Load relieving slab for strengthening masonry arch bridges - locates beneath carriageway surface and spans blocks sited beyond stringers

摘要

The relieving slab (20) is for strengthening masonry arch bridges and spans between two concrete blocks (16). The slab relieves the arch (11) of live traffic loads and may permit the upgrading of old "weight restricted" structures. The slab may be of reinforced concrete and is located immediately below the carriageway surfacing. The construction process may include first removing the carriageway to the required depth together with the parapets, and if necessary spandrel (12) areas. The concrete blocks or slab-seats (16) may then be installed, and may be founded on naturally occuring load bearing strata beyond the springers (10) of the arch (11). The slab spans the width between spandrels, and continuity reinforcement (17) may be provided between the blocks (16) and the slab ends.