At-rest earth pressure of overconsolidated cohesionless soil

Earth pressure theories occupy a paramount position in the field of geotechnical engineering. An experimental investigation of the at-rest earth pressure of overconsolidated cohesionless soil acting on retaining walls was conducted. A prototype model of a vertical rough wall, retaining horizontal backfill, was developed in the laboratory. The model was instrumented to measure the earth pressure at selected points on the wall, the total earth force acting on the wall, and the overconsolidation ratio (OCR) in the sand mass. Tests were conducted on walls retaining homogeneous overconsolidated dense, medium, or loose sands. Test results showed that the coefficient of at-rest earth pressure increases with the increase of the OCR. The present experimental results were used to examine the empirical formulas available in the literature. It can be reported that these formulas compared well with the experimental results for OCR values up to 3. An empirical formula is proposed to predict the coefficient of at-rest earth pressure for overconsolidated cohesionless soils. The results obtained by this formula agreed well with the present experimental results for all values of overconsolidation ratios.