颗粒破碎对于珊瑚砂液化特性的影响

Effect of particle breakage on liquefaction characteristics of coral sands

利用GDS动三轴试验系统,对南海珊瑚砂进行了不同破碎度和不同动剪循环应力比下的等幅循环荷载试验,研究了破碎度,动剪循环应力比对南海珊瑚砂的液化特性的影响。试验结果表明:在一维固结试验条件下,随着固结围压的增大,珊瑚砂破碎度逐渐增大;对不同破碎度的珊瑚砂试样进行GDS动三轴试验,随着振动周次增加,在相同的破碎度下,随着动剪循环应力比的增加,试验孔压的发展速度逐渐加快,在相同的动剪循环应力比下,随着破碎度的增加,试样的孔压发展速度逐渐加快;饱和珊瑚砂动孔压的发展在动剪循环应力比为0.2的条件下的运用改进Booker模型拟合有较好的效果。

By using GDS dynamic triaxial test system,the cyclic loading tests of coral sands in the South China Sea were carried out under different breaking degrees and different cyclic shear stress ratios,and the breaking degrees were studied,effect of cyclic shear stress ratio on liquefaction characteristics of coral sands in the South China Sea.The results show that under the condition of one-dimensional consolidation test,the crushing degree of coral sand increases with the increase of confining pressure,and the GDS dynamic triaxial test of coral sand samples with different crushing degree increases with the increase of vibration cycles,under the same crushing degree,with the increase of cyclic stress ratio,the development speed of pore water pressure gradually accelerates,and under the same cyclic stress ratio,with the increase of crushing degree,the dynamic pore water pressure of saturated coral sand can be fitted by the improved Booker model under the condition of cyclic shear stress ratio of 0.2.