Study On The Lock Approach Optimal Layout Of Caojie Navigation-power Junction

Chongqing cao-jie navigation-power junction is the largest cascade drainage project on Jialing rier, is one of ten key construction projects of national western development. There are so many ploblems, such as:large-scale of navigation-power junction, high head of lock, high flow of single-wide flood discharge, narrow river of damsite, complex river regime, that navigation conditions and general layout plan is the key issues of construction.This paper based on the national key project-Chongqing cao-jie navigation-power junction, used modern advanced technology and physical model test, combined with model analysis and prototype observation of similar projects, studied about navigation structures layout of this project. The main work and research results are as follows:(1) By the research of the first-line and second-line lock approach channel layout and approach entrance area of navigation conditions, made a number of optimization measures, improved navigation conditions of hub;(2) Considered of compressing reflux area, reducing the intensity of cross-flow, improving the flow of entrance area and so on, through comparative analysis, studied about how the length of guide wall and the form of dyke effect on navigation conditions, made some improvement measures, determined the appropriate length and form., think 0.27 is the better opening rate;(3) With the model test, studied about the highest navigable discharge, demonstrated and proposed the highest navigable discharge of cao-jie navigation-power junction, which is suitable for the characteristics of mountain rivers, and can meet navigation requierments and reduce the engineering investment too.(4) Based on code required flow rate range of vertical and horizontal, which is suit for the approach entrance area's navigation conditions of the lock, proposed measures to further improve the navigation conditions. Comprehensive analysis of first-line and second-line ship lock approach channel upstream and downstream navigation conditions, thought that the highest navigable discharge of cao-jie navigation-power junction can be increased from 1500 to 2000 cubic meters per second, under this navigable discharge ship can go into and out of the lock security.Main results of this project had been applied in the construction, saved investment of the project, economic and cocial benefits were significant.