Experimental Study On Water Flow Characteristics And Regulation Measures Of Complex Beach Group In Upper Reaches Of The Yellow River

Changsheng Wharf Downstream Beach?Shuigouyuanzi No.3 Beach section,a complex beach group,located in the upper reaches of the Yellow River in Gansu Province,also belongs to Wujinxia Reservoir Area of the Yellow River and one part of the second phase of shipping construction from Longwan to Nanchangtan,should be regulated.It is a continuous bending multi-beach and dangerous river course.It generally presents bending,shallow,urgent and dangerous characteristics.Changsheng Wharf Downstream Beach?Shuigouyuanzi No.3 Beach section is one of the main obstacle navigation group in the Yellow River Longwan to Nanchangtan section.There are 4 beach hazards in the river section,namely the Changsheng Wharf Downstream Beach,Shuigouyuanzi No.l Beach,Shuigouyuanzi No.2 Beach and Shuigouyuanzi No.3 Beach,and the safety of navigation through the ship is seriously affected.This paper mainly uses the river physical model as the main research method,combined with Gansu Provincial Transportation Department "Gansu River Water Transport Development Plan","Yellow River Wujinxia Reservoir Area and Longwan-Nanchangtan Beach Shipping Construction Phase II Project".Based on the renovation of Shoal Dangerous Groups from Changsheng Wharf Downstream Beach to Shuigouyuanzi No.3 Beach,this paper collects hydrology,sediment,geology,riverbed morphology,topographic maps,etc.,aiming at the channel grade of the Changsheng Wharf Downstream Beach?Shuigouyuanzi No.3 Beach.It is required to determine some important parameters in waterway regulation engineering.By making and constructing the abnormal scale river physical model,Water flow characteristic test under the natural state of the multi-strait dangerous river section is carried out on the basis of the similarity of the geometric similarity,water surface and velocity of the model.Characteristics of these hydraulic parameters were analyzed by observing water level,specific drop,velocity distribution and flow regime of different flow rates under natural conditions.After completing the model flow condition similarity verification and the experimental observation of the flow hydraulic elements at all levels under natural conditions,the channel regulation project test was carried out.Three different regulation schemes are put forward in this paper.By comparing and analyzing the navigable flow conditions of the reach before and after the different regulation schemes,it is shown that the third scheme can better improve water level,specific drop,velocity distribution and flow regime in the design main channel than the other two schemes,and meet the design channel scale and flow conditions required by the v-class channel standard.Therefore,the third scheme is recommended the implementation plan for the remediation project of the Changsheng Wharf Downstream Beach?Shuigouyuanzi No.3 Beach.In the recommended scheme,dredging measures are taken in the Changsheng Wharf Downstream Beach to meet the water depth requirement in the designed trough of the low water flow.Shuigouyuanzi No.1 Beach mainly adopts rectification measures such as cutting nozzles and filling grooves to improve the flow regime.Shuigouyuanzi No.2 Beach mainly adopts rectification measures such as cutting nozzle,dredging,and construction of submerged dam to adjust the velocity and specific drop of flow in the medium flow and flood discharge.Dredging and other measures are adopted to improve the flow regime in the Shuigouyuanzi No.3 Beach.After implementation of the regulation project,the navigation conditions have been significantly improved,and the remediation effect is favorable.It is proved that the remediation measures of the third scheme are scientific and reasonable through comprehensive comparison.