Method for transforming existing urban viaduct into interchange

The invention discloses a method for transforming an existing urban viaduct into an interchange. The method comprises the following steps of additionally arranging four cloverleaf left-turning directional ramps on the viaduct through widening the existing viaduct; arranging four right-turning directional ramps on the ground; symmetrically arranging four sunken squares in the block of each quadrant; connecting the four sunken squares with each other through square-shaped underpasses so as to form a slow-moving traffic system for non-motor vehicles and sidewalks; and skillfully combining three layers of interchange layouts such as the viaduct, the ground road and an underpass pedestrian pathway in an organic way. Various traffic paths do not interfere with each other so that problems of coexistence of people and vehicles and many hidden safety dangers are completely solved; and on the premise of assuring the traffic function, the floor space is greatly saved and the utilization value of the land is increased. Through the adoption of the method for transforming the existing urban viaduct into the interchange, disclosed by the invention, a problem that the interchange land is not enough for an urban viaduct center can be solved, the management of the space under the viaduct at the urban center can be also enhanced, the urban environment is improved and the urban grade is improved.