三峡库区藕塘滑坡变形特点及复活机制研究
|
摘要
为深入研究库区古滑坡变形特征及其复活机理,文章以三峡库区藕塘滑坡为研究对象,通过对钻孔、探槽及平硐等现场勘查资料和监测资料的深入分析,并结合数值模拟方法,探讨了藕塘滑坡的时-空变形特点及影响因素,并揭示其复活机制。电子自旋共振试验和现场勘查结果表明藕塘滑坡由三个次级滑体组成。监测数据显示:总体上,地表累计位移-时间曲线呈阶跃状变化,即雨季滑坡变形速率急剧加快,旱季则骤减;在空间上滑坡的变形速率随高程的增加而增加。库水和降雨是导致藕塘滑坡变形破坏的主要因素:滑坡下部区域变形主要受库水影响,而滑坡中、上部区域变形主要受降雨影响。数值模拟结果也进一步揭示了影响滑坡孔隙水压力响应的主控因素随滑坡高程的变化而变化。库水骤降使得坡体前部渗透压增大,同时强降雨使得坡体中部及上部孔隙水压力升高,二者共同作用下导致滑坡复活。此外库水位下降或降雨量增加,均会不同程度降低边坡的稳定性。以上结论对于指导实际工程及深化库区古滑坡的研究具有一定的理论意义,同时加强古滑坡的研究有助于丰富滑坡稳定性评价及预测预报方法,为古滑坡的治理提供一定的理论依据。
To study the deformation characteristics and the triggering-mechanism of ancient landslide,the Outang landslide is selected as a research object and its temporal-spatial deformation characteristics,corresponding trigger factors and reactivated mechanism are examined based on detailed analyses of geological materials obtained by using boreholes,trench,adits and monitoring data sets as well as the simulation numerical model. Electron spin resonance tests and in-site investigations show that the Outang landslide is composed by three secondary sliding masses. Generally,the cumulative displacement-time curves are stepshaped,characterized by rapid displacement in the summer followed by almost imperceptible movement at dry seasons. The displacement velocities usually increase spatially with the rise of elevation. The deformation of the Outang landslide is primarily controlled by reservoir water and rainfall. The deformation of the lower part of the landslide is mainly affected by reservoir water,while the deformation of the middle and upper part of the landslide is mainly affected by rainfall. Numerical analyses further reveals that the main controlling factors influencing the pore water pressure of landslide vary with the change of the elevation. The coupled actions of increased in seepage pressure at the front and the pore water pressure at the middle and upper parts result in the reactivation of the Outang landslide. In addition,the slope stability will be reduced to different degrees when the water level of the reservoir decreases or the rainfall increases. The results are very useful not only in the practical engineering but also in the theoretical study of the ancient landslide in reservoir areas. Moreover,strengthening the study of old landslide would enrich the methods on landslide forecast and its stability evaluation,and provide the guideline of ancient landslide prevention.
To study the deformation characteristics and the triggering-mechanism of ancient landslide,the Outang landslide is selected as a research object and its temporal-spatial deformation characteristics,corresponding trigger factors and reactivated mechanism are examined based on detailed analyses of geological materials obtained by using boreholes,trench,adits and monitoring data sets as well as the simulation numerical model. Electron spin resonance tests and in-site investigations show that the Outang landslide is composed by three secondary sliding masses. Generally,the cumulative displacement-time curves are stepshaped,characterized by rapid displacement in the summer followed by almost imperceptible movement at dry seasons. The displacement velocities usually increase spatially with the rise of elevation. The deformation of the Outang landslide is primarily controlled by reservoir water and rainfall. The deformation of the lower part of the landslide is mainly affected by reservoir water,while the deformation of the middle and upper part of the landslide is mainly affected by rainfall. Numerical analyses further reveals that the main controlling factors influencing the pore water pressure of landslide vary with the change of the elevation. The coupled actions of increased in seepage pressure at the front and the pore water pressure at the middle and upper parts result in the reactivation of the Outang landslide. In addition,the slope stability will be reduced to different degrees when the water level of the reservoir decreases or the rainfall increases. The results are very useful not only in the practical engineering but also in the theoretical study of the ancient landslide in reservoir areas. Moreover,strengthening the study of old landslide would enrich the methods on landslide forecast and its stability evaluation,and provide the guideline of ancient landslide prevention.
引文
[1]傅鹏辉.库水位下降条件下滑坡稳定性及动力增载位移响应规律研究———以三峡库区典型堆积层滑坡为例[D].青岛:青岛理工大学,2018.[FU P H.The displacement response ratio of dynamic increment of landslide under the condition of reservoir water level drop:Taking typical debris landslide in Three Gorges Reservoir area as an example[D]. Qingdao:Qingdao University of Technology,2018.(in Chinese)]
[2]闵弘,谭国焕,戴福初,等.蓄水期库岸古滑坡的水动力学响应监测———以三峡库区泄滩滑坡为例[J].岩石力学与工程学报,2004,23(21):3721-3726.[MIN H,TAN G H,DAI F C,et al.Hydrodynamic monitoring of a preexisting landslide during reservoir filling-acase history of Xietan landslide,the Three Gorges Reservoir[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(21):3721-3726.(in Chinese)]
[3]简文星,许强,童龙云,等.三峡库区黄土坡滑坡降雨入渗模型研究[J].岩土力学,2013,34(12):3527-3533.[JIAN W X,XU Q,TONG Y L,et al. Rainfall infiltration model of Huangtupo landslide in Three Gorges Reservoir area[J]. Rock and Soil Mechanics,2013,34(12):3527-3533.(in Chinese)]
[4]张开鹏,刘新喜.降雨入渗对三峡库区堆积层滑坡稳定性的影响[J]中国安全科学学报,2006,16(6):4-8.[ZHANG K P,LIU X X. Effects of rainfall infiltration landslide stability of accumulation horizon at Three Gorges Reservoir area[J]. China Safety Science Journal,2006,16(6):4-8.(in Chinese)]
[5] JIAN W,WANG Z,YIN K. Mechanism of the Anlesi landslide in the Three Gorges Reservoir,China[J].Engineering Geology,2009,108(1/2):86-95.
[6]缪海波,殷坤龙,李远耀,等.近水平地层滑坡平面失稳模型与破坏判据研究[J].水文地质工程地质,2009,36(1):69-74.[MIAO H B,YIN K L,LI Y Y, et al. Study on plane instability model and failure criterion of horizontal-strata landslide[J].Hydrogeology&Engineering Geology,2009,36(1):69-74.(in Chinese)]
[7]简文星,殷坤龙,罗冲,等.三峡库区万州安乐寺滑坡滑带特征[J].地球科学:中国地质大学学报,2008,33(5):672-678.[JIAN W X,YIN K L,LUO C,et al. Slip zone characteristics of Anlesi Landslide in Wanzhou of Three Gorges Reservoir Area[J]. Earth Science:Journal of China University of Geosciences,2008,33(5):672-678.(in Chinese)]
[8] TANG H,LI C,HU X,et al. Evolution characteristics of the Huangtupo landslide based on in situ tunneling and monitoring[J]. Landslides,2015,12(3):511-521.
[9]刘清秉,王顺,夏冬生,等.残余强度状态下原状滑带土蠕变特性试验研究[J].岩土力学,2017,38(5):1305-1313.[LIU Q B,WANG S,XIA D S,et al.Experimental study of residual-state creep behavior of intact sliding-zone soil[J]. Rock and Soil Mechanics,2017,38(5):1305-1313.(in Chinese)]
[10] GU D M, HUANG D, YANG W D, et al.Understanding the triggering mechanism and possible kinematic evolution of a reactivated landslide in the Three Gorges Reservoir[J]. Landslides,2017(10):1-15.
[11] HUANG D,GU D M,SONG Y X,et al. Towards a complete understanding of the triggering mechanism of a large reactivated landslide in the Three Gorges Reservoir[J]. Engineering Geology,2018,238:36-51.
[12] YIN Y P,HUANG B,WANG W P,et al. Reservoirinduced landslides and risk control in Three Gorges Project on Yangtze River,China[J]. Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):577-595.
[13]代贞伟,殷跃平,魏云杰,等.三峡库区藕塘滑坡特征、成因及形成机制研究[J].水文地质工程地质,2015,42(6):145-153.[DAI Z W,YIN Y P,WEI Y J,et al. Characteristics,origin and formation mechanism of the Outang landslide in the Three Gorges Reservoir area[J]. Hydrogeology&Engineering Geology,2015,42(6):145-153.(in Chinese)]
[14]胡致远,王伟,罗贤敏.库水与降雨联合作用下藕塘滑坡稳定性研究[J].人民黄河,2017,39(7):151-155.[HU Z Y,WANG W,LUO X M,et al.Study on the landslide stability of Outang under the combined action of reservoir water level fluctuation and rainfall[J]. Yellow River,2017,39(7):151-155.(in Chinese)]
[15]肖婷,殷坤龙.杨背背.三峡库区四方碑滑坡稳定性与变形趋势预测[J].中国地质灾害与防治学报,2018,29(1):10-14.[XIAO T,YIN K L,YANG B B. Stability and deformation trend prediction of the Sifangbei landslide in the Three Gorges Reservoir[J]. The Chinese Journal of Geological Hazard and Control,2018,29(1):10-14.(in Chinese)]
[16]周云涛,陈洪凯,张勇,等.超孔隙水压诱发特大型近水平崩坡积层滑坡破坏研究[J].工程地质学报,2016,24(5):732-740.[ZHOU Y T,CHEN H K,ZHANG Y,et al. Failure of super-huge landslide in collapsed debris deposits wish nearly horizontal sliding supface induced by excess pore pressure[J]. Journal of Engineering Geology,2016,24(5):732-740.(in Chinese)]
[17]曾耀.水库库岸老滑坡复活过程中地下水作用机制研究[D].武汉:中国地质大学(武汉),2010.[ZENG Y. Research on the mechanism of ground water in reactivating of old landslides on reservoir bank[D]. Wuhan:China University of Geosciences(Wuhan),2010.(in Chinese)]
[18]代贞伟,殷跃平,魏云杰,等.三峡库区藕塘滑坡变形失稳机制研究[J].工程地质学报,2016,24(1):44-55.[DAI Z W,YIN Y P,WEI Y J,et al.Deformation and failure mechanism of Outang landslide in Three Gorgers Reservoir area[J]. Journal of Engineering Geology,2016,24(1):44-55.(in Chinese)]
[19]黄达,顾东明,陈智强,等.三峡库区塔坪H2古滑坡台阶状复活变形的库水-降雨耦合作用机制[J].岩土工程学报,2017,39(12):2203-2211.[HUANG D,GU D M,CHEN Z Q,et al. Hybrid effects of rainfall and reservoir level fluctuation on the old Taping H2 landslide in the Wushang County,Three Gorges Reservoir[J]. Chinese Journal of Geotechnical Engineering,2017,39(12):2203-2211.(in Chinese)]
[2]闵弘,谭国焕,戴福初,等.蓄水期库岸古滑坡的水动力学响应监测———以三峡库区泄滩滑坡为例[J].岩石力学与工程学报,2004,23(21):3721-3726.[MIN H,TAN G H,DAI F C,et al.Hydrodynamic monitoring of a preexisting landslide during reservoir filling-acase history of Xietan landslide,the Three Gorges Reservoir[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(21):3721-3726.(in Chinese)]
[3]简文星,许强,童龙云,等.三峡库区黄土坡滑坡降雨入渗模型研究[J].岩土力学,2013,34(12):3527-3533.[JIAN W X,XU Q,TONG Y L,et al. Rainfall infiltration model of Huangtupo landslide in Three Gorges Reservoir area[J]. Rock and Soil Mechanics,2013,34(12):3527-3533.(in Chinese)]
[4]张开鹏,刘新喜.降雨入渗对三峡库区堆积层滑坡稳定性的影响[J]中国安全科学学报,2006,16(6):4-8.[ZHANG K P,LIU X X. Effects of rainfall infiltration landslide stability of accumulation horizon at Three Gorges Reservoir area[J]. China Safety Science Journal,2006,16(6):4-8.(in Chinese)]
[5] JIAN W,WANG Z,YIN K. Mechanism of the Anlesi landslide in the Three Gorges Reservoir,China[J].Engineering Geology,2009,108(1/2):86-95.
[6]缪海波,殷坤龙,李远耀,等.近水平地层滑坡平面失稳模型与破坏判据研究[J].水文地质工程地质,2009,36(1):69-74.[MIAO H B,YIN K L,LI Y Y, et al. Study on plane instability model and failure criterion of horizontal-strata landslide[J].Hydrogeology&Engineering Geology,2009,36(1):69-74.(in Chinese)]
[7]简文星,殷坤龙,罗冲,等.三峡库区万州安乐寺滑坡滑带特征[J].地球科学:中国地质大学学报,2008,33(5):672-678.[JIAN W X,YIN K L,LUO C,et al. Slip zone characteristics of Anlesi Landslide in Wanzhou of Three Gorges Reservoir Area[J]. Earth Science:Journal of China University of Geosciences,2008,33(5):672-678.(in Chinese)]
[8] TANG H,LI C,HU X,et al. Evolution characteristics of the Huangtupo landslide based on in situ tunneling and monitoring[J]. Landslides,2015,12(3):511-521.
[9]刘清秉,王顺,夏冬生,等.残余强度状态下原状滑带土蠕变特性试验研究[J].岩土力学,2017,38(5):1305-1313.[LIU Q B,WANG S,XIA D S,et al.Experimental study of residual-state creep behavior of intact sliding-zone soil[J]. Rock and Soil Mechanics,2017,38(5):1305-1313.(in Chinese)]
[10] GU D M, HUANG D, YANG W D, et al.Understanding the triggering mechanism and possible kinematic evolution of a reactivated landslide in the Three Gorges Reservoir[J]. Landslides,2017(10):1-15.
[11] HUANG D,GU D M,SONG Y X,et al. Towards a complete understanding of the triggering mechanism of a large reactivated landslide in the Three Gorges Reservoir[J]. Engineering Geology,2018,238:36-51.
[12] YIN Y P,HUANG B,WANG W P,et al. Reservoirinduced landslides and risk control in Three Gorges Project on Yangtze River,China[J]. Journal of Rock Mechanics and Geotechnical Engineering,2016,8(5):577-595.
[13]代贞伟,殷跃平,魏云杰,等.三峡库区藕塘滑坡特征、成因及形成机制研究[J].水文地质工程地质,2015,42(6):145-153.[DAI Z W,YIN Y P,WEI Y J,et al. Characteristics,origin and formation mechanism of the Outang landslide in the Three Gorges Reservoir area[J]. Hydrogeology&Engineering Geology,2015,42(6):145-153.(in Chinese)]
[14]胡致远,王伟,罗贤敏.库水与降雨联合作用下藕塘滑坡稳定性研究[J].人民黄河,2017,39(7):151-155.[HU Z Y,WANG W,LUO X M,et al.Study on the landslide stability of Outang under the combined action of reservoir water level fluctuation and rainfall[J]. Yellow River,2017,39(7):151-155.(in Chinese)]
[15]肖婷,殷坤龙.杨背背.三峡库区四方碑滑坡稳定性与变形趋势预测[J].中国地质灾害与防治学报,2018,29(1):10-14.[XIAO T,YIN K L,YANG B B. Stability and deformation trend prediction of the Sifangbei landslide in the Three Gorges Reservoir[J]. The Chinese Journal of Geological Hazard and Control,2018,29(1):10-14.(in Chinese)]
[16]周云涛,陈洪凯,张勇,等.超孔隙水压诱发特大型近水平崩坡积层滑坡破坏研究[J].工程地质学报,2016,24(5):732-740.[ZHOU Y T,CHEN H K,ZHANG Y,et al. Failure of super-huge landslide in collapsed debris deposits wish nearly horizontal sliding supface induced by excess pore pressure[J]. Journal of Engineering Geology,2016,24(5):732-740.(in Chinese)]
[17]曾耀.水库库岸老滑坡复活过程中地下水作用机制研究[D].武汉:中国地质大学(武汉),2010.[ZENG Y. Research on the mechanism of ground water in reactivating of old landslides on reservoir bank[D]. Wuhan:China University of Geosciences(Wuhan),2010.(in Chinese)]
[18]代贞伟,殷跃平,魏云杰,等.三峡库区藕塘滑坡变形失稳机制研究[J].工程地质学报,2016,24(1):44-55.[DAI Z W,YIN Y P,WEI Y J,et al.Deformation and failure mechanism of Outang landslide in Three Gorgers Reservoir area[J]. Journal of Engineering Geology,2016,24(1):44-55.(in Chinese)]
[19]黄达,顾东明,陈智强,等.三峡库区塔坪H2古滑坡台阶状复活变形的库水-降雨耦合作用机制[J].岩土工程学报,2017,39(12):2203-2211.[HUANG D,GU D M,CHEN Z Q,et al. Hybrid effects of rainfall and reservoir level fluctuation on the old Taping H2 landslide in the Wushang County,Three Gorges Reservoir[J]. Chinese Journal of Geotechnical Engineering,2017,39(12):2203-2211.(in Chinese)]
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |