Based on the Hewlett method for analyzing composite embankment with equal length piles

a three-dimensional hybrid soil arching analysis method is developed to explore the load sharing ratio of composite embankment with long and short piles under uniform pressure. The basic theoretical framework of three-dimensional hybrid arching analysis is established based on the vivid description of the stress concentration obtained from the finite element analysis. The soil arching effect coefficient is adopted to feature the incremental generation and the progressive failure of the arches

which changes with the increase of the length ratio. The equilibrium differential equation on the pile caps is established. The stress concentration ratios of the long piles and the short ones are calculated through solving system of equations including the equilibrium differential equation

boundary condition equation and relational expression of the two different soil arching effect coefficients. When the geosynthetics is taken into account

the reinforcement tension is calculated through the assumed deformed curves. And then a new equilibrium differential equation over the elevation of the pile caps is generated. Eventually

the results of centrifuge tests

in-situ tests and the finite element method are compared with those from the analytical method and are found to be in good agreement. Furthermore

parameter analysis is performed to evaluate the main influence factors on the soil arching. The analysis shows that the pile-soil stress ratio of the composite embankment with geosynthetics is significantly larger than that of the embankment without geosynthetics

especially when the cap coverage rate is relatively small.