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膨胀土膨胀变形试验研究 |
李进前1, 王起才1,2, 张戎令1,2,3, 梁柯鑫1, 李航辉1, 刘爱仓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.兰州交通大学甘肃省道路桥梁与地下工程重点实验室,甘肃兰州
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摘要: |
为了研究不同注水方式对膨胀土膨胀量的影响,以及大尺寸重塑膨胀土浸水膨胀的变化规律,取某高速铁路地基膨胀泥岩重塑土样,进行开孔与不开孔的膨胀土浸水膨胀试验,并对不同厚度的大尺寸膨胀土试样进行浸水膨胀变形试验。试验结果表明:开孔注水与不开孔注水的膨胀土膨胀时程曲线有很大不同,开孔注水的土样膨胀时程曲线可以分为初始快速膨胀、减速膨胀、趋于稳定3个阶段;不开孔注水的土样膨胀时程曲线可分为初始缓慢膨胀、快速膨胀、减速膨胀和趋于稳定阶段4个阶段。分析得到土样损失体积率与膨胀量损失量的关系。不同厚度的大尺寸膨胀土试样膨胀时程曲线整体呈外凸形增长趋势,并且每级注水后,膨胀量也呈外凸形增长趋势;大尺寸膨胀土试样的真实膨胀量随着厚度的增加而增大,但增幅减小,真实膨胀量随着上覆荷载的增大而减小,减幅也降低。 |
关键词: 大尺寸 膨胀土 注水方式 |
DOI: |
分类号:TU443 |
基金项目:国家自然科学基金资助项目(51768033);教育部长江学者和创新团队滚动支持发展计划(IRT_15R29);中国铁路总公司科技研究计划(Z2015 G001);青年人才托举工程(2015QNRC001) |
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Experimental study on expansion and deformation of expansive soil |
LI Jinqian1, WANG Qicai1,2, ZHANG Rongling1,2,3, LIANG Kexin1, LI Hanghui1, LIU Aicang1
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1.School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou;2.National and Provincial Joint Engineering Laboratory of Road and Bridge Disaster Prevention and Control, Lanzhou;3.Key Laboratory of Road and Bridge and Underground Engineering of Gansu Province, Lanzhou
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Abstract: |
Expansive soil stone remoulded samples from the base of an expressway were taken for opening and non-opening expansive soil water immersion expansion test and large-scale expansive soil samples with different thicknesses were taken for water immersion expansive deformation test in order to study the influence of different modes of water injections on the expansion increment of expansive soil and the change rule of immersion expansion of large-scale remoulded expansive soil. The test results show that the expansion time interval curve of the expansive soil injected with water through opening and non-opening way is largely different. To be specific, the expansion time interval curve of the soil sample injected with water through opening way can be generally divided into three stages: initial fast expansion stage, decelerated expansion stage and stable expansion stage; on contrast, the expansion time interval curve of the other one through non-opening way can be divided into four stages: initial slow expansion stage, fast expansion stage, decelerated expansion stage and stable expansion stage. The relationship between soil sample loss volume fraction and expansion increment loss is analyzed to be Δδ=0.617ΔV+0.02. The expansion time interval curve of the large-scale expansive soil sample with different thicknesses is in a convex growth trend, so is the expansion increment after the water injection of each grade. The real expansion increment of the large-scale expansive soil sample will increase along with the increase of thickness but the amplitude of increase declines. The real expansion increment will decline along with the increase of overlying load, but the amplitude of increase declines. |
Key words: large scale expansive soil mode of water injection |