Rigid Pipe Proof Testing under Excess Overfills with Varying Backfill Parameters. Section 1. Volume 6. Implementation as Recommended by the Research Unit

摘要

An 84-in. (2134-mm), reinforced concrete pipe culvert at Cross Canyon was heavily instrumented and tested at varying overfills ultimately reaching 180 ft (55 m). Quasi-theoretical internal stresses derived from measured soil stresses and a computerized neutral point analysis were compared with measured values. In this volume, four modes of failure described by Heger (28) are discussed and correlated with Cross Canyon results. Effective density coefficients are suggested for possible use in concrete pipe design. The paper recommends the use of Heger's design approach in conjunction with these coefficients and Caltrans' neutral point program (to be modified) for future pipe designs. The profiles of effective density coefficients vary with construction mode, overfill and pipe stiffness. Considerations used in establishing the profiles are provided. A design procedure is described in Section 1(6).3.