永登5.8级地震极震区黄土微结构孔隙性的定量研究

通过电镜扫描手段和计算机图像处理，对1995年永登5．8级地震极震区遭受地震影响和未遭受地震影响的黄土微结构变化的各项指标进行了对比试验和分析，并将分析结果绘成受震与未受震两种孔隙分布曲线。从这些曲线可以看出，不同地点的黄土孔隙分布特征不同；同一深度不同地点的孔隙分布亦有明显差异。对未受震(粒状架空孔隙结构)与受震(粒状镶嵌孔隙结构)黄土的微观结构进行了定量处理，其分析结果较好地解释了土体的工程性质。同时介绍了黄土微结构研究的方法和要求，通过对黄土微观结构的定量处理，揭示了黄土震陷性与黄土孔隙含量所占比例大小的内在关系，达到了确定黄土场地震陷量的目的，验证了利用微结构研究黄土结构变化的可行性。

Quantitative Research on the Porosity of Loess in the Meizoseismal Area of the Yongdeng M5.8 Earthquake

In 1995, an earthquake with M=5.8 occurred in Yongdeng, Gansu. By means of electronic microscope scaning and computer image processing, we made a comparative experiment and analysis of the microtexture between the effected and un-effected loess by the shock in the meizoseismal region, and drew their pore distribution curves respectively. The curves show that the pore distribution is different at various places and depthes. Meanwhile, we did a quantitative processing of the microtexture of the un-effected and effected loess (granular aerial pore structure and granular incrustation pore structure), the result of which explains the engineering characters of loess body much better. The research shows that through the quantitative processing of loess microtexture we can find out the relation of the loess sinking for earthquake and the ratio of the pore in loess and determine the sinking amount of loess.