Deformation Characteristics of Loess Landslide along the Contact between Loess and Neocene Red Mudstone
Deformation Characteristics of Loess Landslide along the Contact between Loess and Neocene Red Mudstone
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DOI：
10.1111/j.1755-6724.2005.tb00875.x
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发表时间：
2005-02
期刊：
影响因子：
--
通讯作者：
Wen Baoping;Wang Si-jing;Wang Enzhi;Zhang Jian-min;Wu Yugeng;Wa Xinglin
中科院分区：
文献类型：
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作者：
Wen Baoping;Wang Si-jing;Wang Enzhi;Zhang Jian-min;Wu Yugeng;Wa Xinglin
摘要沿黄土与新近系红泥岩接触面的黄土滑坡是中国黄土地区广泛而频繁发生的滑坡之一。为了更好地理解这类滑坡的机制，通过现场监测和实验室物理模拟的方法，对一个沿黄土- NRM接触变形的受损黄土边坡进行了全面研究。现场观测和物理模拟结果表明，边坡变形将经历两个不同的过程：1)由坡头下降引发的侧向后退和垂直渐进传播；2)沿黄土- NRM接触的弱基底带的块体滑动与沿黄土内古土壤的小滑动渐行性分离。黄土- NRM接触的剪切破坏可能从中部开始，然后逐步向坡脚和内坡扩展。分析表明，边坡变形特征在很大程度上受边坡地形、黄土和古土壤的独特结构、物理力学性质以及黄土- NRM接触的产状和性质的制约。降雨通过与黄土和黄土- NRM接触土层的相互作用对边坡的变形特征有显著影响。此外，边坡上不合理的开挖方式和强度大大加剧和加速了边坡的变形过程。
Abstract The loess landslide along the contact between loess and Neogene red mudstone (NRM) is one of those that have occurred extensively and frequently in loess areas of China. To better understand the mechanism of this type of landslides, a distressed loess slope being subjected to deformation along the loess‐NRM contact was comprehensively investigated through approaches of field monitoring and laboratory physical modeling. Field observation and physical modeling shows that the slope deformation will experience two distinct processes: 1) laterally retrogressive and vertically progressive propagation, which was initiated by falling of the slope head; and 2) retrogressively separate mass sliding along the weak basal zone of the loess‐NRM contact with minor sliding along the paleosols within the loess. Shear failure of the loess‐NRM contact may initiate in the middle section, followed by a progressive propagation towards the slope toe and inner slope. Analysis reveals that the deformation characteristics of the distressed slope are largely constrained by slope topography, the unique structure, physical and mechanical properties of loess and paleosols, and occurrence and nature of the loess‐NRM contact. Rainfall has significantly influence on the deformation characteristics of the slope through its interaction with the loess and soil of the loess‐NRM contact. Additionally, improper style and intensity of cutting on the slope greatly enhance and accelerate the deformation course of the slope.