china zhongtie major bridge reconnaissance & design institute co., ltd. (brdi) was founded in 1950 especially to undertake the design of wuhanyangtze riverbridge, the first bridge across yangtze river. not long after that, brdi surveyed and designed the famous nanjingyangtze riverbridge, which won great reputation from all over the world and was awarded top prize for national science & technology progress. then she developed as a large specialized corporation for bridge reconnaissance and design. brdi comprises the first design department, the second design department, the third design department, south-east branch, the design research department, reconnaissance division and south-east bridge diagnosis and treatment center, who are responsible for bridge reconnaissance, design, design proof-check, scientific research, health diagnosis and treatment, construction supervision, project supervision as well as project business contract. in the past 50-old years, brdi has surveyed and designed more than 500 railway, highway, municipal and extraordinarily major bridges widely scattered all over china and more than 10 countries, of which 12 cross seas and 18 the yangtze river, 26 the yellow river.