STRENGTHENING OF LANGLEYBURY LANE BRIDGE, HERTFORDSHIRE

Following the discovery of shear cracks at the interface of voided and solid sections of the spine beams, forming the deck in the main span of the three span Langleybury Lane bridge, temporary props were erected at its centre. The two existing raking piers were replaced with vertical ones and a permanent central pier was constructed to support the main span. Combinations of flat jacks and disc bearings were used to control reactions during transfer of the deck and subsequently to allow adjustment during the monitoring period. The deck could therefore be retained in a scheme providing positive benefits which conformed with current design and assessment standards. (A) For the covering abstract see IRRD 882313.