多遇地震下古建筑地基土体振陷特性实验

Triaxial Test Research on Dynamic Settlement of Ancient Architecture Foundation Soil Under Frequent Earthquakes

古建筑因为历史建造和使用期长,加上使用期间的地震作用,多有倾斜,其地基所受应力处于不均匀应力分布状态.通过动三轴试验,针对两类软硬不同古建筑群地基土体,选定不同固结比及动应力幅值模拟地基土在不均匀应力作用下承受多遇地震作用,采集其变形累计并讨论土体各指标与应力水平间的变化规律,发现软土的振陷主要发生在振动后的再固结过程中,而硬土在类似小幅、多次振动下抗震性能较好,且上部负重越大振动对其影响就越小.分析将为现有倾斜状态下的古建筑的结构稳定评估提供参考依据.

Owing to a long period of time in construction and using, coupled with the influence of earthquakes, most of the ancient buildings have a tilt and soils are in a state of nonuniform stress distribution. By selecting different consolidation ratios and dynamic stress amplitudes, the dynamic triaxial test analogs two kinds of foundation soils, soft and hard, under uneven stress in small and frequent earthquakes to discuss the regulations between the parameters of soil and changes in stress level, and also provide references on stability assessment of ancient buildings in existing tilt. The results show the dynamic settlement of soft soil mainly occurs in the reconsolidation process after the vibration, while the hard one performs well under this circumstance and tends to be safer when its upper weights become larger.