| With the development of the western region and the implementation of the strategy to revitalize the northeast, more and more constructions were built in permafrost regions.Pile foundations are the main form construction foundation in permafrost region. The pile foundations are supposed to bear both the static load and dynamic load. However, the dynamic behavior especially horizontal dynamic behavior of pile foundations is researched rarely in permafrost region-Based on low-temperature dynamic triaxial test, this article established three-dimensional dynamic interaction analysis model of pile-frozen soil by Finite-difference procedures, and the dynamic response of the single pile and pile groups in the level of harmonic loads was examined. The main conclusions are as follows:(1) It is a complex process of change that pile foundation bear dynamic load, in which the dynamic response of pile decreased along the depth; Pile-soil stiffness ratio is the important factors which impact the pile lateral dynamic performance; According to the calculations in this article, the nature of soil in the range of depth which is 10 times the pile diameter. As the elastic modulus of soil increased , the Displacement of the pile decreased;(2) Horizontal displacement of pile groups is mainly affected by the impact of pile spacing. With the increase of the pile spacing, the horizontal displacement of pile become small. In some cases, horizontal displacement of pile groups is less than the horizontal displacement of single which bears average load. It is associated with the pile spacing and the frequency of the load.(3) In some cases, dynamic stiffness of pile groups may be larger than the dynamic stiffness of single pile It is associated with the pile spacing and the frequency of the load. In the low-frequency phase, dynamic stiffness of pile groups is less than the dynamic stiffness of single pile which bears average load. With the increase number of piles increases, dynamic stiffness of pile groups become larger.(4) The distribution of shear forces and additional internal force at pile head depends on the pile spacing and location of pile. |
