Research On Construction Technology Of River Closure In Deep Overburden Layer

In order to fully develop the water resources and improve the living and ecological environment of the residents,with the progress of society and the development of the national economy,more and more water conservancy projects at home and abroad have been built on the middle and lower reaches of the rivers with deep overlays.With the construction of these projects,there are some new problems in the closure process under deep overburden conditions,such as the anti-erosion characteristics of the cover layer,the protective construction method of the cover layer,the selection and reduction of the cut-off throwing material under the cover condition The difficulty of intercepting measures,etc.,and only based on the previous construction experience and scientific theory can not completely solve these problems associated with the cover scouring,especially in engineering practice.Based on the study of several river bed closure technology,the minimum impact flow rate of the cover layer is 0.5m / s ~ 0.7m / s,when the water flow rate is greater than 0.5 ~ 0.7m / s,began to scour the river bed,the data is of great significance for the closure of the bottom of the sub-program design provides a data base;through the deep cover of the river bed foundation construction Technology research has come to a new river bottom construction technology that is "advanced retreat" undercover method,the bottom of the way to use the first block after blocking the combination of a way to block the use of a pre-into the Longkou,Longkou area The use of the method instead of the trestle or ship cast bottom,can reduce the difficulty of construction and construction costs,the construction technology to solve the difficult to use the ship,the trestle bottom of the problem is A new method of intercepting the dike at the end of the embankment is provided,which is effectively supplemented by the deep covering process.Size,quantity and so on,and combined with the Yellow River Haibowan water conservancy project design and hydraulic model test examples,to demonstrate the results of the study to further clarify the type of formation under the conditions of the choice of cut-off throwing need to consider the various factors and Which is of great significance and practical significance to the construction of the same type of engineering.At the same time,it is put forward that the implementation of the river closure in the deep-covered river bed is similar to that of the general river bed The concept of the two stages before and after the foundation is put forward for the first time,and the two stages of the cover are analyzed before and after the bottom of the cover.The study on the difficulty of the river closure is carried out.,More practical engineering,more operational;for two different stages to take corresponding measures to make the closure of the construction of a clear,the work can be carried out in an orderly manner,for the successful implementation of the closure of lay a solid theoretical foundation.The research results are scientific and practical,practical and instructive,which can provide technical reference and reference for similar engineering construction.It can provide guidance for the realization of safety and economy of cross-cutting construction under similar geological conditions,and has high theoretical guidance and Practical application value,economic and social significance.