Assessment of concrete half-joints using non-linear analysis

The Kingston Bridge in Glasgow carries traffic across the River Clyde. Carrying an average of around 180 000 vehicles per day, it is one of the busiest bridges in Europe. The approach ramps to the Kingston Bridge include numerous half-joint geometries. These joints were designed in accordance with standards current in the late 1960s. A recent assessment to more onerous modern codes showed that some of the half-joints were not code compliant. In light of this theoretical inadequacy, a destructive load test was undertaken on a typical half-joint on one of the approach ramps that was being demolished and replaced. The data obtained from the tested half-joint demonstrated significant capacity above that predicted by the assessment codes. The results of the load tests were used to calibrate a non-linear finite-element model of the tested half-joint. Once confidence in the reliability of the non-linear model was established, various derivative models were used to reassess the half-joints in the Kingston Bridge Complex. This approach justified confidence that the half-joints' actual capacities were significantly greater than those calculated from the assessment codes and that they were sufficient to sustain the assessment loading.