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Two nominal identical 4 m high steel strip reinforced soil walls varying only with respect to reinforcement layer length arrangement were constructed and instrumented in an indoor laboratory environment. A novel feature of the tests was a foundation arrangement that allowed for simulated loss of toe support. Both walls performed well at the end of construction (EOC). Predicted unfactored maximum reinforcement tensile loads at the EOC using four different load models were judged to be conservative (safe for design) based on comparison with measured loads for both walls. Reinforcement loads were observed to increase with decreasing toe support, particularly at the base of the walls. A fully developed composite soil failure mechanism propagating from the heel of the foundation bulkhead and behind the reinforcement layers was observed during excavation of the stepped base wall model. There were no visual indications of soil failure within or behind the wall with longer uniform reinforcement lengths. However, predicted EOC loads for this wall were exceeded for most layers after loss of toe support. Implications for the design, analysis and performance of steel strip reinforced soil walls with similar reinforcement arrangements constructed over initially competent soil foundations and then subject to loss of toe support are identified. [ABSTRACT FROM AUTHOR]

The paper investigates the accuracy of the coherent gravity method by using measurements reported in a large database of full-scale instrumented walls that was not available at the time the original method was developed. The new database includes data for bar mat, welded wire and steel strip soil reinforced walls. Measured reinforcement loads under operational conditions are compared with predicted values for bar mat and steel strip reinforced walls. The accuracy of the coherent gravity method as presented in the BS 8006 design standard is quantified by computing the mean and coefficient of variation of the ratio (bias) of measured to predicted loads. The paper shows that for steel strip walls the coherent gravity method is reasonably accurate for soils with friction angles less than 458. For granular soils with higher friction angles and bar mat walls, the current coherent gravity method is shown to be less accurate and, on average, non-conservative for design. Modifications to the method as currently described in BS 8006 are proposed to improve the accuracy of the method for bar mat reinforced soil walls and steel strip reinforced soil walls with high friction angle backfill soils. [ABSTRACT FROM AUTHOR]