The invention discloses a construction method for diversion of a
flood discharge channel, and aims to solve the problems that an existing
flood discharge channel is crossed with a newly-built sinking tunnel, the current
flood discharge channel crosses over a tunnel foundation pit, the tunnel foundation pit needs to be constructed and needs to be dismantled, and in order to ensure normal flood
discharge of a reservoir during construction of the tunnel foundation pit, the existing flood
discharge channel needs to be dismantled. And new diversion needs to be implemented before the flood
discharge channel in the range of the foundation pit is dismantled. The diversion construction method comprises the steps that firstly, four reverse construction wells are constructed on the two sides of a flood discharge channel on the periphery of a tunnel foundation pit, five steel pipes are erected above the reverse construction wells to serve as new diversion steel pipes, water is guided to the new diversion steel pipes at the
proper time, and finally the flood discharge channel to be dismantled in the range of the tunnel foundation pit is chiseled away. And the tunnel foundation pit can be normally subjected to foundation pit supporting, earth excavation and structural construction. Due to the fact that the new flow guide steel
pipe is erected above the tunnel foundation pit, supporting and excavation of the tunnel foundation pit are not affected, according to the method, the concrete flood discharge channel box is newly built according to the
specific gravity, the construction period is obviously shortened, and the flow guide steel
pipe can be recycled.