Steel Box Cage Throttling Technology In The Application Of Green Sand Reservoir Engineering Research

Closure is an integral part in the construction of hydraulic and hydroelectric project, concerning the success of the whole project. In recent years, the technology and theory of closure (river closure) have been developing rapidly and there are generally two basic methods of closure, banquette vertical closure and horizontal closure. With the development of the large transportation and excavation machinery at home and abroad, vertical closure gradually becomes the dominant method. In the closures of Ge Zhou Ba and Yangte River Three Gorges, vertical closure method was used, verified and proved to be suitable for the large flow river closure. However, technical difficulties and characteristics closure project varies from project to project, region to region. Therefore, it is worth further study and exploration of closure and a series of critical technology, especially for reservoir with high comprehensive difficulty, built on weak foundation, around big flow, tidal estuary.This thesis discusses the present situation and development trend of reservoir closure technology and takes Qing Cao Sha reservoir project for an example in order to study the technical features and main measurements of offshore horizontal closure for reservoir built on weak foundation, around big flow, high flow velocity, tidal estuary region. This thesis introduces in detail the research of two-dimensional hydraulic mathematical simulation, calculation and analysis of flow velocity of closure, tests and results of using physical and mathematical model to study the stability of closure structure, construction design, technology program and practice, and gives a summary of main achievements of all phases. Qing Cao Sha reservoir is the first large middle river nearshore reservoir built around tidal estuary region in China. There are lots of difficulties, such as big flow, high flow velocity, weak foundation and so on, in closure operation. So it is a representative project in relation to high technological difficulties and challenge. The key technology and solutions arising from the project are worthwhile to be promoted.