Research On Bearing Capacity Mechanism And Design Theory Of Pile Groups Subjected To Torsion

Large structures such as high-rise buildings, offshore oil platforms, and long-span bridges, inthe wind, wave loads, shock loads or even bring vehicles or machinery under horizontaldynamic load, various external forces passed through the structure of most likely cause of pilefoundation under torsional loading. With the rapid development of engineering constructionand large structures are emerging, if not fully taken into account in the design of torsionalload on pile forces impact will likely cause serious losses. But currently we do have verylimited awareness of the issues and research and, therefore, under reverse loading mechanismand research on design theory of pile bearing capacity, has certain theoretical meaning andvalue engineering.Major work in this article are as follows:⑴Combined with existing test results, discussion on single pile and group piles to the torsionstress and the characteristics of deformation which is carried out; summarized the torsioncalculation of single pile and group piles of existing theories.⑵Using three-dimensional finite element method for the calculation and analysis ofcylindrical torsion, develop the appropriate data analysis methods, by stress analysis to verifythe correctness of the calculation of torsion, while experimental results on centrifugalcalculations verified.⑶On by twist single pile, and3x3group pile foundation for has three dimensional numericalcalculation, respectively consider pile Zhou Tu for clay, and sand, and soft soil, and pilespacing for3D, and4.5d, and6D of situation, by calculation analysis known: as soil bodystiffness or pile spacing increases: Group pile reverse stiffness has obvious increases; basepile torque distribution uniform,but accounted for total imposed load contains of proportioncorresponding reduces; level force led has various base pile distribution anti-torque ofproportion differences, but this differences by soil body stiffness or pile spacing of effect issmall; torque of exists diagonal pile and edge pile level stiffness weakened effect obvious, itsrelative to single pile level stiffness of weakening degree can by both ratio forcharacterization. As the torsional load increases, apparent plasticity of soil mass around pilethrough regional, verify a shadow effect to a certain degree of development. ⑷Combined with numerical results of the analysis and design theoryof laterally loaded pilegroup, proposed design and calculation method of pile groups subject to torsional: Forcalculatingthe internal force of pile,we introduce two factorswhich is torsional coefficient ofefficiency and torque on the horizontal stiffness of pile weakening coefficient;torsioncalculation principles in accordance with the concrete components, establish torsionalresistance check method ofFoundationpile.