干旱、半干旱区平原水库对坝后盐渍化的影响

发布时间：2018-03-29 05:00

本文选题：平原水库　切入点：土地盐渍化　出处：《干旱区研究》2016年01期

【摘要】：为了农业灌溉,干旱、半干旱区修建大量的平原水库,坝基多位于第四纪松散深厚覆盖层上,深厚覆盖层地基上平原水库的渗漏引起坝后地下水位抬升,造成水库下游大面积土地盐渍化,使许多土地减产甚至弃耕。通过对代表性平原水库的监测,分析水库对坝后地下水临界水位的影响程度,进而分析防渗措施的型式。利用有限元计算了深厚覆盖层透水坝基垂直防渗墙和水平铺盖时,坝基渗流量与防渗体尺寸的关系,并联合坝后排水体进行综合控制地下水临界水位,推导出控制地下水临界水位的水库防渗体尺寸计算公式。结合工程实例计算表明,选择合理的防渗体型式并结合排渗体联合控渗,可以从源头上控制坝基的渗漏量,使坝后地下水位控制在临界水位以下,防治坝后土壤的次生盐渍化问题。
[Abstract]:For agricultural irrigation, drought and semi-arid areas, a large number of plain reservoirs are built, and the dam foundation is mostly located on the loose and deep cover layer of the Quaternary. The leakage of the plain reservoir on the deep overburden foundation causes the underground water level to rise after the dam. A large area of land salinization is caused in the lower reaches of the reservoir, and a lot of land is reduced or even abandoned. Through monitoring the representative plain reservoir, the influence of the reservoir on the critical groundwater level after the dam is analyzed. The relationship between seepage discharge and the size of impermeable body is calculated by finite element method when vertical impervious wall and horizontal pavement of deep overburden dam foundation are used. Combined with the backwater of the dam to control the critical groundwater level, a formula for calculating the size of the reservoir impervious body for controlling the critical groundwater level is derived. By selecting a reasonable type of seepage control and combined with combined seepage control, the leakage of the dam foundation can be controlled from the source, the groundwater level behind the dam can be controlled below the critical water level, and the secondary salinization of the soil can be prevented.
【作者单位】：重庆三峡学院土木工程学院;重庆三峡水利电力集团股份有限公司;武汉大学水利水电学院;
【基金】：国家自然科学基金项目(51309262) 重庆三峡学院重点项目(12ZD20)资助
【分类号】：S156.4

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