نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه سیستان و بلوچستان، زاهدان، ایران
2 گروه پژوهشی مهندسی رودخانه و حفاظت سواحل، پژوهشکده حفاظت خاک و آبخیزداری، تهران، ایران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Construction of spillway brings lots of expenditures for projects. In this study, the physical model of Germi-chai ogee spillway with curved plan and downward angle of convergence while the effective length of the spillway is reduced from the crest to the toe for several times, built in soil conservation and Watershed Management Research Institue. In this stage, a physical model of the prototype was prepared in the scale of 1:50 and was put to test. The physical model was constructed using polyethylene that is waterproof and Plexiglas was used to build walls and channels. In this article, experiments were performed for 8 different discharges making up to 25% to 150% of the design discharge of the prototype. The spillway demonstrated satisfactory performance up to the design discharge. Gradually an increase in the discharge led to a decrease in the performance of the spillway so that it was fully submerged and the downstream channel took control of the discharge. Gradually an increase in the discharge just slightly higher than design discharge, led to a decrease in the pressure at the crest while the pressure at the chute and toe increased. With higher discharges and submersion of the spillway due to regime changes, the pressure of the flow over the spillway reached from supercritical to sub-critical.
کلیدواژه‌ها [English]
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