Experimental Investigation on Load Transfer Characteristics of Coupling Beam Pile Structure

For the defects of butterfly settlement of high-rise building foundations,a convenient and integral coupling beam pile structure foundation is proposed.To investigate the vertical load-bearing characteristics of the new foundation,indoor model tests were carried out and the properties were further calculated by the finite element method.A plastic damage model is established to analyze the vulnerable areas,which provides a reference for the design of structure.The test and calculation results show that the load-settlement curve of the coupling beam pile structure is slow-varying.Compared with the pile group,its settlement was reduced by 38.92%.The axial force is abruptly reduced at the connection between the beam and the pile.The coupling beam has an improved effect on the pile force,the pile axial force distribution is approximately the same at different locations,the coupling beam axial force is greater than the pile.The difference between the inner and outer shaft resistance of the coupling beam is large.The inner shaft resistance of the coupling beam is close to zero while the outer shaft resistance is significant.The beam can play a good load transfer role during the loading process by generating a significant amount of tensile force,and the coupling beam pile structure does not experience the butterfly settlement phenomenon when the traditional foundation is loaded.The main compression damage area of the combined structural foundation is the lower pile.The coupling beam is mainly subject to tensile damage.The corners of the coupling beam and the pile-beam connection are the vulnerable surfaces of the structure,which should be properly strengthened.