晋西北区和晋中区大厚度黄土特征分析对比

Analysis and comparison of characteristics of thick loess in northwest and central Shanxi

山西省保德县霍家梁区位于晋西北黄土高原区,晋中猫儿岭区位于晋中盆地东北部黄土台塬区,均属于山西境内大厚度湿陷性黄土场地,均为风成沉积。前人对黄土的共性特征已做了系统的总结,但从晋西北区到晋中区,随着风速的逐渐降低,搬运力逐渐变弱,导致黄土的颗粒组成和物理力学性质也随着产生变化,对两区黄土的形成、成分、物理力学特征进行了分析研究,得出两个地区湿陷性黄土既有共同特性,也有其各自的地区特性;从晋西北区到晋中区黄土的颗粒组成基本由粗到细,黄土的颗粒组成、天然含水量、密度、天然孔隙比等指标对其湿陷系数的影响也有较大差距,文中给出了定量评价;从晋西北到晋中黄土的敏感性逐渐降低,并首次提出了湿陷临界系数的概念及相关方程公式。研究成果可为同类地区岩土工程勘察提供参考。

Huojialiang district of Baode county is located in the loess plateau area in the northwest of Shanxi Province,and maoling district of Jinzhong city is located in the loess tableland area in the northeast of Jinzhong basin.Both of them are typical collapsible loess sites with large thickness in Shanxi Province and are aeolian deposits.For the common characteristics of loess,the predecessors have made a systematic summary.From the northwest to the central part of Shanxi Province,the carrying capacity of the wind becomes smaller as the wind speed decreases.Through the analysis of the test data,it can be seen that the collapsible loess in the northwestern and central parts of Shanxi Province has commonality and individuality.From the northwestern part of Shanxi Province to the central part,the loess particles basically show a trend from coarse to fine,and the collapsibility sensitivity of the loess gradually decreases.In addition,the influence of the particle composition,natural water content,density,natural porosity ratio and saturation of loess on the collapsibility coefficient of loess is also different.In this paper,the concept of critical coefficient of collapsibility and its mathematical formula are put forward for the first time,and the research results can be used as a reference for colleagues.