Numerical Simulation Analysis Of Inclined Loaded Piles In Double-layered Soil

Due to the advantages of high bearing capacity and small settlement,pile foundations are widely used in engineering practice.In addition to the vertical load?V?caused by the superstructure's own weight,the pile foundations of bridges,offshore drilling platforms,and wind power towers are often subjected to horizontal loads?H?caused by wind,wave,and drift objects.It is of great significance to reasonably evaluate the V-H joint bearing capacity of the pile by discussing the bearing mechanism of piles subjected to horizontal?H?and vertical?V?loads simultaneously.Therefore,based on the existing research work and achievements,this paper combines the National Natural Science Foundation of China?NO:51578231,51378197?and completed the following research work.A 3D numerical analysis model for a single vertical?V?,horizontal?H?,and V-H joint-loaded pilein single layer of slightly dense sand foundation and soft clay foundation respectively was established based on ABAQUS by selecting a suitable soil constitutive model?MC?and a pile-soil contact model?coulomb friction?.And then a corresponding 3D numerical analysis model for the double-layered soil composed of slightly dense sand and soft clay was established.Combined with the existing load test results and engineering examples,the reliability of the calculation results of the 3D numerical model is verified,respectively.Secondly,based on the validated and reasonable 3D numerical model,the vertical and horizontal ultimate bearing capacity(V_ult and H_ult)of pile was obtained by simulating the single piles of L/D=5 and 10 in the single-layer and double-layer foundations with the displacement control method,respectively.Subsequently,in order to simulate the working environment of the pile foundation under the combined effect of various horizontal and vertical complex loads,pile top loads at 0°,30°,45°,and 60°to the horizontal plane is appliedto the single pile?L/D=5,10?.The influence of the type of foundation soil,the inclination and the size of the inclined load,the layer thickness ratio of the upper and lower layers of the double-layered foundation,the L/D ratio of the length and the diameter of the pile on the horizontal displacement,the bending moment of the pile body,and the resistance of the soil on the active side and the passive side of the pile,and the effect of the horizontal stress and displacement in the foundation soil was analyzedbycombining with the calculation results of the inclined loaded piles under different soil conditions.At the same time,the envelope capacity of piles with L/D=5 and 10was obtainedbyusing the Probe method,and then summarized the characteristics of the pile's bearing capacity anddiscussed the failure mechanismof inclined loaded single pile in six types of double-layer foundations.Finally,combining withan engineering site load test,the numerical simulation analysis of the on-site trial pile load test was carried out with the ABAQUS numerical model which established in this paper.And then,compare and verify the numerical analysis results of this paper with the results of its field test.