碎石桩加固液化粉土地基的数值模拟分析

Analysis of Numerical Simulation of Liquefiable Silty Soil Reinforced by Gravel Pile

碎石桩是目前工程中用于处理饱和粉土液化地基最有效、最经济、最普遍的方式之一,但是饱和粉土地基上碎石桩的抗震液化特性还有待于进一步研究。本文利用三维有限差分程序FLAC3D结合安徽某高速公路路基工程对碎石桩加固后的粉土地基的抗震液化特性进行数值分析。通过研究不同埋深距离碎石桩中心不同距离处的孔压增长、消散规律,得到高烈度地震荷载作用下碎石桩加固饱和粉土地基的合理桩间距及加固深度,为类似工程提供了借鉴。

The gravel pile technique is currently one of the most effective,economical,and widely used methods for dealing with saturated silt soil foundations.Many scholars have conducted re-search on the gravel pile mechanism with respect to saturated silt or sand foundations,and they have found some useful conclusions.However,further analysis is required on the seismic liquefac-tion characteristics of gravel piles in saturated silty soils.In this paper,we investigate the seismic liquefaction characteristics of gravel pile in the silt foundations of a number of Anhui expressway roadbed engineering projects.We performed numerical analysis using the three-dimensional finite difference program FLAC3D .By studying the pore pressure increase and the law of dissipation at different distances from the gravel pile center,we determined the reasonable pile space and the reasonable depth of gravel-pile strengthening in a saturated silty soil foundation during high-in-tensity earthquake conditions.These results can provide reference data for similar engineering pro-jects.