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高速铁路膨胀泥岩路基渗流及膨胀特性试验研究 |
张唐瑜1, 马丽娜1,2, 张戎令1,2,3, 王起才1,2, 王天双1, 王炳忠1
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1.兰州交通大学土木工程学院,甘肃兰州;2.兰州交通大学道桥工程灾害防治技术国家地方联合工程实验室,甘肃兰州;3.卡迪夫大学工程学院,威尔士卡迪夫
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摘要: |
以兰新高铁某典型膨胀泥岩路基段为研究对象,进行现场水平及竖向渗流试验,研究不同渗流方向下泥岩的膨胀及渗透特性。结果表明:水平及竖向渗流试验中,不同位置土样的体积含水率均经历前期快速增长、中期外凸弧线型缓慢增长和后期基本稳定这3个阶段。当泥岩发生水平渗流时,泥岩既发生膨胀,又发生软化,离注水管越近的土样膨胀量越大;离注水管远的土样朝已软化的泥岩方向释放膨胀能,导致其竖向膨胀量变小。影响水分在土样中渗透的因素主要有上部土样对下部土样的压密作用、基质吸力作用和重力作用。当泥岩发生自上而下竖向渗流时,土样最终体积含水率从上到下依次递减;泥岩膨胀会导致其渗透性减小;泥岩膨胀经历快速膨胀阶段、膨胀减缓阶段和膨胀稳定阶段。 |
关键词: 高速铁路 泥岩 渗流 膨胀特性 |
DOI:10.12170/201902007 |
分类号:TU443 |
基金项目:国家自然科学基金资助项目(51768033);长江学者和创新团队发展计划滚动支持(IRT_15R29);中国铁路总公司科技研究开发计划课题(Z2015—G001);甘肃省基础研究创新群体(145RJIA332) |
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Experimental studies on seepage and swell ability of expansive mudstone on high speed railway subgrade |
ZHANG Tangyu1, MA Lina1,2, ZHANG Rongling1,2,3, WANG Qicai1,2, WANG Tianshuang1, WANG Bingzhong1
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1.College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou;2.Key Laboratory of Road & Bridges and Underground Engineering of Gansu Province, Lanzhou Jiaotong University, Lanzhou;3.School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
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Abstract: |
Taking the base section of the typical expansive mudstone of Lanzhou-Wulumuqi High-Speed Railway as a research object, the horizontal and vertical seepage tests of the mudstone on the subgrade are carried out to study the swelling and permeability characteristics of the mudstone under different seepage directions. The research results show that during the horizontal seepage tests and the vertical seepage tests, the volume water content of the swelling soil samples at different locations all have three stages: rapid growth stage in the early period, medium-term convex arc type slow growth stage in the middle period, and basic stable stage in the later period. When horizontal seepage occurs in the mudstone, the mudstone both expands and softens, and the closer the mudstone is to the water injection pipe, the larger the swelling of the soil sample is. The soil sample farther away from the water injection pipe releases the expansion energy in the direction of the softened mudstone, and as a result, the amount of expansion becomes smaller in its vertical direction. The factors affecting the penetration of water into the soil sample mainly include the compaction effect of the upper soil sample on the lower soil sample, the effect of the matrix suction and the effect of gravity. When the vertical seepage occurs in the mudstone from top to down, the final volumetric water content of the soil sample decreases from top to down. The expansion of mudstone will lead to the decrease of permeability, and the expansion of mudstone will undergo the stages of rapid expansion, slow expansion and stable expansion. The research results can provide a reference basis for the construction of high-speed railway subgrade in the expansive mudstone area, and can provide technical reference for the construction of similar areas. |
Key words: high-speed railway mudstone seepage swelling characteristics |