南黄海辐射沙脊群粉质砂土液化后大变形特性试验研究

Large Post-liquefaction Deformation Behavior of the Silty Sand in South Yellow Sea Sand Ridges

采用英国GDS动力三轴试验系统,针对南黄海辐射沙脊群粉质砂土,进行了不同相对密度、不同加载频率及不同固结比条件下的循环三轴试验,并在试样达到液化控制标准后进行固结不排水单调剪切试验,进一步探讨粉质砂土液化后大变形特性。结果表明:试样在动力三轴试验过程中达到液化控制标准并固结排水后,在整个单调剪切过程中,一直呈现出应变硬化的特性,产生很小的正孔隙水压力后,孔隙水压力向负的方向发展,试样始终处于剪胀状态,并最终达到稳定。

Using the GDS dynamic triaxial test system,the cyclic triaxial shear tests were per-formed on the silty sand under different relative density,loading frequency and consolidation rati-o.Samples that had achieved liquefied control standard received a consolidation undrained mono-tonic shearing test so as to get a further discussion on the silty sand liquefaction deformation char-acteristics.The test result shows that in the process of undrained monotonic shearing test,sam-ples had always presented the characteristics of strain hardening.The pore water pressure went into the negative direction after the small positive pore water pressure.The samples kept the state of dilatancy and achieved ultimate stability.