摘要：Accurately calculating the active earth pressure of narrow backfill behind a retaining wall is crucial for safe construction and rational design. However, classical earth pressure theory cannot precisely forecast the nonlinear distribution of earth pressure behind a wall. This paper takes cohesionless soil behind a retaining wall as the research object to study the active earth pressure of narrow backfill behind a retaining wallassuming that the failure surface consists of an integration of logarithmic spiral and straight linesand takes into account the soil arching effect in the retaining wall translational mode. The expressions of the resultant active earth pressure and height of the resultant active earth-pressure application point are derived using the horizontal differential factor approach. The active earth-pressure calculation and experimental results of other methods were compared to verify the method validity, and the agreement was good, verifying the proposed method’s rationality. The effects of such parameters as the soil–wall interface friction angle δ and backfill aspect ratio X1/H on the active earth-pressure allocation and height of the resultant active earth-pressure application point are investigated using a parametric analysis. The outcomes reveal that the active earth-pressure value gradually grows as X1/H increases, and the nonlinearity of the earth-pressure allocation curve becomes apparent. The height of the resultant active earth-pressure application point decreases gradually and is always greater than H/3, and X1/H = 0.5 can be used as the critical ratio for finite and semi-infinite soils. As the soil–wall interface friction angle δ grows, the resultant active earth pressure declines significantly, and the height of the resultant active earth-pressure application point decreases gradually.
