【作者】 方神光； 吴保生；

【Author】 Fang Shenguang Wu Baosheng (State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic and Hydropower Engineering,Tsinghua University,Beijing 100084,China)

【机构】 清华大学水沙科学与水利水电工程国家重点实验室；

【摘要】 南水北调中线总干渠全长约1270 km,沿线设计有公路桥、铁路桥和排洪渡槽等建筑物共764座,若计算小型的农用桥梁,其数量更多。本文针对桥梁对渠首水位和水头损失的影响,采用堰流公式对该问题进行了模拟计算和分析。计算结果表明,桥梁对渠首水位的影响不能用每座桥梁水头损失的简单叠加。且在采用阻水能力较小的头尾半圆柱墩时,设计和加大流量下由764座桥梁引起的渠首水位增加分别仅为0.194 m 和0.238 m。对所有桥梁的水头损失计算比较发现,不同的桥墩形状造成的总水头损失相差较大,选用流线型、水流易于通过的桥墩形状可以节约相当部分的水头。更多还原

【Abstract】 The length of the Middle Route of Diversion Project from South to North China is about 1270 km and there are about 764 main bridges of different types without considering many little ones. Aiming at the effect of bridges on the elevation of water surface at the head of the Channel and energy loss,simulation and analysis were done by using weir formula.It indicated that effect of bridges on the elevation of water surface can’t be added up by using energy loss of every bridge simply.Extra eleva- tions of water surface contributed by 764 bridges under designed and increased flux are 0.194 m and 0. 238 m by using the type of semi-circular bridge pier.There are great difference of total energy loss un- der using different types of bridge piers and quite elevation of water surface can be spared by using types of streamline piers.更多还原