It makes a brief introduction to option section of large-span aqueducts of irrigation channel in Ningxia,hydraulic calculation,aqueduct shell two-way prestress design,sidewall precast lifting,aqueduct pier,support and bored pile foundation design,precast and cast-in-situ construction control,etc.

Considering that both welding distortion and hot cracking are relative to the evolution of stress and strain in the welding process, a new technology named biaxial prestressing method is put forward to control the welding distortion and prevent welding hot cracking from the view of mechanics.

In view of particularity of the Beita Lake aqueduct, which crosses Tanglai channels, the two-way prestressed technology is adopted,and after sidewalks in large span structures of aqueduct is prefabricated and hoisted,secondary floor is poured in design and construction plan.

Test and theory study on bi-prestressed concrete beam;

Comparing analysis of experimental and theoretical study on bi-prestressed concrete simple beam;

The bi prestress concrete beam is prestress concrete beam spontaneous strike adopting tension prestress steel bar and precompressed prestress steel bar at one time to establish prestress on the section of the beam.

The objective of the research is to reduce the beam’s depth by bi prestress in order to save money and beautify landscape.