• Title/Summary/Keyword: Nonhomogeneous backfill

Search Result 2, Processing Time 0.016 seconds

Active Earth Pressure against Caisson Backfilled with Crushed Rock and Sand (I) : Formulation (사석과 모래로 뒷채움된 케이슨에 작용하는 주동토압 (I) : 정식화)

  • Paik Kyu-Ho
    • Journal of the Korean Geotechnical Society
    • /
    • v.22 no.1
    • /
    • pp.63-72
    • /
    • 2006
  • Coulomb's theory has traditionally been used for the estimation of active earth pressure acting on rigid walls. However, many experimental data show that active earth pressures on rough, rigid walls are nonlinearly distributed. This is due to the arching effects produced by friction between the wall and backfill materials when the wall translates away from the backfill. Although there are analyses that take arching into consideration f3r a horizontal backfill surface and a vertical rigid wall, these analyses were derived for homogeneous backfill. Therefore, it is not possible to use these analyses for a caisson backfilled with crushed rock and sand, a common type of rigid wall for harbor structures. In this study, a new formulation for calculation of the nonlinear active earth pressure acting on a caisson backfilled with crushed rock and sand is proposed considering both internal friction angles and unit weights of the crushed rock and sand.

Active Eanh Pressure Against Caisson Backfilled with Crushed Rock and Sand (II) : Verification and Application (사석과 모래로 뒷채움된 케이슨에 작용하는 주동토압 (II) : 검증과 적용)

  • Paik Kyu-Ho
    • Journal of the Korean Geotechnical Society
    • /
    • v.22 no.2
    • /
    • pp.29-39
    • /
    • 2006
  • In the companion paper (Paik 2006), a new formulation for calculating the nonlinearly distributed active earth pressure acting on a caisson backfilled with crushed rock and sand is proposed, and it takes into account arching effects as well as difference in internal friction angles and unit weights between sand and crushed rock. In this study, in order to partially check the accuracy of the proposed equation, the results of the proposed equation are compared with the equation proposed by Paik (2003a) for caissons with rough surface and homogeneous backfill, and are compared with results of Rankine's theory for caissons with smooth surface and homogeneous backfill. In addition, a parametric study is performed to investigate the effect of $phi_{r}$, $phi_{s}$, $\delta_{r}$, $\gamma_{r}$, $\gamma_{s}$ and $\beta$ on the magnitude of active earth pressure acting on the caisson, and construction methods for minimizing active earth pressure on the caisson are also provided based on the results of a parametric study.