CONSTRUCTION OF THE CHELSEA STREET VERTICAL LIFT DRAWBRIDGE UTILIZING MODERN CONSTRUCTION TECHNIQUES

摘要

The Chelsea Street Drawbridge is an existing single leaf bascule bridge which connects the cities of Boston and Chelsea, Massachusetts over the Chelsea Creek. The existing structure is being replaced with a vertical lift drawbridge due to the hazard to marine navigation posed by the existing structure as well as structural deficiencies. Through the use of modern construction techniques, the replacement of the movable bridge structure was executed while minimizing the impacts to the community. The installation of the liftspan truss was engineered as a pre-assembled bridge span constructed on land adjacent to the existing bridge. The upper tower sections of the bridge were also pre-assembled on the project and erected as single two-hundred ton column elements. Computer aided structural analysis was performed to review of the stresses induced on the liftspan truss due to the liftspan launch methods. Geotechnical analysis was also performed for loads induced by cranes and truss launch. The geotechnical engineering was also performed using computer modeling software. The innovations implemented through the use of modern construction methods and equipment during the construction of the Chelsea Street Drawbridge allowed the project construction team to reduce the risks to personnel while meeting project requirements.