临—哈高速河套段砂砾改良盐渍土的路用性能研究

发布时间：2019-01-11 08:34

【摘要】：由于我国经济增长,导致公路与铁路的运输量迅速增加,中西部地区路网建设规模将得到进一步扩大。因为盐渍土具有特殊的工程性质,对公路路基的稳定性有一定的影响,从而严重影响了公路建设的质量。本文对临河至白疙瘩段的盐渍土进行研究。具体研究内容如下:(1)确定了临-哈高速河套段盐渍土的天然含水率,颗粒粒径组成等物理性质;判别出临-哈高速河套段盐渍土的主要类型;分析得出该段盐渍土的承载比、强度等力学指标。(2)基于河套平原地区盐渍土的工程特性及该地区的区域特点,采用砂砾改良盐渍土。通过对改良后盐渍土的颗粒粒径组成、液塑限和承载比等试验研究,总结出经砂砾改良盐渍土的工程性质变化规律;并通过强度等力学试验和冻融循环冻胀量及干湿循环等耐久性试验,对改良后盐渍土路基的力学性能和耐久性进行评价分析,最终确定砂砾改良盐渍土的合理配比为盐渍土:砂砾=1:0.6,为改善和合理利用当地盐渍土作为路基填料提供参考依据。(3)使用扫描电镜(SEM)对砂砾改良盐渍土进行微观实验观测,探讨分析砂砾改良盐渍土微观与宏观方面之间的联系。
[Abstract]:Due to the economic growth of our country, the traffic volume of highway and railway is increasing rapidly, and the scale of road network construction in the central and western regions will be further expanded. Because salinized soil has special engineering properties, it has certain influence on the stability of highway subgrade, thus seriously affecting the quality of highway construction. In this paper, the salinized soil from Linhe to Baikime is studied. The specific contents of the study are as follows: (1) the physical properties of the saline soil in the Lin-ha high-speed Hetao section, such as the natural moisture content, particle size composition and so on, are determined, and the main types of the saline soil in the Lin-Kazakhstan high-speed Hetao section are identified. Based on the engineering characteristics of saline soil in Hetao Plain and the regional characteristics of the region, the sand gravel was used to improve the saline soil. Based on the experimental study of particle size composition, liquid-plastic limit and load-bearing ratio of the improved saline soil, the variation law of engineering properties of the improved salinized soil by gravel was summarized. The mechanical properties and durability of the improved saline soil subgrade are evaluated and analyzed through mechanical tests such as strength test, freeze-thaw cycle frost heaving test and dry-wet cycle test. Finally, it was determined that the reasonable ratio of sand gravel to salinized soil was: sand gravel = 1: 0.6, In order to improve and reasonably use the local saline soil as subgrade filler. (3) the microcosmic experimental observation of sandy gravel modified saline soil was carried out by using scanning electron microscope (SEM). The relationship between microcosmic and macroscopic aspects of sand gravel improved salinized soil is discussed.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U414

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