基于动三轴试验的压实黄土动强度特性研究

选取吕梁地区黄土,通过静压压实制备三轴试样,在GDS振动三轴仪上研究含水率、干密度和加载频率对压实黄土动强度的影响规律。结果表明:压实黄土的动强度及动强度参数均随振次的增加而减小,随含水率的增大而减小,随干密度和加载频率的增大而增大,动强度与振次之间的关系可用对数方程进行拟合。研究对黄土地区填方区基础建设具有重要意义。

Dynamic Strength Properties of Compacted Loess Based on Dynamic Triaxial Test

With ongoing western development, new urban construction in high-fill areas is a growing trend. Therefore, conducting research on the dynamic strength properties of compacted loess has important significance for the construction of large-scale infrastructure in loess areas of high seismic intensity. In this paper, with Lvliang compacted loess as the research object, we prepared triaxial specimens by static compaction. During the dynamic triaxial tests, we used stress control loading to apply dynamic load to the specimens. After sample loading, first, we applied a predetermined confining pressure to the specimen. Second, we applied a bias voltage to it. After consolidation was complete, dynamic stress was applied to the sample. When the specimen became damaged, we stopped loading. We preset the number of dynamic stress vibration times as 200. We performed many dynamic triaxial tests using dynamic triaxial apparatus to study the dynamic strength properties of Lvliang compacted loess including moisture content, dry density, and loading frequency. The results indicate that the dynamic strength of compacted loess decreases with an increased number of vibration times, and this relationship can be fitted to a logarithmic equation. The dynamic strength parameters of compacted loess decrease with an increase in moisture content and increase with increases in dry density and loading frequency. The dynamic cohesive force and dynamic internal friction angle decrease with an increase in the number of vibration times and then finally tend to stabilize.