基于PhotoInfor的边坡开挖效应模型试验
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摘要
为了研究开挖效应对残积土坡坡体内部变形特征及边坡失稳机理的影响,以福宁(福鼎—宁德)高速公路某高路堑边坡为原型,依据相似理论设计地质力学模型所需相似材料及其合理配比,结合自制监测系统和数字照相量测技术,开展基于PhotoInfor的多级边坡开挖效应模型试验研究,分析多级开挖过程中模型边坡坡体位移及应力的变化规律。研究结果表明:开挖过程中边坡坡体变形是由缓慢至加速滑动的渐进过程,坡体中部和坡脚开挖时,坡体内部位移增长速率最快;坡体上部位移大于下部土体位移,且从坡体内部向临空面方向位移逐渐增大;边坡在开挖过程中坡体内部土体应力分布不均,坡脚处应力集中度高,边坡前端推力随着开挖过程逐渐增大;开挖卸载效应打破了边坡原有应力平衡,坡体后缘出现张拉裂隙,裂隙在整个开挖过程中不断发育、扩展和连通,形成贯通裂缝及滑动带,滑动带的形成过程与应力集中→释放→转移→重新调整造成的局部应变集中现象一致;开挖效应具有一定时效性,应力与位移变化并不同步,应变集中具有一定的滞后性,对此类边坡的早期监测,应以水平位移增长速率为控制指标,后期监测应兼顾水平位移和应力水平增长速率,两者缺一不可。该研究成果可为中国东南沿海地区多级边坡开挖的预警监测和支护加固提供重要依据。
The effects of deformation characteristics and slope instability mechanism on residual soil slope under the excavation effect were investigated, by using a high cutting slope of the Funing(Fuding to Ningde) Expressway as a sample, a geo-mechanical model using similar materials according to the similarity theory, was designed. A model test study was conducted, using a real-time monitoring system and digital photogrammetry technology on the multi-stage slope excavation effect based on PhotoInfor, and changes of displacement and stress during multi-stage excavation of model slope were analyzed. The results show that the variation in the excavated slope is a gradual process from slow deformation to accelerated sliding, the rate of displacement increases the fastest in the slope under the slope excavation at the middle and top positions, the soil displacement at the slope top position is greater than that at the lower part, and the displacement from the slope inside to the hollow face increases gradually. Further, soil stress-distribution is not uniform in the slope excavation process, the stress concentration at the foot of slope is higher, and the thrust at the front end of slope accelerates gradually during the excavation process. The original stress balance of the slope is disturbed when the excavation. A tension crack formed in the rear edge of the slope and then the crack developed, expanded, and connected continuously during the whole excavation process. Then, the crack formed through the fracture and sliding zone. The forming process of the slip zone is consistent with that of the local strain concentration caused by stress concentration, release, transfer and re-adjustment. Meanwhile, the excavation effect possesses a certain time-effect, the stress and displacement change are not synchronized, and the strain concentration shows a certain hysteresis, therefore, the early monitoring of this kind of slope should be considered to choose the control index of the horizontal displacement growth rate. The stress horizontal growth rate should be consider in the post monitoring, both growth rates are indispensable. The research results provide an important basis for early warning monitoring and support reinforcement of excavated slope in the southeast coastal area of China. 3 tabs, 12 figs, 25 refs.
The effects of deformation characteristics and slope instability mechanism on residual soil slope under the excavation effect were investigated, by using a high cutting slope of the Funing(Fuding to Ningde) Expressway as a sample, a geo-mechanical model using similar materials according to the similarity theory, was designed. A model test study was conducted, using a real-time monitoring system and digital photogrammetry technology on the multi-stage slope excavation effect based on PhotoInfor, and changes of displacement and stress during multi-stage excavation of model slope were analyzed. The results show that the variation in the excavated slope is a gradual process from slow deformation to accelerated sliding, the rate of displacement increases the fastest in the slope under the slope excavation at the middle and top positions, the soil displacement at the slope top position is greater than that at the lower part, and the displacement from the slope inside to the hollow face increases gradually. Further, soil stress-distribution is not uniform in the slope excavation process, the stress concentration at the foot of slope is higher, and the thrust at the front end of slope accelerates gradually during the excavation process. The original stress balance of the slope is disturbed when the excavation. A tension crack formed in the rear edge of the slope and then the crack developed, expanded, and connected continuously during the whole excavation process. Then, the crack formed through the fracture and sliding zone. The forming process of the slip zone is consistent with that of the local strain concentration caused by stress concentration, release, transfer and re-adjustment. Meanwhile, the excavation effect possesses a certain time-effect, the stress and displacement change are not synchronized, and the strain concentration shows a certain hysteresis, therefore, the early monitoring of this kind of slope should be considered to choose the control index of the horizontal displacement growth rate. The stress horizontal growth rate should be consider in the post monitoring, both growth rates are indispensable. The research results provide an important basis for early warning monitoring and support reinforcement of excavated slope in the southeast coastal area of China. 3 tabs, 12 figs, 25 refs.
引文
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[15] 许旭堂,简文彬,吴能森.反复吸湿循环对原状残积土剪切特性的影响[J].中国公路学报,2017,30(2):33-40.XU Xu-tang,JIAN Wen-bin,WU Neng-sen.Influence of repeated wetting cycles on shear properties of natural residual soil[J].China Journal of Highway and Transport,2017,30(2):33-40.
[16] 陈祖煜,蔡云鹏,王玉杰,等.边坡倾倒稳定分析Goodman-Bray法:改进、测试与应用[J].中国公路学报,2018,31(2):30-38.CHEN Zu-yu,CAI Yun-peng,WANG Yu-jie,et al.Improvement,testing and application on Goodman-Bray method for stability analysis of toppling slope[J].China Journal of Highway and Transport,2018,31(2):30-38.
[17] TU X B,KWONG A K L,DAI F C,et al.Field monitoring of rainfall infiltration in a loess slope and analysis of failure mechanism of rainfall-induced landslides[J].Engineering Geology,2009,105(1/2):134-150.
[18] TAKEMURA J,KONDOH M,ESAKI T,et al.Centrifuge model tests on double propped wall excavation in soft clay[J].Soils and Foundations,1999,39(3):75-87.
[19] 罗先启,葛修润.滑坡模型试验理论及其应用[M].北京:中国水利水电出版社,2008.LUO Xian-qi,GE Xiu-run.Theory and application of model test on landslide[M].Beijing:China Water and Power Press,2008.
[20] 李元海,靖洪文,刘刚,等.数字照相量测在岩石隧道模型试验中的应用研究[J].岩石力学与工程学报,2007,26(8):1684-1690.LI Yuan-hai,JING Hong-wen,LIU Gang,et al.Study on application of digital close range photogrammetry to model test of tunnerl in jointed rock masses[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(8):1684-1690.
[21] 李元海,林志斌,靖洪文,等.含动态裂隙岩体的高精度数字散斑相关量测方法[J].岩土工程学报,2012,34(6):1060-1068.LI Yuan-hai,LIN Zhi-bin,JING Hong-wen,et al.High-accuracy digital speckle correlation method for rock with dynamic fractures[J].Chinese Journal of Geotechnical Engineering,2012,34(6):1060-1068.
[22] 李元海,靖洪文,曾庆有.岩土工程数字照相量测软件系统研发与应用[J].岩石力学与工程学报,2006,25(增2):3859-3866.LI Yuan-hai,JING Hong-wen,ZENG Qing-you.Development and application of digital photogrammetry software package for geotechnical engineering[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(S2):3859-3866.
[23] 许薛军,张肖宁.基于双目视觉的公路边坡表面位移识别方法[J].中国公路学报,2015,28(4):27-34.XU Xue-jun,ZHANG Xiao-ning.Highway slope displacement identification method based on binocular vision[J].China Journal of Highway and Transport,2015,28(4):27-34.
[24] 陈玮,简文彬,董岩松,等.软弱结构面对花岗岩残积土边坡稳定性影响[J].中国地质灾害与防治学报,2015,26(1):23-30.CHEN Wei,JIAN Wen-bin,DONG Yan-song,et al.Influence of weak structural surface on stability of granite residual soil slopes[J].Chinese Journal of Geological Hazard and Control,2015,26(1):23-30.
[25] 许旭堂,简文彬,吴能森,等.降雨诱发残积土坡失稳的模型试验[J].中国公路学报,2018,31(2):270-279.XU Xu-tang,JIAN Wen-bin,WU Neng-sen,et al.Model test of rainfall-induced residual soil slope failure[J].China Journal of Highway and Transport,2018,31(2):270-279.
[2] XU L,DAI F,CHEN J,et al.Analysis of a progressive slope failure in the Xiangjiaba reservoir area,Southwest China[J].Landslides,2014,11(1):55-66.
[3] WANG J J,LIANG Y,ZHANG H P,et al.A loess landslide induced by excavation and rainfall[J].Landslides,2014,11(1):141-152.
[4] ZHANG X,TANG Z Y.Slope excavation and parameter sensitivity analysis based on grey correlation method[J].Electronic Journal of Geotechnical Engineering,2016,21:4549-4558.
[5] LI Z Q,OYEDIRAN I A,TANG C,et al.FEM application to loess slope excavation and support:Case study of Dong Loutian coal bunker,Shuozhou,China[J].Bulletin of Engineering Geology and the Environment,2014,73(4):1013-1023.
[6] 林素明,李建福.路堑边坡施工过程中后缘变形演化分析[J].土工基础,2014,28(6):99-102.LIN Su-ming,LI Jian-fu.Deformation at the crest of highway cut slopes[J].Soil Engineering and Foundation,2014,28(6):99-102.
[7] 唐芬,郑颖人,赵尚毅.土坡渐进破坏的双安全系数讨论[J].岩石力学与工程学报,2007,26(7):1402-1407.TANG Fen,ZHENG Ying-ren,ZHAO Shang-yi.Discussion on two safety factors for progressive failure of the soil slope[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(7):1402-1407.
[8] 陈国庆,黄润秋,周辉,等.边坡渐进破坏的动态强度折减法研究[J].岩土力学,2013,34(4):1140-1146.CHEN Guo-qing,HUANG Run-qiu,ZHOU Hui,et al.Research on progressive failure for slope using dynamic strength reduction method[J].Rock and Soil Mechanics,2013,34(4):1140-1146.
[9] 张振华,冯夏庭,周辉,等.基于设计安全系数及破坏模式的边坡开挖过程动态变形监测预警方法研究[J].岩土力学,2009,30(3):603-612.ZHANG Zhen-hua,FENG Xia-ting,ZHOU Hui,et al.Research on dynamic early warning method of slope deformation monitoring during excavation based on designed safety factor and failure mode[J].Rock and Soil Mechanics,2009,30(3):603-612.
[10] JI Zhao-hong.Stability of soil cutting and side slope based on stress route theory[J].Urban Transportation & Construction,2015,1(2):1-4.
[11] ANBAZHAGAN S,RAMESH V,SARANAATHAN S E.Cut slope stability assessment along ghat road section of Kolli hills,India[J].Natural Hazards,2017,86(3):1081-1104.
[12] STANIER S A,WHITE D J.Improved image-based deformation measurement in the centrifuge environment[J].Geotechnical Testing Journal,2013,36(6):915-928.
[13] 高喜才.露天矿边坡开挖过程变形破坏特征及稳定性实验研究[D].西安:西安科技大学,2006.GAO Xi-cai.Experimental research on stability and dynamic displacement characters due to slope excavation in open-pit mine[D].Xi'an:Xi'an University of Science and Technology,2006.
[14] FAN Z,KULATILAKE P,PENG J,et al.In-flight excavation of a loess slope in a centrifuge model test[J].Geotechnical and Geological Engineering,2016,34(5):1577-1591.
[15] 许旭堂,简文彬,吴能森.反复吸湿循环对原状残积土剪切特性的影响[J].中国公路学报,2017,30(2):33-40.XU Xu-tang,JIAN Wen-bin,WU Neng-sen.Influence of repeated wetting cycles on shear properties of natural residual soil[J].China Journal of Highway and Transport,2017,30(2):33-40.
[16] 陈祖煜,蔡云鹏,王玉杰,等.边坡倾倒稳定分析Goodman-Bray法:改进、测试与应用[J].中国公路学报,2018,31(2):30-38.CHEN Zu-yu,CAI Yun-peng,WANG Yu-jie,et al.Improvement,testing and application on Goodman-Bray method for stability analysis of toppling slope[J].China Journal of Highway and Transport,2018,31(2):30-38.
[17] TU X B,KWONG A K L,DAI F C,et al.Field monitoring of rainfall infiltration in a loess slope and analysis of failure mechanism of rainfall-induced landslides[J].Engineering Geology,2009,105(1/2):134-150.
[18] TAKEMURA J,KONDOH M,ESAKI T,et al.Centrifuge model tests on double propped wall excavation in soft clay[J].Soils and Foundations,1999,39(3):75-87.
[19] 罗先启,葛修润.滑坡模型试验理论及其应用[M].北京:中国水利水电出版社,2008.LUO Xian-qi,GE Xiu-run.Theory and application of model test on landslide[M].Beijing:China Water and Power Press,2008.
[20] 李元海,靖洪文,刘刚,等.数字照相量测在岩石隧道模型试验中的应用研究[J].岩石力学与工程学报,2007,26(8):1684-1690.LI Yuan-hai,JING Hong-wen,LIU Gang,et al.Study on application of digital close range photogrammetry to model test of tunnerl in jointed rock masses[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(8):1684-1690.
[21] 李元海,林志斌,靖洪文,等.含动态裂隙岩体的高精度数字散斑相关量测方法[J].岩土工程学报,2012,34(6):1060-1068.LI Yuan-hai,LIN Zhi-bin,JING Hong-wen,et al.High-accuracy digital speckle correlation method for rock with dynamic fractures[J].Chinese Journal of Geotechnical Engineering,2012,34(6):1060-1068.
[22] 李元海,靖洪文,曾庆有.岩土工程数字照相量测软件系统研发与应用[J].岩石力学与工程学报,2006,25(增2):3859-3866.LI Yuan-hai,JING Hong-wen,ZENG Qing-you.Development and application of digital photogrammetry software package for geotechnical engineering[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(S2):3859-3866.
[23] 许薛军,张肖宁.基于双目视觉的公路边坡表面位移识别方法[J].中国公路学报,2015,28(4):27-34.XU Xue-jun,ZHANG Xiao-ning.Highway slope displacement identification method based on binocular vision[J].China Journal of Highway and Transport,2015,28(4):27-34.
[24] 陈玮,简文彬,董岩松,等.软弱结构面对花岗岩残积土边坡稳定性影响[J].中国地质灾害与防治学报,2015,26(1):23-30.CHEN Wei,JIAN Wen-bin,DONG Yan-song,et al.Influence of weak structural surface on stability of granite residual soil slopes[J].Chinese Journal of Geological Hazard and Control,2015,26(1):23-30.
[25] 许旭堂,简文彬,吴能森,等.降雨诱发残积土坡失稳的模型试验[J].中国公路学报,2018,31(2):270-279.XU Xu-tang,JIAN Wen-bin,WU Neng-sen,et al.Model test of rainfall-induced residual soil slope failure[J].China Journal of Highway and Transport,2018,31(2):270-279.