Experimental Study Of Engineering Properties For Lateral Restraint Pile With Composite Foundation Reloaded And Repetitive Unloaded

According to the interaction of the pile and the surrounding soil, the pile can be divided into active pile and passive pile. Active piles subjected to external loads directly and passed the stress to the soil initiative, in which the load on the pile is the cause, and soil deformation and movement is the result; passive pile is not directly subjected to external load, in which the soil movement is the cause, and the load on the pile is the result. During operation, the pile may have been a single active pile or passive, its performance is in the range of design considerations, however, accidental circumstances may appear which lead to the pile forced both active and passive, such as lateral surcharge load could generate an additional moment and additional load, which causing the structure was tilted even collapse. The traits of lateral restraint piles were studied under the condition of the composite foundation pile load through laboratory model experiments.This thesis analyzed the deformation problem of single-row pile with lateral restraint in the case of composite foundation loaded and unloaded in the pile side combining with laboratory model test methods, analyzed the model tests on single-row pile under lateral load different sizes, don't have load, different pile spacing and cyclic loading conditions, studied the variation of single-row pile's sway, axial force, bending moment and friction resistance with the lateral loading changes. The results showed that: under cyclic loading conditions, the maximum pile lateral variation value increased about 45.3% when pile spacing is four times the pile diameter than twice, and the influence gradually weakened when it comes to 5times.In the loading process, the axial force of lateral restraint pile, bending moments and negative friction resistance increased with lateral loads increase, and the forces of lateral restraint piles will not fluctuate great after several cyclic loading.This paper studied the influence of lateral load to pile deformation, proposed the design methods of single-row pile with lateral restraint under lateral surcharge loads by studied the influence of lateral load to pile deformation,consummated the design theory of single-row pile with lateral restraint, to provide guidance for engineering practice.