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干旱缺水已逐渐成为制约我国农业发展的主要因素,西北寒冷地区输水渠道由于渠基土的盐胀和冻胀造成了严重的渠水渗漏损失。为研究渠基土的盐-冻胀变形特性,本文选取北疆输水灌渠典型土体进行了不同干密度、不同Na_2SO_4含量和不同含水率条件下的盐-冻胀变形试验。结果表明:随着干密度的升高,土体盐-冻胀率先增大后减小,在某一干密度下盐-冻胀率最大。随着土体Na_2SO_4含量和含水率的升高,土体盐-冻胀率逐渐增大,土体盐-冻胀率与Na_2SO_4含量之间呈现二次多项式关系,与含水率之间呈现线性关系。与干密度相比,Na_2SO_4含量和含水率对土体盐-冻胀率的影响较大。
Drought and water shortage have gradually become the main factors restricting the development of agriculture in our country. In the cold region of Northwest China, serious water seepage loss caused by salt expansion and frost heave of canal foundation soil. In order to study the deformation characteristics of salt-frost heave in drainage foundation, this paper selected the typical soil of irrigation and drainage canal in northern Xinjiang for salt-frost heaving deformation under different dry density, different Na_2SO_4 content and different moisture content. The results show that with the increase of dry density, the salt - frost heave rate firstly increases and then decreases, and the salt - frost heave rate is the highest under a certain dry density. With the increase of Na_2SO_4 content and moisture content of soil, the salt-frost heave rate of soil increases gradually, and the quadratic polynomial relationship between salt-frost heave rate and Na_2SO_4 content shows a linear relationship with moisture content . Compared with the dry density, the Na_2SO_4 content and the moisture content have a significant effect on the salt-frost heave rate.