陕北砂黄土地区滑塌变形特征及形成机制

Deformation Characteristics and Formation Mechanism of Sliding Collapse in Sandy Loess Area of Northern Shaanxi

为分析陕北砂黄土地区滑塌变形特征及形成机制,采取野外调查、理论分析等方法,分析砂黄土的工程地质特征,并对电力工程中的边坡问题进行研究。砂黄土物质组成具有细砂粒含量高、黏粒含量低的特点,导致其力学性质介于砂土与粉土之间。同时由于斜坡变形多发育于沟谷、冲沟两侧,受地表水影响明显,形成滑塌这一特殊的变形破坏形式。通过对不同发育程度滑塌的调查与监测,其变形演化过程主要分为坡脚卸荷裂隙产生、裂隙扩展滑动、坡肩贯通裂隙滑动等3个阶段,各阶段分别具有特殊的变形特征。

In order to research the deformation characteristics and formation mechanism of the slope in the sandy loess area of northern Shaanxi, take field surveys, theoretical analysis and other methods, analyze the engineering geological characteristics of the sand loess in research area and study the slope problem in the power engineering of the study area. The composition of sand loess has the characteristics of high fine sand content and low clay content, as a result, its mechanical properties are between sand and silt. At the same time, since most of the slope deformation in research area develops on both sides of valleys and gullies, it is obviously affected by surface water, a special deformation and failure form of sliding collapse is formed. Through the investigation and monitoring of sliding collapse of different developmental degrees, the deformation evolution process is mainly divided into three stages: the generation stage of the unloading cracks at the foot of the slope, the expansion and sliding stage of the cracks, and the sliding stage of the through cracks at the top of the slope,each stage has special deformation characteristics.