甘肃省灌区都位于季节性冻土地区,为了适应基土的不均匀冻胀变形,并且在衬砌遭到冻胀破坏后,使修复比较便利,渠道一般采用预制板衬砌的型式。这种型式具有施工简便、进度较快等优点。但主要问题是砼板连接处的砂浆缝仍有一定的渗漏量,因而成为防渗的薄弱环 The irrigated areas in Gansu Province are all located in the seasonal frozen soil area. In order to adapt to the uneven frost heave deformation of the base soil, and to repair the frost heave after the lining is destroyed by frost heaving, the channels are generally of the prefabricated slab lining type. This type of construction is simple, fast progress and so on. However, the main problem is that mortar joints at the concrete slab joints still have a certain amount of leakage and thus become impervious weak rings