Earth pressures on unyielding retaining walls of narrow backfill width

TLDR

Arching theory predicts a significant reduction in earth pressures behind retaining walls of narrow backfill width. The study aims to evaluate flexible subminiature pressure cells for measuring lateral earth pressures behind retaining walls of narrow backfill width. An extensive series of centrifuge tests was performed to assess these cells in the centrifuge environment and their application to measure lateral earth pressures. Although flexible cells exhibit hysteresis and nonlinear calibration, stiff diaphragm cells can reliably measure earth pressures, and measured lateral pressures on unyielding walls agree with Janssen's arching theory, which also provides reasonable estimates for backfills bounded by planes of differing friction. Key words: fascia retaining walls, silos, earth pressures, pressure cells, centrifuge modelling.

Abstract

Arching theory predicts a significant reduction in earth pressures behind retaining walls of narrow backfill width. An extensive series of centrifuge tests has been performed to evaluate the use of flexible subminiature pressure cells in the centrifuge environment and their subsequent use to measure lateral earth pressures behind retaining walls of narrow backfill width. Although the flexible earth pressure cells exhibit hysteresis and nonlinear calibration behaviour, the extensive calibration studies indicate that stiff diaphragm type earth pressure cells may be used with replicate models to measure earth pressures. Measurements of lateral pressures acting on the unyielding model retaining walls show good agreement with Janssen's arching theory. Tests on backfills bounded by vertical planes of dissimilar frictional characteristics indicate arching theory with an average interface friction angle provides a reasonable estimate of lateral earth pressures.Key words: fascia retaining walls, silos, earth pressures, pressure cells, centrifuge modelling.