Innovative Solutions for Strengthening Prestressed Concrete Railway Bridges and Culverts

Queensland Rail is currently upgrading the load capacity of its Blackwater to Gladstone coal rail line to carry wagons of 104 tonnes gross mass. Some 28 bridges and a number of box culvert structures require upgrading to achieve this objective. Because of the high cost of providing new structures on a deviated alignment, it was decided to strengthen the existing structures in situ. The most significant design problem associated with this decision is how best to achieve the strengthening with minimum disruption to coal traffic and to minimise the amount of alterations required to trackwork and overhead electrical equipment during the strengthening operation. A number of solutions have been investigated and trialled to try to achieve the strengthening with minimum disruption to the high density rail traffic which uses the line.