Transportation and erection integrated machine with displacement platforms and methods for erecting bridge using the same

A special launching carrier with variable position platform, comprising:

• a special carrier for erecting beam;
• and
• an under-bridge machine with a platform;
• wherein, said special carrier for erecting beam comprises
• a main beam, on which a lifting device is disposed;
• front wheel group and a rear wheel group respectively connected
• with and disposed under said main beam;
• said under-bridge machine with the platform comprises a under-bridge, and also comprises a front roller, a middle roller and a rear roller, disposed for supporting said under-bridge and operable to move along said under-bridge through rollers, and further comprises an erecting trolley and a set of foldable and elevatable variable position platforms installed on both sides of tail portion of said under-bridge, which allows said front wheel group to move from bridge abutment or bridge deck onto said under-bridge smoothly;
• said system further comprises a rotatable rear leg connected with and disposed under said under-bridge;
• said rotatable rear leg and said under-bridge are operable to be on the same line or perpendicular with each other by rotating said rotatable rear leg backward and outward;
• and said rotatable rear leg, said front roller, said middle roller and said rear roller respectively has a height regulating device installed thereon, in order to ensure an appropriate horizontal height of said under-bridge.