Hydraulic Optimum Section And Application Of Multiple U-shaped Channel

Lining channels have a wide variety of section form. In order to adapt to the development and application of different section forms of prefabricated lining channel irrigation channels, this paper establishes the mathematical model of the optimal hydraulic section,studies the hydraulic optimum section of the four section of the U type lining channel, Using the Manning formula.The paper studies the hydraulic optimum section of the four section forms (Arc bevel shaped Ellipse linear form Parabola form Catenary linear).Then the typical design of the hydraulic optimum section of the four cross section forms is designed. The optimal order of design is obtained.The comparison shows that:in the design in terms of optimal hydraulic section is based, of U-shaped channel design, under the same flow conditions, circular arc bevel shaped channels over water the minimum cross section area, catenary channels too water area is the maximum cross section; catenary channel cross section depth, elliptic linear channel section excavation minimum depth; suspended chain linear channel section water maximum width, circular arc bevel edge shaped channel section surface width minimum. Also can get the following conclusion:hanging chain linear channel section area of the section water, water depth, water surface width for maximum, in practical applications are not recommended for use (except in exceptional circumstances); arc bevel shaped, linear elliptic shape channel the advantages of each, if the project to seek to conserve land, reduce the earth excavation, give priority to recommend using circular arc bevel shaped channel, if the project excavation depth limit, give priority to recommend using linear elliptic shape channel.All section of U-shaped assembly channels in the application also needed to in the vertical channel design, channel requirements in design under the condition of work, the channel will not occur scour or sedimentation balance and stable state. But in the application of U-shaped assembly channels often for a variety of reasons produced of slot between dislocation caused by channel flow instability occurs scouring and silting, prevent wrong of slot moving is also become the focus of this paper studies the application. In order to reduce inter slice shear groove and enhance the integrity of the assembly type channel, referring to the municipal engineering concrete drain pipe connection structure principle, using socket type belt ribbed U-shaped concrete canal connecting structure with the anti leakage and prevent the slot between the mutual dislocation, improves the U-shaped groove of the flexural capacity, strengthen the channel of longitudinal skid resistance ability, structure design and the connecting structure is reasonable, economical and practical, etc. advantages.