渭北地区气候演变与黄土湿陷性异常——以陕西省旬邑县黄土工程性质为例

Climate Evolvement and Loess Collapsibility Abnormality In Region North of Wei River——with engineering features of soil in Xunyi County,Shaanxi Province

通过对旬邑县王家咀附近黄土剖面原状样品物理力学性质分析,结合磁化率指标对比,发现黄土的湿陷性成因时代导致的密度、孔隙比、压缩性等影响的同时,受气候演变等沉积环境的影响,在相对湿润~相对干旱转换的沉积环境下湿陷性土层中可能分布有非湿陷性夹层,非湿陷性土层的埋藏深度较夏季风湿润沉积环境具有一定滞后性。同时认为基础面选择及湿陷性土层处理等工程应用方面,可利用非湿陷性夹层的分布规律进行进一步优化。

Through analysis on the physico-mechanical properties of the undisturbed loess samples from Wangjiazui,Xunyi County and in combination with comparison of magnetic susceptibility,the loess collapsibility is impacted by the depositional environment such as climate evolvement while by density,porosity and compressive capacity,etc those are developed when the loess is formed.In the deposition al environment of relative humidity^relative drought transformation,the non-collapsible interlayer may be available in the collapsible layer.Compared with the depositional environment of monsoon and humidity,the cover of the non-collapsible layer in the relative humidity^relative drought transformation is with hysteretic nature.Meanwhile,optimization in engineering application such as foundation plane selection and collapsible soil treatment could be performed further in accordance with the distribution law of the non-collapsible interlayer.