南水北调中线工程桥墩壅水特性研究

Study on backwater characteristics of bridge-piers of Mid-Route of South-to-North Water Diversion Project

南水北调中线总干渠沿线设有阻水的槽墩、桥墩1145座，合理分析槽墩、桥墩的壅水大小，对于准确复核总干渠水面线、分析渠道输水能力具有十分重要的意义。本文利用Flow3D软件模拟了南水北调中线工程中常见的圆柱型桥墩的壅水特性，计算体型包括单排、双排和三排桥墩，桥墩的阻水比为5．0％-7．14％。分析表明，单排桥墩壅水的数值模拟结果与Yarnell修正公式计算结果相近；多排桥墩联合壅水值随桥墩排数的增加而增加。

As 1 145 aqueduct piers and bridge piers are there along the main channel of the Mid-Route of the South-to-North Wa- ter Diversion Project, it is quite important to reasonably analyze the magnitudes of the backwaters caused by aqueduct piers and bridge piers for correctly rechecking the water surface profile and analyzing the water conveyance capacity of the main chan- nel. The backwater characteristics of the normal column bridge piers of the mid-route of the project are simulated herein with the software of Flow3D, for which the types for the calculation include single row, double row and triple row piers with the water resistance ratios from 5.0% to 7.14%. The analysis shows that the result from the numerical simulation of the backwater of the single row pier is near that from the calculation made by the modified Yarnell formula, while the combined backwater value of the multi-row pier is increased along with the increase of the number of the pier rows.