摘要
为了解渠床含有夹砂层情况下的渠道渗漏规律,开展了均质土(砂壤土)和层状土(含夹砂层)条件下的室内渠道渗漏试验,对不同渠道水位、渠床土质结构影响下渠道渗漏量的变化以及土壤中湿润锋的前进过程进行了试验观测。选用饱和-非饱和土壤水、热和溶质运移模拟软件HYDRUS-2D,对室内试验过程进行了模拟验证及分析。结果表明,渠床中禁锢气体的存在可能阻碍湿润锋行进,使模拟结果产生误差。但总体来说基于Richards方程的饱和-非饱和土壤水分运动模型能够对含有夹砂层渠床的渠道渗漏及土壤水分运动进行模拟。当渠床中有砂质夹层时,湿润锋在交界面处会出现不连续的现象。夹砂层的阻水减渗现象在渠道水位较低时比较明显,当渠道水位较高时,夹砂层的存在甚至会增大入渗量。研究成果可为渠床含有砂层情况下的渠道防渗技术提供参考。
In order to understand the canal seepage process under the canal bed with sand interlayer,laboratory experiments were carried out to study the canal seepage in a soil tank with homogenous（sandy loam）and layered（with sand interlayer between the sandy loam layers）canal bed,respectively.The infiltration process and the advancement of wetting front were monitored under different canal water level for the two cases.Mathematical model was established accordingly.Using the saturated–unsaturated flow software HYDRUS-2D,the processes were simulated and examined. The results indicate that the soil water movement model based on traditional Richards Equation is able to depict the soil dynamics with sand interlayer,although the enclosed air may retard the advance of wetting front and bring error to the simulation result;the wetting front would become discontinuous if there was sand interlayer in the canal bed;the sand interlayer show some degree of hampering effect on infiltration if the canal water level is low,however with the increase of canal water level,the sand interlayer tend to enhance the canal seepage.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2010年第8期33-38,共6页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(50979105)
教育部新世纪优秀人才支持计划项目(NCET-07-0814)
北京市重点学科"水文学及水资源"建设项目
