研究目的: 地下水通过毛细作用不断侵入路基,严重时会导致路基冻胀、盐胀等病害,而密实度、初始含水率、含盐类型及含盐量都会影响毛细上升高度。本文通过对纯石英砂掺入不同类型和含量盐分,开展毛细水上升高度试验研究,对比分析在不同粒径级配、初始含水率条件下的毛细试验结果,并拟合出上升高度预测方程。
研究结论: (1)毛细上升稳定高度随粒径减小而增大;在良好级配的条件下,细粒径含量的改变对毛细上升速度影响显著;(2)在4 000 min内,石英砂中掺入NaCl和Na2SO4会使毛细上升速度增大;(3)分别掺入两种盐分都会减小最终毛细上升高度,但NaCl的影响较小;(4)本研究成果可为控制毛细上升,处理盐胀、冻胀等病害提供借鉴和参考。
Abstract
Research purposes: Groundwater continuously invades the roadbed under the capillary action, which will lead to frost heave, salt heave and other diseases of the roadbed in severe cases, and the capillary rise height will be affected by soil density, initial moisture content, salt type and salt content. By mixing pure quartz sand with different types and contents of salt, the capillary water rise height test is carried out in this research. The capillary test results under different particle size gradations and initial moisture content are compared and analyzed, and the prediction equation of rising height is fitted.
Research conclusions: (1) The stable height of capillary rise increases with the decrease of particle size. Under the condition of good gradation, the change of fine particle size content has a significant effect on the rate of capillary rise. (2) Within 4 000 min, the capillary rising speed will increase when NaCl and Na2SO4 are added into quartz sand. (3) The addition of two salts will reduce the final capillary rise height, but NaCl has little effect. (4) The research result can provide support for controlling capillary rise and dealing with salt heave, frost heave and other diseases.
关键词
石英砂 /
毛细上升高度 /
含盐量
{{custom_keyword}} /
Key words
quartz sand /
capillary rise height /
salt content
{{custom_keyword}} /
中图分类号:
TU411.99
{{custom_clc.code}}
({{custom_clc.text}})
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 张永康,张田,张荣飞,等.高盐渍土地区某铁路路基填料选择研究[J].铁道工程学报,2016(9):10-13.
Zhang Yongkang, Zhang Tian, Zhang Rongfei, etc. Research on the Selection of a Railway Subgrade Filler in High Saline Soil Region[J].Journal of Railway Engineering Society,2016(9):10-13.
[2] Lu, G., X.D. Wang, Y.Y. Duan. Study on Initial Stage of Capillary Rise Dynamics[J].Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013(9): 95-103.
[3] 郝瑞. 基于AHFO的土中毛细水渗流与分布规律研究[D]. 南京:南京大学, 2020.
Hao Rui. Research on Migration and Distribution of Capillarywater in Soil Based on AHFO[D]. Nanjing: Nanjing University,2020.
[4] 栗现文,周金龙,赵玉杰,等.高矿化度对砂性土毛细水上升影响[J].农业工程学报,2011(8):84-89.
Li Xianwen, Zhou Jinlong, Zhao Yujie, etc. Effects of High-TDS on Capillary Rise of Phreatic Water in Sand Soil[J]. Transactions of the Chinese Society of Agricultural Engineering, 2011(8):84-89.
[5] 胡明鉴,张晨阳,崔翔,等.钙质砂中毛细水高度与影响因素试验研究[J].岩土力学,2019(11):4157-4164.
Hu Mingjian, Zhang Chenyang, Cui Xiang, etc. Experimental Study on Capillary Water Height and Influencing Factors in Calcareous Sand[J]. Rock and Soil Mechanics, 2019(11):4157-4164.
[6] TB 10035—2018, 铁路特殊路基设计规范[S].
TB 10035—2018, Code for Design on Special Railway Earth Structure[S].
[7] 张平,吴昊,殷洪建,等.颗粒级配对毛细水上升影响的研究[J].节水灌溉,2010(7):24-26.
Zhang Ping, Wu Hao, Yin Hongjian, etc. Effect of Particle Size Distribution on Capillary Water Upward Movement[J]. Water Saving Irrigation,2010(7):24-26.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
基金
国家自然科学基金(41772330);北京交通大学大学生创新创业训练计划资助项目
{{custom_fund}}