Indoor Model Tests And Numerical Simulation Of The Influence Of The Depth Embedded Into The Cap On The Pile Lateral Bearing Behavior

As an ancient foundation, pile foundation is widely used in the modern engineerings, such as construction of bridges, roads, high-rise buildings and other projects because of its advantages of high capacity, strong rigidity, strong penetrating, small and relatively uniform foundation settlement. Under earthquake, pile often bear a greater lateral loads. Domestic and foreign scholars have focused on the increase of pile vertical bearing, few on the lateral bearing capacity of pile foundation. Although there are some scholars put forward the theory formulas of lateral bearing capacity of pile according to the experimental researchs, but few researches are against actual engineerings.Our country is an earthquake-prone country, and has vast land. Several big earthquakes in recent years have caused a large number of casualties and economic losses. Based on the experience of earthquake damage of piles found that the junction of pile and cap, the upper part of the pile, and under the bottom surface of cap are the weakest partd. Some scholars have conducted the experiments research about strengthened the nodes with the pile and cap. But the study of lateral bearing capacity of pile under the effect by taking into account both the interaction of pile-soil and embedded depth is still in its infancy.In this paper, effect of embedded depth on the lateral bearing capacity of pile is studied by indoor model tests and ABAQUS finite element analysis software,taking into account the effects of soil at the same time. The following conclusions are drawn out:(1) Pile embedded certain depth into cap can effectively improve theenergy dissipation capacity of pile- cap system, enhanced the integrity of the system and improve its seismic capacity.(2) The moment, the shear, the displacement along pile body, and the resistance of soil arround the pile increase with increasing of the embedded depth. Increasing the embedded depth of the pile into cap can increase the bearing the lateral force performance of pile. However, increament values increase first then keeping it steady with the embedded depth.(3) Increasing embedded depth can effectively improve the force distribution along pile, make pile more involved and improve the integrity of the pile. By comparing the force contour plots of pile body with each embedded depth, it been seen that the maximum stress in the pile body decreases with embedded depth increasing.(4) The reasonable embedded depth is about 1 time of the pile diameter through comparing the overall mechanical performance of the pile by taking into account both of technology and econamics.