两岸临河施工围堰壅水特性数值模拟研究

Numerical Simulation Study on Backwater Characteristics of Cofferdams on Both Banks Along River

对于施工范围在两岸呈带状分布的工程项目,当工期紧张时,需在河道两岸同时进行施工,对河道行洪会产生不利影响。为研究两岸临河施工围堰的壅水特性,建立了临河围堰并排和交错布置的平面二维水动力数值模型,比较了两种方案不同围堰宽度和来流量情况下的壅水高度变化特性。结果表明,并排布置壅水高度更高,最大壅水高度出现的位置受围堰宽度和来流量影响较小;两种方案最大相对壅水高度均随流量增加而增加,但增速显著减小,亦随阻水比的增加而增加,且增速呈快速上升趋势;最大相对壅水高度随围堰的宽长比增加而增加,且不同围堰布置方案随宽长比增加的特性有显著区别,在工程布置时需重视。

When the construction schedule is tight, construction needs to be carried out on both banks of the river at the same time, which will adversely affect the flooding of the river. In order to study the backwater characteristics of the construction cofferdams on both banks, a two-dimensional model was employed to establish a side-by-side and staggered hydrodynamic numerical model, and the characteristics of the backwater height change under different cofferdam widths and inflow rates of the two schemes were compared. The results show that the height of the backwater is higher when the cofferdam arranged side-by-side, and the position of the maximum backwater height is less affected by the width of the cofferdam and the inflow discharge. The maximum relative backwater height of the two schemes increased with the increase of flow rate, but the rate of increase decreased significantly, and increased with the increase of water blocking ratio, and the rate of increase increased rapidly. The maximum relative backwater height increases with the width-to-length ratio of the cofferdam, and there are significant differences in the characteristics of different cofferdam layout schemes with the increase in the width-to-length ratio. The project arrangement needs to be focused on this issue.