Analytical solutions for consolidation of composite ground with gravel piles under multi-grade loading in equal rates

The expressway embankments were often constructed in several stages, which needed a long time. If the settlement of subgrades were calculated in the state of immediate loading, it is difficult to represent the relationship between consolidation and time. Because the rigidity of piles is larger than that of soils in the composite ground; the sand drain theory can’t be used directly. Based on the piles-soils mutual work theory, the mathematic formulas of consolidation of composite ground with gravel piles were established in the state of multi-grade loading in equal rates; and the analytical solutions were given in the loading state and the waiting state separately. The calculation results are in good agreement with the measured data in practical cases.