人工场地吹填珊瑚土抗液化强度大粒径动三轴试验研究

Experimental study on liquefaction resistance of hydraulic fill coralline soils at artificial sites based on large-scale dynamic triaxial apparatus

为探究岛礁工程中实际吹填珊瑚土的抗液化强度特征及相关试验技术,指出了一般珊瑚土液化试验中存在的非稳态饱和现象,提出了基于优化饱和方法与橡皮膜顺变性修正技术的珊瑚土单元体液化试验方法。对某岛礁工程场地实际吹填珊瑚土材料配制的4组不同含砾量的宽级配高压实度试样进行试验研究,获取了实际吹填珊瑚土抗液化强度曲线。通过与历史地震珊瑚土液化场地的地震动条件比对,复现了其原位液化的发生情况,验证了试验结果的合理性,并指出了我国南海岛礁工程场地的地震液化风险。通过分析含砾量对珊瑚土与陆相砾性土抗液化强度影响的差异性,进一步提出了基于含砾量的实际吹填珊瑚土抗液化强度修正公式,给出了其抗液化强度的简化估计方法。

In order to explore liquefaction resistance and related test technology of hydraulic fill coralline soils at artificial island and reef engineering sites,the phenomenon of unsteady state saturation in the liquefaction tests of hydraulic fill coralline soils was pointed out,and a cyclic triaxial liquefaction test method was proposed based on optimized saturation method and membrane compliance correction technology.Four groups of high-degree compaction samples with different gravel contents prepared by hydraulic fill coralline soils in an artificial island site were taken into the study,and the corrected liquefaction resistance curves of the studied materials were obtained.By comparing with the ground motion conditions of historical liquefaction sites,the occurrence of in-situ liquefaction was reproduced,and the rationality of the test results was verified.The study points out the liquefaction risk of the actual island and reef engineering sites in the South China Sea,analyzes the differences of the influence of gravel content on the liquefaction resistance of continental gravel soils and hydraulic fill coralline soils,proposes a gravel content based modified formula for the liquefaction resistance of hydraulic fill coralline soils,and provides a simplified estimation method for the liquefaction resistance of hydraulic fill coralline soils.