基于改进切线角理论的桃源县沉积岩滑坡预警阈值研究

Study on the Early Warning Threshold of Sedimentary Rock Landslide in Taoyuan County Based on Improved Tangent Angle Theory

摘要: 桃源县西部以及西南部主要为山地丘陵地貌，地形起伏较大，以碳酸盐类为主，山地滑坡灾害频发。为了减小区内滑坡灾害，实现滑坡灾害的准确预警，基于改进切线角理论，结合累计加速度，选取多个区域内已发生且预报成功的滑坡的多类型监测数据。通过绘制改进切线角图形、累计加速度–时间曲线，研究得出桃源县碳酸盐类滑坡蠕滑阶段的综合划分结果。确定临滑预警阈值判据为：T-t曲线切线角大于等于80˚、加速度绝对值大于0，并且能够持续较大波动的状态。此研究对于桃源县碳酸盐类滑坡的监测预警工作带来了较大的便利，同时为通过岩性建立预警模型提供了极大的参考价值。

Abstract: The western and southwestern parts of Taoyuan County are mainly mountainous and hilly landscapes, with large topographic undulations, dominated by carbonates, and frequent occurrence of landslide disasters in the mountainous areas. In order to reduce the hazards of landslide disasters and to achieve accurate early warning of landslide disasters, based on the theory of improved tangent angle, combined with the cumulative acceleration, multiple types of monitoring data of landslides that have occurred in the area and have been successfully forecasted are selected. By plotting the graph of improved tangent angle and cumulative acceleration-time curve, the study results in the comprehensive division of creep-slip stage of carbonate landslides in Taoyuan County. The critical slip warning threshold is determined as a state in which the tangent angle of the T-t curve is greater than or equal to 80˚, the absolute value of acceleration is greater than 0, and large fluctuations can be sustained. This study brings greater convenience to the monitoring and early warning of carbonate landslides in Taoyuan County, and provides a great reference value for the establishment of early warning models through lithology.