Key Construction and Control Technology of Long Span Self-anchored Suspension Bridge with Cable Before Beam

Abstract

AbstractShatian Bridge is a self-anchored suspension bridge with a main span of 320 m. It is constructed by the overall construction technology of “cable before the beam”. The main cable is temporarily fixed through the temporary anchorage system, and the main beam construction is based on the main cable. After the main beam is hoisted and welded, the main cable is temporarily fixed, and the tensile force of the main cable is transferred to the main beam to complete the system conversion. The bridge adopts permanent-temporary combined with temporary anchorage, effectively saving the cost. The lifting of the stiffening beam adopts inverted lifting technology. For the area of the short sling in the middle of the span, a non-full-length joist is designed to solve the problem of main beam lifting in the area of the short sling. During the construction, the steel beam of the anchorage section and the auxiliary pier are temporarily consolidated. The temporary cable actively balances the tension of the main cable with clear stress, which is convenient for construction control. Temperature welds are set at both ends of the closure beam section, which not only makes room for the hoisting of the closure beam section but also avoids the structural safety problems caused by the temperature deformation of the steel beam. The slip control method of cable strands based on water bag weight ensures that the main cable does not slip during steel beam hoisting. The length of the sling is increased through the extension rod, and the horn-shaped guide device is added to avoid sling damage caused by the sling colliding with the conduit mouth. Generally speaking, the construction scheme of “cable before beam” adopted by the bridge is reasonable and feasible, which enriches the construction technology of self-anchored suspension bridges and can provide a reference for similar bridge construction in the future.