Analytical Solutions For The Bearing Behavior Of Vertically Loaded Single Piles And Two-pile Groups By Considering The Pile-soil Interaction

Pile foundation is widely used for engineering due to its high bearing capacity,good stability,low and uniform settlement,convenient construction and strong applicability.In recent years,there has been a lot of results on load-bearing and deformation behaviors of pile foundation under working load.As for theoretical research methods,there is no rigorous analytical solution for vertically loaded single pile and two piles in homogeneous soil layer.On the basis of existed researches,more rigorous analytical solutions are established for vertically loaded single pile and two piles.Hence,the corresponding interactions between piles and soils are inves tigated.The following conclusions can be drawn:(1)The static and dynamic behaviors of the single pile and static two pile groups under vertical loading are introduced,respectively.The applications of analytical methods in static and dynamic analysis of single pile and two piles interaction are mainly introduced.According to the literature review,piles and soils coupling cannot be fully satisfied in existed analytical solutions for analysis static and dynamic responses single pile and two piles interaction in finite soil layer.The corresponding research plans are formulated as follows addressed the aforementioned problems.Based on the fictitious soil pile model and proposed modulus function,analytical formulas of bearing and deformation of single pile in finite soil layer are obtained.The main parameters on the pile head stiffness,the pile tip stiffness and the pile shaft axial force are investigated.(2)The complex function conforming method is proposed,moreover the analyt ical bearing and deformation solution of an arbitrary cross section embedded pile.The influence of the cross section shape on the pile head stiffness is studied.The equivalent Winkler modulus is investigated for the surrounding layered soil and the settlement of rigid rectangular foundation is calculated.(3)On the basis of analysis vertically loaded friction pile in finite soil layer,the dynamic response of friction pile under vertical steady excitation is further investigated.The critical factors affecting the pile vertical impedance and speed admittance are studied.(4)In order to study the interaction of two piles,based on the analysis of embedded single pile,application of Graf addition theorem on dealing with the boundary conditions of the piles and soil is proposed.The interaction factor of two embedded dissimilar piles are obtained.The geometries of two piles,the ratio of pile to soil and the slenderness affecting the interaction factor are studied.By means of superposition interaction factor,the static bearing capacity of pile group is investigated.