A modified hyperbolicity-based load transfer model for nonlinear settlement analysis of root piles in multilayered soils.

Root pile is a new type of pile that improves the load carrying capacity by roots penetrating into soils. To carry out the nonlinear settlement analysis of such a root pile in multilayered soils, the hyperbolicity-based load transfer model is in this paper reformulated to account for the discontinuities between the segments with and without roots. The procedure to determine the model parameters for root piles is presented accordingly. The feasibility and reliability of such a proposed modified hyperbolic model for nonlinear settlement analysis of root piles in multilayered soils are verified by a numerical case and two real experimental cases. The numerical case study shows that the root pile does increase the pile load carrying capacity to some extent. In a parametric study based on this numerical case, it can be found that the bearing capacity of root piles increases along with the increase in the root number, size, depth and the elastic modulus of the surrounding soil. The loading test results on two real root piles sited in Chizhou Yangtze River Bridge, China, are used to further verify the proposed method. Comparing with other analytical methods, it is demonstrated that the proposed method incorporated with the proposed modified hyperbolic model can achieve a better agreement with the measured ones especially in a large loading stage. [ABSTRACT FROM AUTHOR]