curve, dynamic elastic modulus curve and damping ratio curve of saline soil under different initial conditions were studied. The effect of the content of soluble salt, the times of freeze-thaw cycle and confining pressure on them has been studied. The test results show that the salt soil in Zhenlai area has some special characteristics, such as water content, soluble salt content, and so on. When the freeze-thaw cycle times and confining pressure change, the dynamic strength, dynamic constitutive relation and dynamic elastic modulus of the specimen are greatly affected, but the influence on damping ratio is not obvious. The damping ratio ranges from 0.1 to 0.35. The research results can provide some theoretical basis for the engineering construction in this area.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU448

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