Influence of transient flooding on steel strip reinforced soil walls

Abstract

The paper presents the results of three full-scale tests that were carried out to investigate the influence of transient (cyclic) flooding on the performance of steel strip reinforced soil walls (SSWs). The walls were constructed to a height of 6m and then flooded and drained to about mid-height in four cycles. The walls were constructed with three different granular soils varying with respect to permeability, fines content and shear strength. Earth pressures and reinforcement loads were recorded at end of construction and at the end of each flooding cycle prior to draining. Hence, for the purposes of analysis, the walls were treated as either in a drained or flooded steady state condition. In-situ steel strip pullout tests were also performed. The wall facings were very permeable and thus prevented unbalanced hydrostatic and seepage forces from developing during drawdown that could increase reinforcement strip loads beyond drained condition values. The effects of soil type on measured loads at the connections and peak tensile loads located within the reinforced soil zone are identified. Measured reinforcement tensile loads at end of construction and at the end of peak flood stages are compared to predictions using different analytical models for the (dry) EOC condition. Similar comparisons are made using measured pullout test results and predictions using different pullout models. Implications for current design practice and wall performance in transient flooding environments are reported.