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为拦截泥石流,世界各地设计并实施了多种坝型。在日本,多采用透过型格栅坝来防治泥石流危害。2005年日本学者中村?等人开始研制混合类加前扶垛型钢制开放式格栅坝。其结构做了调整,在原独立单体的基础上,增设横栏、加密立柱,构成桁架式格栅坝,研究其对泥石流的拦截效果。试验结果表明:在格栅坝上游侧有巨砾石堆积,在格栅坝内部没有堵塞。如果横栏的间隔是d95×1.0以下,与开口间隔没有关系,堵塞率在95%以上。对于不同类型的泥石流,如果横栏间隔在b2/d95=1.0,最下层横栏的间隔(b1/d95=1.0,1.25,1.5)没有关系。开口在b3/d95=1.5得到相同的泥石流拦截率。横栏间隔为b2/d95=1.0的格栅坝上层部分,没有堵塞,泥沙的拦截率急剧减少。辅助纵筋配置要求,可采用较细线材,纵筋的间隔必须紧密,才能对泥石流有拦截率。在泥石流多发地区,设置格栅坝,辅助纵筋的间隔设置为b1/d80=0.5,1.0,对泥沙拦截十分有效。
To intercept mudslides, a variety of dams have been designed and implemented around the world. In Japan, the use of transgressive grid dam to prevent debris flow hazards. In 2005, Japanese scholar Nakamura and others began to develop a hybrid type of open lattice dam with an abutment-type steel-backed former. Its structure has been adjusted. On the basis of the original independent monomer, cross bars and columns are added to form a truss lattice dam to study its interception effect on the debris flow. The test results show that there is a huge accumulation of gravel on the upstream side of the grid dam, and there is no blockage inside the grid dam. If the horizontal bar spacing is d95 × 1.0 or less, regardless of the opening interval, the clogging rate is 95% or more. For different types of debris flows, the spacing of the lowest horizontal bar (b1 / d95 = 1.0, 1.25, 1.5) does not matter if the bar spacing is b2 / d95 = 1.0. The opening at b3 / d95 = 1.5 gives the same debris flow intercept. Barrier spacing b2 / d95 = 1.0 The upper portion of the grid dam, there is no blockage, sediment cutoff rate decreased sharply. Auxiliary longitudinal reinforcement configuration requirements, the use of thinner wire, the longitudinal reinforcement interval must be close, in order to intercept debris flow rate. In debris flow prone areas, set the grid dam, auxiliary longitudinal ribs spacing set b1 / d80 = 0.5, 1.0, very effective for sediment interception.