Bridge Abutment Remediation – A Case Study

Abstract

Record-breaking rainfall events in parts of eastern Australia—particularly, most recently, in Queensland—resulted in severe flooding and property damage. Transport and Main Roads assets were not spared from destruction caused by these events. The severe rainfall and flooding resulted in debris slides, rockfalls, embankment slips, creek bank scours and erosion, bridge abutment failures, sinkholes, and reactivation of old landslides, causing closure of road networks. This paper focuses on the safety measures and remediation work that were undertaken on a failed abutment of a 40-year-old bridge on one of the major highways. The concrete abutment protection of the highway slipped and toppled over the bridge pier, causing concern for the stability of the highway above. As there was a prediction of further rain, it was deemed necessary to close the road below the bridge and maintain a close surveillance of the highway for potential hazards until an assessment was completed. As one of the main priorities of the department, these networks had to be reopened in a safe and timely manner for the public to resume use. The paper discusses the interim measures implemented and the design and construction of permanent remedial works. The paper also highlights the challenges of working in changing conditions, and the tight workspace adjacent to a busy, heavy traffic flow.