摘要
三峡库区自2003年蓄水以来,库区有大量滑坡监测累积位移曲线呈阶跃型,此类滑坡在外界影响因素下集中在某一时间段内变形量大,其机理复杂、稳定性判断和预警难度大.通过研究滑坡的变形特征及诱发因素,有助于评估滑坡的稳定性,并构建合适的预警模型.本文以白家包滑坡为研究对象,综合分析15年人工和4年自动GNSS地表位移监测数据,结合野外宏观巡查及勘查资料,研究了白家包滑坡的变形机理;基于改进切线角以及全自动监测数据定量化分析,获取滑坡等速变形速率和变形阶跃点,建立相应的预警模型.结果表明:白家包滑坡整体变形明显,滑坡变形主要集中于每年5—6月,滑坡累积曲线呈现典型的“阶跃”型的动态变形特性,受库水位升降作用影响表现出明显的“推拉效应”;库水位下降是白家包滑坡变形关键影响因素,且与库水位下降速率密切相关,在库水位快速下降期和低水位期,特大暴雨和持续降雨会促进变形;通过改进切线角方法及数据精细化分析,白家包滑坡的位移速率阈值为8.7 mm/d,库水阈值为库水位下降至149 m位移阶跃启动,最小下降速率为0.4 m/d.
Since the Three Gorges Reservoir was impounded in 2003,a large number of landslides in the reservoir area have been monitored and the cumulative displacement curve is step-shaped.Such landslides experience significant deformation under external influences within a certain period of time,and their mechanisms are too complex to make stability assessment and early warning.By studying the deformation characteristics and inducing factors,it is helpful to evaluate the stability of landslides and build appropriate early warning models.This paper takes the Baijiabao landslide as the research object,comprehensively analyzes 15 years of manual and 4 years of automatic GNSS surface displacement monitoring data,and combines field macroscopic inspection and survey data to study the deformation mechanism of Baijiabao landslide.Based on the improved tangent angle and automatic Quantitative analysis of monitoring data,the landslide's uniform deformation rate and deformation step point are obtained,and the corresponding warning model is established.The results show that:(1)The overall deformation of the Baijiabao landslide is obvious.The landslide deformation is mainly concentrated from May to June each year.The cumulative curve of the landslide presents a typical"step"type of dynamic deformation characteristics,and it shows an obvious push-pull effect due to the rise and fall of the reservoir water level.(2)The reservoir water level drop is the key driving factor for Baijiabao landslide deformation and is closely related to the reservoir water drop rate.During the operation period of the rapid decline of reservoir water level and low water level condition,heavy rain and continuous rainfall will promote deformation.(3)According to the tangent angle method and data refinement analysis,the threshold of displacement rate of Baijiabao landslide is 8.7 mm/d,the threshold of reservoir water is the step start of displacement when the reservoir water level drops to 149 m,with a minimum decrease rate of 0.4 m/d.
作者
王国法
邓茂林
周露露
董汉青
WANG Guofa;DENG Maolin;ZHOU Lulu;DONG Hanqing(College of Civil Engineering&Architecture,China Three Gorges Univ.,Yichang 443002,China;Hubei Key Laboratory of Disaster Prevention&Mitigation,China Three Gorges Univ.,Yichang 443002,China)
出处
《三峡大学学报（自然科学版）》
CAS
2023年第4期45-53,共9页
Journal of China Three Gorges University：Natural Sciences
基金
国家自然科学基金面上项目(42172303)。
关键词
白家包滑坡
位移阶跃
库水位
变形机理
预警模型
Baijiabao landslide
stepwise displacement
reservoir water level
deformation mechanism
early warning model
