毛细阻滞型腾发封顶系统中水分运移特性分析  

Simulation of Moisture Transport in Evapo-transpiration Covers of Shallow Capillary Barrier for Landfills

作　　者：杨清雷[1,2] 张金利[1,2] 杨庆[1,2] 杨钢[1,2] 

机构地区：[1]大连理工大学岩土工程研究所,辽宁大连116024 [2]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《水土保持通报》2011年第3期7-11,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"膨胀岩土的体积膨胀特性及其数值模拟"(50979015)

摘　　要：基于非饱和渗流理论,在考虑降雨与腾发条件下,建立了填埋场腾发(ET)封顶层非饱和渗流非稳态一维控制方程。采用大连市1976年的气象资料作为降雨(48 a汛期降雨最大年份)与腾发条件,以数值方法计算所建立的一维控制方程。通过变动参数计算并分析了植被、降雨强度、降雨持续时间等对ET封顶层水力学特性的影响。计算结果表明,所提出的浅层毛细阻滞型ET封顶层,在强降雨期间,可有效储存入渗雨水而不进入填埋场内部,在无雨期间,可有效释放土层中孔隙水。相对于无植被情况,有植被覆盖的ET封顶层对雨水入渗—腾发循环的作用效果更加明显。降雨强度和降雨持续时间对封顶层含水率变化有显著影响。随着降雨强度或降雨持续时间增大,土层含水率变化逐渐增强,封顶层由上至下逐渐达到饱和,说明该ET封顶层不适用于强降雨地区。A one-dimensional unsteady state governing equation was developed to simulate moisture transport on the basis of unsaturated seepage flow in capillary landfill covers in response to precipitation and evapo-transpiration（ET）.The numerical method was used to solve the governing equation with precipitation and ET data of Dalian in 1976（which has the most amount of precipitation in flood season in 48 years）.Parametric analysis was conducted to simulate variations in plants,precipitation rate and event duration.The results show that the proposed ET cover of shallow capillary barrier effectively stored rainfall during strong rainfalls and released pore water of soil between rainfalls.Compared with the condition of no plants,ET cover stored and releases water more effectively with plants.Precipitation rate and event duration had significant influences on water content variations of the covers.The variation ranges of water contents became greater as precipitation rate and event duration increased,and the covers become saturated gradually from up to down,which shows that ET covers of this kind are not suitable for areas with strong rainfall.

关 键 词：腾发 毛细阻隔 非饱和渗流 含水率 

分 类 号：TV131.2[水利工程—水力学及河流动力学]