【作者】 王沫涵；

【导师】 张骏；

【作者基本信息】 长安大学 ， 地质工程， 2007， 硕士

【摘要】 中国黄土分布很广,大量工程建设在黄土地区进行,而黄土所具有的特殊性质—湿陷性是黄土地区的最典型的工程地质问题,常常对工程建设具有极大的破坏性。对黄土的湿陷性进行更进一步的研究至关重要。本文针对黄土湿陷性的区域变化特点,自陕北—关中不同地貌单元下同一层位黄土取样七组。首先,在实验室进行常规分析及湿陷性测定,分析不同区域各项物性指标的变化趋势,及其与湿陷性存在的定性关系,得出自北向南湿陷性逐渐变小,天然含水量、密度、干密度、液限、塑限等物性指标增大,孔隙比、pH值和水溶盐含量变小。其次,对不同区域黄土进行切片,在偏光显微镜下观察其微结构,得出由北到南黄土微结构的变化为以细砂质接触胶结结构为主→粗粉砂质孔隙胶结为主→细—粗粉砂质基底—孔隙胶结结构为主,分析微结构变化与湿陷系数的相关关系;观察各种结构湿陷前后的变化特征,得出湿陷前后碎屑颗粒在水或外力的作用下其结构方式由支架接触逐渐向镶嵌接触过渡,孔隙比变小。再通过偏最小二乘法建立回归预测模型,对物性指标与湿陷系数进行定量分析,反映出物性指标与湿陷系数具有较好的相关性。最后,通过对微观结构与物性指标的分析,找出其对应关系,最终反映出两者在反映区域黄土湿陷性变化问题上的一致性。更多还原

【Abstract】 Loess is widely distributed in China, there are plenty of projects processed in loess area,and the special character of loess--collapsibility is the most typical engineering geologicalproblem ,and destructively to project. So, the further study of collapsibility is very necessary.The paper against the variety of loess collapsibility character has definite disciplinary in region, and divided Chinese loess to different region according to this disciplinary ,the collapsibility character is variable. This paper is sampling loess of the same depth from Northern ShaanXi - GuanZhong in loess plateau allusion to disciplinary of loess collapsibility , and 7 groups are sampled .At first ,the general analysis and collapsibility should be measured. Finding out the trend of every physics parameters (porosity ratio; natural moisture content; dry density; plasticity index; clay content).and qualitative relations between collapsibility and these parameters. Then, the quantitative analysis model of collapsibility and physics parameters is established using regress method. Consequently, speculate the trend of collapsibility based on the variable of physics index.Secondly, through analyzing loess slice of different regions, microstructure is observed under micropolaricope. and find out the trend of loess microstructure and characteristic of every structure collapsibility fore-and-after from north to south. Then find out the diversification disciplinary between microstructure and collapsibility.At last, finding out the corresponding relationship through analyzing microstructure and physics parameters, reflecting their coherence in loess collapsibility variety.This paper select physics parameters and microstructure as impacting loess collapsibility factors, and analyzing their relativity, finally, reflecting collapsibility through physics parameters and microstructure and processing collapsibility evaluation.更多还原