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三峡-葛洲坝两坝间典型滩段大流量下通航条件改善措施试验研究
Study on Measures to Improve the Navigation Condition of Typical Segment under Large Discharge between the Three George and the Gezhouba Reservoir
【作者】 章日红;
【作者基本信息】 天津大学 , 水利工程, 2011, 硕士
【摘要】 在充分收集研究河段基础资料和国内外研究资料的基础上,采用调查研究、资料分析、物理模型试验相结合的技术路线,对大流量复杂水流下三峡大坝至葛洲坝两坝间的通航安全条件问题进行了深入研究,获得了以下主要研究成果:(1)三峡大坝至葛洲坝两坝间河道呈现为典型的峡谷河道形态特征;汛期河道过水面积增加的速率小于流量增加的速率;流急、流态紊乱是滩险碍航的表观特征,河道的平面、断面、纵剖面形态是滩险碍航的根本原因;本河段滩险航道整治的总原则是:通过改变河床形态,调整水流结构和流速分布、消除或减弱不良碍航流态。(2)两坝间河段流速、比降、回流范围变化随着流量增加而增大;主流带宽度随着流量的增加而增宽,葛洲坝水位愈高主流带宽度愈窄。(3)石牌弯道采取整治工程措施试验研究表明:整治后各级流量下主流区宽度增加,回流带显著压缩,泡漩区表层过流量加大,有效过水面积加大,河道流速分布趋于均匀;泡水频率降低,泡强减弱,水流条件比现状条件下有了明显的改善。(4)改善通航条件非工程措施试验研究表明:提高葛洲坝坝上水位有助于减小两坝间河段的急流带宽度,对水流条件有一定的改善,能够达到改善通航水流条件的目的。
【Abstract】 Based on the analyses of extensive data collected from the related project and domestic and oversea research results, the combined methods of field investigation, data analysis, and physical model tests were applied to investigate the navigation safety under large discharge between the Three George and the Gezhouba Reservoir. Following main results were obtained.(1)The river channel presents characteristics of gorge type shape between the Three George and the Gezhouba Reservoir. In flood period, the increase speed of the discharge area is smaller than that of the discharge. The rapid flow and disorder flow pattern are apparent characteristics for navigation-obstructing due to rapids and shoals, and the basic reasons are the plane, cross-section and longitudinal profiles. So the total principle for the channel regulation is to adjust flow structure and velocity distribution through changing riverbed shape so that bad navigation-obstructing flow pattern is eliminated or weakened.(2)The velocity, gradient, backflow scope increase with the discharge. The width of main flow increases with the discharge, and decreases with the water level of the Gezhouba Reservoir.(3)The results of physical model test on regulation measures for ShiPai bend show that the main velocity area was widened and the circumfluence was compressed, the discharge in the surface layer of kolk boil area increases, the effective flow area grows and the velocity tend towards uniform. The appearance frequency of kolk boil decreases and the strength weakened. The flow condition is improved obviously.(4)The results of physical model test on non-engineering measures for improving navigation condition present that the rapid flow width decreases with the water level rise above the Gezhouza Reservoir, which can improve the flow condition and provides better navigation condition.