Question

In case of level back-fill with traffic load acting on it, the active earth pressure diagram will be


A Triangular

B Trapezoidal

C rectangular

D None of the above​

Answer 1

In engineering practice, for simplification, traditional methods such as those based on the Rankine theory and Coulomb theory are commonly used to estimate the active lateral earth pressure. However, both of the theories assume the backfills can extend to a sufficient distance in which the failure plane can fully develop, so that these approaches cannot take account of the influence of the backfill width behind the wall [1, 2]. This is not a realistic case; in fact, more and more cases with narrow backfill width are considered in recent years; e.g., rock formations are close to the wall in mountain area [3–6], mechanically stabilized earth (MSE) walls built in front of previously stabilized walls in order to widen the existed highways for traffic [7–9], and the pit supporting structure built near the existing building in urban agglomeration areas, all as shown in Figure 1. In these cases, the narrow backfill has an obvious influence on the full development of a failure wedge when predicted by the Rankine theory or Coulomb’s theory. It indicates the limitation of those methods in the utilization