基于改进型斜率阈值法的滑坡降雨阈值分析

Analysis of Landslide Rainfall Threshold Based on Improved Slope Threshold Method

深入研究滑坡变形前的降雨量阈值,对后期滑坡的变形预测具有重大意义.本文在传统降雨斜率阈值预报的基础上,引入有效降雨量求斜率阈值,利用数学问题中求拐点思想,得出滑坡的"类破坏点",对比"类破坏点"在不同观测时段下平均累积有效降雨量斜率Dk,通过加权平均得出"类破坏点"的降雨斜率阈值D,并对滑坡后期变形进行预测验证,结果表明:通过斜率单变点确定累积位移的"类破坏点"为t1=57、t2=63、t3=81,计算观测时段n=6、时间间隔d=1下3个"类破坏点"的平均累积有效降雨量斜率Dk,后加权平均求出滑坡降雨斜率阈值D=10.83,同时对后40期降雨量监测数据进行验证,验证效果良好.为钥匙湾滑坡后期专业监测提供参考:当降雨量斜率大于降雨斜率阈值10.83时,滑坡可能发生失稳破坏.

It is of great significance to study the rainfall threshold before landslide deformation. On the basis of the traditional rainfall slope threshold forecast, the effective rainfall slope threshold is introduced, and the inflection point is obtained by using the mathematical problem. Compare the average cumulative effective rainfall slope of "class failure point" in different observation periods Dk, the rainfall slope threshold of "class failure point" is obtained by weighted average D, and the deformation of the landslide is predicted and verified.The results show that the "class failure point" of cumulative displacement is determined by slope single change point as the t1=57, t2=63, t3=81, calculation period n=6, time interval d=1 time interval. The average cumulative effective rainfall slope of the three "damage-like points " Dk, the weighted average to calculate the threshold of landslide rainfall slope D=10.83, at the same time, the rainfall monitoring data of the last 40 periods are verified, and the verification effect is good.It provides a reference for the professional monitoring of Yaoshiwan landslide in the later stage. When the rainfall slope is greater than the threshold of rainfall slope 10.83,the landslide may be unstable and destroyed.