Comparison of measured and calculated temporary-prop loads at Canada Water Station

The loads developed in tubular-steel temporary props during the construction of the London Underground Jubilee Line Extension (JLE) station at Canada Water were measured using vibrating-wire strain gauges. Prop temperatures were monitored and their influence on the prop loads assessed. Wall movements were also measured, by means of inclinometers. In this paper, the temperature-normalized prop loads are compared with the results of modified limit equilibrium calculations. Prop loads and wall movements are compared with the results of a series of parametric finite-element analyses carried out using the program CRISP. On the basis of the finite-element analysis results, the design assumptions giving the closest correlation between measured and calculated prop loads and wall movements are identified.