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众所周知,单一的塑膜防渗,土料作保护层的渠道,具有防渗效果好、工程造价低、施工简便、材料运输量小等优点。但是,这种渠道边坡缓,流速低,仅适应于地面自然坡度小的平原灌区。反之,对于地面坡度较陡的灌区,渠道的稳定性很难满足,加之有占地多等不利因素,它的推广应用受到很大程度限制。近年来,一些水源较缺的灌区针对塑膜防渗而不防冲的特点,采用塑膜上覆盖非土料保护层的混合衬砌形式,即所谓的“双防”结构,来提高渠道的杭冲过水能力。根据塑膜、垫层、保护层相对位置
As we all know, a single plastic film impermeable, soil material for the protective layer of the channel, with good anti-seepage effect, the project cost is low, the construction is simple, small amount of material transport advantages. However, this channel slow slope, low flow rate, only adapted to the natural slope of the ground plain irrigation area. On the contrary, for irrigation areas with steeper ground slopes, the stability of the channels is difficult to meet. In addition, due to the unfavorable factors such as occupying more land, its application is greatly restricted. In recent years, some irrigated areas lacking water sources are characterized by impermeable and non-anti-seepage features of the plastic film. The hybrid lining, which is covered with non-soil protective coating, is called a “double anti-defensive” structure to improve the quality of the channel Rush over water capacity. According to plastic film, cushion, protective layer relative position