Seismic Analysis On Super-Long Pile-Soil-Bridge Structure System In Liquefible Foundation

Pile foundations were damaged seriously during the past major earthquakes. Large amount of cost have been paid for the remedy of pile foundations after earthquakes because they are concealed projects. So to study super-long pile-soil-bridge structure dynamic interaction under earthquake is of significant academic meaning and great practical value.On the basis of systematical summarization of the current state of research on pile-soil-structure interaction, the damages of pile caused by earthquake and the mechanisms of piles failure, aiming at current problems between theoretical researches and practical situation of super-long pile-soil-bridge structure dynamic interaction, the researches are made as follows:â—‹1 Making the use of models and analytic methods for single pile-soil-structure, the relationship between dynamic influence depth and pile length is discussed. The dynamic response of finite pile, super-long pile and infinitely-long pile under horizontal harmonic loads is studied and it provides theoretical evidence to the simplifying calculation for super-long pile.â—‹2 Based on the shaking table model test of the soil-pile-structure interaction in liquefied ground, finite element numerical model is modeling. After the debugging of pile and soil material references, pile-soil interface references, boundary conditions, earthquake waves, and so on, to reliaze the better simulation of numerical analysis.â—‹3 The judgment standard of liquefaction in finite element is also been discussed. Besides experienced equation, the approximate pore pressure ratio is put forward in this paper. After setting two different cases in numerical analysis, the subtracting of total stresses is applied to liquefaction judgment.â—‹4 According to piles in macro seismic area, modeling super-long pile-soil-bridge structure dynamic interaction finite element model. The comparison of the horizontal and vertical displacement of pile-cap in static numerical analysis with the corresponding value in tests can be the correction judgment of the finite element model. After that, model super-long pile-soil-bridge structure dynamic interaction models to consider the effect of the superstructure of bridge to dynamic response.