Research On Analysis Method Of Single Pile Under Lateral Load

With the rapid development of the national economy and the improvement ofscience and technology, civil engineering has also made considerable progress.High-level, ultra-high-rise buildings, the towering structure, large span bridges andthe construction of the city viaduct are also more and more. Pile is widely used inthe above structure because of its large carrying capacity, small deformation, goodstability characteristics. Pile foundation can bear larger vertical load, meanwhile,lateral loads created by wind, wave, earthquake, ship impact, dynamic of vehiclesystem also bring many problems to pile, so we have to consider the impact oflateral load on its carrying capacity in the calculation and design. As for single-pileunder lateral load, many scholars had given series of theoretical analysis methods,such as the limit subgrade reaction method, elastic subgrade reaction method,composite subgrade reaction method, elastic theory method, double-parameterfoundation elastic method, the NL method and numerical analysis methods. But, dueto the complexity of the problem, these methods are limited for application.This paper first summarized the advantages and disadvantages of the abovemethods, compiled MATLAB programs for the four commonly used methods,compared the differences between calculation results of the four methods and themeasured values by a typical test instance, and gives a further analysis of theirprogramming calculations difficulties and defects itself. Then, on the basis of theVlasov foundation model, the deflection differential equation of the lateral loadedpile on the double-parameter foundation was deduced. In order to simulate the soilto the pile reaction force, the compression springs of the foundation compressioncoefficient k and the shear springs of the foundation shear coefficient G were used,then the elastic model of a double-parameter foundation was established, and thevalue of the coefficient k and G were discussed. To consider the plastic deformationof soil, the sliders were connected in series to the compression springs to simulatethe elastic-plastic nature of the soil, then a double-parameter foundationelastic-plastic model was established, and ultimate resistance equation of soil werestudied. To facilitate the calculation, the finite difference method was used and the corresponding MATLAB program was established. For layered soils, consideringthe continuity of the interface, the MATLAB program based on thedouble-parameter foundation elastic-plastic model was wrote to verify theapplicability of the calculation method in this article on layered soils. Finally, usingthe double-parameter foundation, the factors that affect laterally loaded pile, such aspile diameter, pile length, pile modulus of elasticity, the soil elastic modulus,Poisson’s ratio and the top of the pile constraints were analyzed, and some usefulconclusions for practice were concluded.