According to the seismic zoning map, the earthquake acceleration in maduo county is 0. 15g. According to the 2020 edition of Seismic Code for Highway Bridges, the seismic fortification intensity of bridges is 7 degrees and the seismic measures of bridges are level 3.

(1) Yematan Bridge, the seismic intensity (8.4 degrees) is higher than the fortification intensity (7 degrees), and the seismic acceleration may be more than twice that of the fortification earthquake, which is the direct cause of the bridge collapse.

(2) Changmahe Bridge, under normal circumstances, the seismic design and construction are carried out in accordance with the specifications, and this bridge should not collapse. Only after the earthquake intensity map is released by the Seismological Bureau of China, can the reasons be further clarified.

(3) Engineers should always be in awe and not take chances. Borrow a famous saying from Three-body: Weakness and ignorance are not obstacles to survival, but arrogance is.