Simulations of influences of properties of soil around piles on their bearing behaviors

The load transfer method is one of frequently-used means to study the bearing behaviors of piles. Supposing different parameters of piles and soil as well as loading conditions, a differential equation of piles and soil is established according to the condition of static equilibrium, where an exponential curve model is modified for load transfer function with softening or hardening of soil. The matrix displacement method programmed by MATLAB language is used to solve the differential equation, and it will give the resistances of side, axial forces and vertical displacements in different cross sections of piles. Simulation analysis is taken on the influences by the variation of the properties of soil around piles. The results show that the pile top settlement in topsoil of high strength is lower than that in subsoil of high strength under the same piles and loads, and the load proportions shared by tip will gradually converge to some level with the increase of loads. The top settlement and the tip resistance of pile are not obviously influenced by the degree of the softening or hardening of soil around piles at the beginning stage of loading. However, the higher the load is, the greater the difference between softening and hardening of top settlement and the load proportions shared by tip are. The increment of the general ultimate pile resistance will help improve the bearing capacity of the piles.