Hydrodynamic Influence Dabanhu River Bridge Holes Widening Based on Two-Dimensional Finite Element Numerical Model

Dong Feng Li,Hui Nie,Fu Qing Bai,M Mostafa

doi:10.1051/e3sconf/20183803042

Dong Feng Li, Hui Nie + Show 2 more

Open Access

https://doi.org/10.1051/e3sconf/20183803042

Copy DOI

Abstract

In order to analyze the influence of bridge holes widening on hydrodynamic such as water level, a two-dimensional mathematical model was used to calculate the hydrodynamic factors, river network flow velocity vector distribution is given, water level and difference of bridge widening before and after is calculated and charted, water surface gradient in seven different river sections near the upper reaches of bridges is counted and revealed. The results of hydrodynamic calculation indicate that The Maximum and the minimum deducing numerical value of the water level after bridge widening is 0.028m, and 0.018m respective. the seven sections water surface gradient becomes smaller until it becomes negative, the influence of bridge widening on the upstream is basically over, the range of influence is about 450m from the bridge to the upstream. reach

Highlights

The river network flow of Shaoxing city and Keqiao district is slow and weak hydrodynamic. This is an important factor restricting the water environment of the river network, and this have a direct impact on flood control and drainage area water environment and water safety and sustainable development between local water environment and economic society
The initial water level and the initial velocity are given by measured tidal level or given value zero, initial conditions does not affect the precision of computed result
Many rivers arranged in a crisscross pattern of Keqiao District river network, Dabanhu river is an important channel connecting south and north plain river networks, the railway bridge go across on the Dabanhu river, because of the small bridge holes, water flow is obstructed

Summary

Introduction

The river network flow of Shaoxing city and Keqiao district is slow and weak hydrodynamic This is an important factor restricting the water environment of the river network, and this have a direct impact on flood control and drainage area water environment and water safety and sustainable development between local water environment and economic society. By widening the bridge holes width and with streamlined design of revetment works, these this can reduce flow resistance, increase flow velocity, cut down the water level, increase the river network water flow hydrodynamic. This is an important measure to enhance river networks. In this paper, based on the two-dimensional mathematical model, the river flow velocity, water level and other dynamic factors are numerical calculated and Analyzed

Boundary Conditions

River Network Survey

River Network Flow Velocity Vector Distribution