黄土崩塌的形成因素及其影响范围的确定方法

摘要

Loess collapse is the common disaster in loess area,and influences the safety of human’s life and pro-duction.According to the survey on site,it is believed that the main internal causes of loess collapse formation are the characteristics of loess soil and the joint cutting level,and the main external causes are the function of rainfall, human activity and biological activity.In terms of the common form of movement for loess collapse,the theory for-mula that determines the range of collapse body is presented under the condition that the collapse body falls freely and rolls.The example calculations show that,at the base of the ground level,no matter what the movement it is, the influence range of collapsing is 0.4~0.6 times of the slope height.As the slope steepens,the ratio for sliding distance and the slope height is enlarged accordingly.When the collapse body falls freely,the influence range of the collapse body has a relationship with the gradient of the collision point.When the collapse body slides in the slope, the influence range of collapse body has a relationship with the degree of slope.Research results can be used as the forecasting methods for the disaster range caused by loess collapse in loess area,which provides the theoretical basis for preventing loess collapse.%黄土崩塌是黄土地区常见的一种地质灾害，威胁着人类生产生活的安全。通过现场调查，认为黄土崩塌形成的内因主要为黄土土性特征、节理裂隙切割程度，外因主要为降雨作用、人类工程活动及生物活动。根据黄土崩塌常见的运动形式，提出崩塌体自由飞落及滚动情况下影响范围的理论公式。实例计算表明：若坡底地面水平，无论什么运动方式，崩塌影响范围为斜坡高度的0.4～0.6倍。随着坡度的变陡，崩滑距与斜坡坡高的比值也变大。当崩塌体自由飞落时，崩塌体的影响范围和碰撞点前的坡度有关。当崩塌体在坡面滑动时，崩塌体的影响范围和斜坡的坡度有关。研究结果可作为黄土地区黄土崩塌致灾范围预测方法，为黄土崩塌的防治提供理论依据。