垃圾填埋场毛细阻滞型腾发封顶工作机理及性能分析

发布时间：2018-04-10 16:28

  本文选题：填埋场 + 腾发封顶　； 参考：《岩土工程学报》2016年03期

【摘要】：毛细阻滞型腾发封顶目前主要用于国外干旱、半干旱地区,在湿润气候区的研究很少。在杭州市露天构筑毛细阻滞型腾发封顶模型,量测18个月中降水、蒸发和植被蒸腾下土柱透水量、地表径流量和土体含水率,得到该封顶在不同季节的响应,分析了毛细阻滞作用机理及其性能,使用水量平衡模型(HELP)和土壤 植被 大气相互作用模型(VADOSE/W)对试验过程中的水量平衡进行模拟,探讨了数值模拟存在的问题。试验过程中,共降水2361 mm,产生地表径流88.4 mm,透水67.4 mm,其他降水均在土层吸持与腾发交替作用下最终返回大气,由于试验地区多雨期与植被腾发旺盛期重合,毛细阻滞型腾发封顶在该地区具有良好性能。由于毛细阻滞作用,使得上部黏土中存储了更多水分用于后期腾发,从而减少了透水量,当毛细阻滞界面附近土体的体积含水率超过临界含水率时毛细阻滞界面被击穿,击穿是连续强降雨作用的结果。HELP和VADOSE/W均高估了地表径流和透水量、低估了腾发量,因为VADOSE/W能考虑毛细阻滞的机理,所以大致上VADOSE/W的模拟结果比HELP更合理和准确。
[Abstract]:Capillary block hair cap is mainly used in arid and semi-arid areas of foreign countries.In Hangzhou, a capillarity-retarded topping model was constructed in the open air. The soil column permeability, surface runoff and soil moisture content were measured during 18 months of precipitation, evaporation and vegetation transpiration, and the response of the cap in different seasons was obtained.The mechanism of capillary retardation and its performance are analyzed. The water balance during the experiment is simulated by using the water balance model (Help) and the soil vegetation / atmosphere interaction model (VADOSEP / W). The problems in the numerical simulation are discussed.During the experiment, 2361 mm of precipitation, 88.4 mm of surface runoff and 67.4 mm of permeable water were produced. The other precipitation was eventually returned to the atmosphere under the alternating action of soil absorption and transpiration, because the rainy period coincided with the vigorous period of vegetation transpiration.Capillary block hair cap has good performance in this area.As a result of capillary blocking, more moisture is stored in the upper clay for later hair release, thus reducing the permeability. When the volume moisture content of the soil near the capillary block exceeds the critical water content, the capillary block interface is broken down.Breakdown is the result of continuous heavy rainfall. Both Help and VADOSE/W overestimate the surface runoff and permeability and underestimate the transpiration, because VADOSE/W can consider the mechanism of capillary arrest, so the simulation results of VADOSE/W are more reasonable and accurate than HELP.
【作者单位】： 上海大学土木工程系;
【基金】：国家自然科学基金项目(51178260,51478256) 上海市教委科研创新项目(14YZ005)
【分类号】：X705
，

本文编号：1732036