It introduces the reinforcing design of concrete pile increasing section and constructing methods as well as structural measures to ensure concrete general pile work after reinforcement,meantime,it also introduces calculation and controlling in using steel stress after pile s reinforcement,in order to spread the application of increasing section reinforcement methods.

Based upon analysis of the meanings of engineering reinforcement several common reinforcement methods are introduced,which include enlarging-area approach,bonding steel plate method,CFRP strengthening method,strengthening method of masonry structure and so on,in order to widen people\'s understanding on engineering reinforcement method to ensure rationality of engineering.

This article discusses the application of the reinforcement method by increasing girder section and the fiber sheet reinforcement method using an engineering example of reinforcement and reconstruction of an in-service reinforced concrete bridge.