Abstract: In this paper,the mechanical properties of the new steel aqueduct structure with steel truss beam-arch composite system across the canal are evaluated by means of numerical calculation and field test.The studied 110-metre steel aqueduct of Pihe River main canal of the Hanjiang-Weihe River Water Diversion Project has the largest span in the world.First,the strain and deformation of the key sections of the steel aqueduct structure under super varying water load are monitored through field water filling test,and the static performance of the structure is analyzed and evaluated by comparing the monitoring data with the numerical calculation results.Second,the natural vibration frequency of the structure under different water levels is tested by field pulsation test,and later compared with the numerical analytical results.The dynamic performance of the structure is also analyzed and evaluated.The results of water filling test demonstrate that the new steel aqueduct of Pihe main canal is in safe condition and the bearing capacity meets the design requirements.The research results could serve as a technical reference for similar projects.

Key words: main canal of Pihe River, steel aqueduct, steel truss, water filling test, mechanical properties, safety evaluation