黄土作为西北地区填埋场覆盖层的可行性及设计厚度分析

中国西北地区气候以干旱和半干旱为主，黄土广泛分布。首先介绍了西北地区3个代表性城市近50 a的气候条件和3类黄土的粒径分布及储水能力，在此基础上利用Chen、Benson等提出的水量平衡分析方法对黄土土质覆盖层在我国西北地区应用的可行性进行了探讨，并计算分析了单一型黄土覆盖层的设计厚度。分析结果表明: 西北地区夏季高温多雨植被生长茂盛而冬季降雨较少，降水和腾发作用有较好的同步对应关系，适合土质覆盖层的应用。采用黄土作单一型土质覆盖层的设计厚度在0.54～1.92 m之间，从干旱、半干旱到半湿润气候区，设计厚度逐渐变厚，其具体设计厚度与气候条件和黄土种类密切相关；在同一气候区采用粉性黄土所需厚度最薄，而采用砂性黄土则最厚。西北地区采用黄土作填埋场终场土质覆盖层具有技术可行性和良好的经济效益，值得进一步开展工程实践和更深入的研究。

Feasibility analysis of using loess as soil cover material for landfills in Northwest China and its analysis of design thickness

In Northwest China, the climate is mainly arid and semiarid and loess is widely distributed. This paper firstly presents the climate characteristics of three representative cities in Northwest China for nearly 50 years and the water storage capacities of the three types of loess. The water balance method proposed by Chen，Khire et al is used to evaluate the feasibility of using loess as soil cover material, and then the design thickness of monolithic loess soil cover is determined. The analyses demonstrate that: in Northwest China, hot rainy and the lush vegetation in summer compared with cold dry and the withered vegetation in winter , the intensities of precipitation and evapotranspiration have good synchronization, which is just application for soil cover. When the loess is used as soil cover material in the Northwest China, the design thickness of monolithic soil cover ranges from 0.54 to 1.92 m. The design thickness depends on the climate condition and the type of loess. From arid, semiarid to semihumid regions, the thickness becomes larger. For a given region, the design thickness for the silty loess is the least, and that for the sandy loess is the largest. The use of loess as soil cover material for landfills in Northwest China has advantages with respect to both technical and economical aspects. It is deserved to put the technique into engineering practice and call for more research.