平原地区桥涵设计流量确定及桥位选择

半干旱平原地区宽浅性河流主河槽流量占比较小,河滩流量占比较大,上下游河道地形地貌及跨河建筑物的设置对交叉处设计流量影响较大,设计流量如何确定,河滩处的流量如何分配,桥位如何选择是设计工作中的难题.以某铁路跨越位于坝上草原的二道营河为例,提出考虑上游河道阻水及流量错峰折减的分析方法;以某铁路跨越位于坝上草原的葫芦河为例,...

Flow Determination and Bridge Location Selection of Bridge Culvert in Plain Area

In the semi-arid plain,the peak flow of the main channel of the wide and shallow river is relatively small,while the peak flow of the river bank is relatively large.The topographical features of the upstream and downstream rivers and the setting of buildings across the river have a great influence on the design flow at the intersection.Calculation results of the commonly used flow calculation formula are often large.The way to determine the design flow,allocate the flow and choose the bridge location are difficult problems during the design work.Taking a railway crossing Erdaoying river in Bashang grassland as an example,this paper presents an analysis method considering the blocking of upstream river and the reduction of flow peak.By taking a railway crossing Hulu river in Bashang grassland as an example,a flow distribution method of each tributary of the river is carried out.The calculated results in the two cases are close to the actual investigation in field survey.Compared with the traditional calculation method,the comprehensive analysis method considering the upstream channel blocking water and the reduction of the peak flood staggering can reflect the actual situation of the basin more comprehensively.The design flow can be effectively reduced by about 20%~30%,which can help designer to determine the bridge location and bridge span,reduce the project scale and lower the cost.