Numerical Modeling Of Soil-Pile-Slope Dynamic Interaction During Earthquakes

Pile is widely used in foundation plans. The seismic performance of pile groups is a focus problem of geotechnical engineering research. With the development of national economy and a larger number of underground plans, there are a lot of deep foundation pit projects in which piles are constructed in the pit bottom. The seismic design of pile group is influenced by foundation pit slope. So this research is significant.Based on the method of effective stress analysis and the sand model of multi-spring, the soil-pile interaction of pile group adjacent to soil slope is discussed in this dissertation. Geotechnical engineering software, FlipGenCN was used to construct simulation models combined with a practical example. Numerical experiments of group subjected to selfweight and static loading and earthquakes are conducted. And the following results are reached.(1) Performances of pile group are influenced by neighboring slope. And the pile-top horizontal displacement decreases with distance from slope. The value of pile -top displacement nearest closed to slope is max.(2) In the models subjected to selfweight and static loading, the bending moments of pile adjoining slope are maximum. Meanwhile, the changing is also large. The moments of pile decrease with increase of distance.(3) Two models subjected to strong earthquake, El Centro input wave model and Kobe input wave model, are conducted. And the lateral displacement and bending moments in pile closest to slope is max in the pile groups. However, the values are much larger than those in selfweight and static loading models.(4) The characteristics of pore water pressure are investigated for they are influenced factors of liquefaction earthquake-induced. It drew a conclusion that the pore water pressure gradually increases during earthquake. Comparing to the pore water pressure of sand below the soil slope, the value t of sand in the pile group is smaller.(5) The difference of the pile-soil is appearing during earthquakes. And the difference pile-soil of displacement is different with depth of soils. The values in lower and the bottom of pile are larger, and the relative displacement of soil-pile is mainly influenced by soils characteristics. The results from numerical simulation can provide an instructive guideline for seismic design and engineering design of the pile groups subjacent to soil slope.