公路加宽高边坡二次开挖落石防护风险评估
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摘要
针对边坡在二次开挖扰动过程中的落石防护问题,基于京沪高速莱芜～临沂段路堑边坡改扩建工程,根据现场实际工况提出了开挖扰动作用下落石的两种运动方式,通过模拟人体步行运动及轨迹反算得到了两种施工扰动下落石的运动初始参数,采用Rocfall分析软件对开挖扰动下落石运动轨迹及落点进行了反演计算,依据落石拦截率这一指标对不同防护方案以及不同落石初始运动点位下防护结构安全性进行了评价,并通过现场观测对评价结果进行了验证。结果表明:(1)边坡机械破碎开挖引发溅石,运动距离较远,运动轨迹远离坡面不易拦截,对既有道路行车安全产生威胁;(2)防护结构对溅石的拦截率受机械开挖施工点位的影响较大,据此变化趋势提出了机械开挖的禁止区域及警戒区域;(3)由于人工扰动下落石经多次碰撞,运动轨迹逐渐远离坡面,运动方式由滚动转变为自由下落,故在边坡上部设置防护结构对落石的拦截效果较好。该研究成果及研究方法可为其他二次开挖边坡工程落石的风险评估、施工防护设计优化,提供参考。
Aiming at the protection of rockfall during the disturbance of secondary excavation,in this paper two movement modes of rockfall under excavation disturbance are proposed which is based on the reconstruction and expansion project of cut slope on the Laiwu to Linyi Section of the Beijing-Shanghai Expressway.The motion initial parameters of rockfall are acquired respectively by simulation of human walking and trajectory reverse calculation under two construction perturbations.The Rocfall analysis software is used to perform the inverse calculation for the rockfall path of the excavation undisturbed rock,and safety of protective structures under different protection schemes and different initial rockfall movement points is evaluated according to the rockfall interceptions rate.The evaluation results are verified by field observation.The results show that:(1)mechanical breaking and excavation of slope cause the movement distance of rocks further,which leads to intercept difficult and threat to existing road traffic safety.(2)The interception rate of splashing rock of protective structure is obviously affected by the construction site of mechanical excavation with forbidden area and warning area of mechanical excavation are put forward relying on this variation trend.(3)Due to the artificial disturbance,the track of the rockfall gradually moves away from the slope surface.The motion mode changes from rolling to falling.Therefore,the protective structure on the upper part of the slope has a better interception effect on rockfall.The research results and methods can provide references for risk assessment of rockfall and construction as well as optimization of protection design of other secondary excavation slope projects.
Aiming at the protection of rockfall during the disturbance of secondary excavation,in this paper two movement modes of rockfall under excavation disturbance are proposed which is based on the reconstruction and expansion project of cut slope on the Laiwu to Linyi Section of the Beijing-Shanghai Expressway.The motion initial parameters of rockfall are acquired respectively by simulation of human walking and trajectory reverse calculation under two construction perturbations.The Rocfall analysis software is used to perform the inverse calculation for the rockfall path of the excavation undisturbed rock,and safety of protective structures under different protection schemes and different initial rockfall movement points is evaluated according to the rockfall interceptions rate.The evaluation results are verified by field observation.The results show that:(1)mechanical breaking and excavation of slope cause the movement distance of rocks further,which leads to intercept difficult and threat to existing road traffic safety.(2)The interception rate of splashing rock of protective structure is obviously affected by the construction site of mechanical excavation with forbidden area and warning area of mechanical excavation are put forward relying on this variation trend.(3)Due to the artificial disturbance,the track of the rockfall gradually moves away from the slope surface.The motion mode changes from rolling to falling.Therefore,the protective structure on the upper part of the slope has a better interception effect on rockfall.The research results and methods can provide references for risk assessment of rockfall and construction as well as optimization of protection design of other secondary excavation slope projects.
引文
[1]Ashfield J R.The computer simulation and prediction of rock fall[D].Durham University,2001.
[2]Bozzolo D,Pamini R.Modello matematico per lo studio della caduta dei massi[M].Laboratorio di Fisica Terrestre-ICTS,Lugano-Trevano,1982.
[3]Bozzolo D,Pamini R.Simulation of Rock falls down a valley side[J].Acta Mech.1982,63:113-130.
[4]苏胜忠.边坡工程勘察中崩塌落石运动模式及轨迹分析[J].工程地质学报,2011,19(4):577-581.
[5]杨海清,周小平.边坡落石运动轨迹计算新方法[J].岩土力学,2009,30(11):3411-3416.
[6]吴顺川,高永涛,杨占峰.基于正交试验的露天矿高陡边坡落石随机预测[J].岩石力学与工程学报,2006,25(增1):2826-2832.
[7]黄润秋,刘卫华.基于正交设计的滚石运动特征现场试验研究[J].岩石力学与工程学报,2009,28(5):882-891.
[8]黄润秋,刘卫华,周江平,等.滚石运动特征试验研究[J].岩土工程学报,2007,29(9):1296-1302.
[9]周爱红,王帅伟,袁颖,等.岩质边坡落石运动特征分析及SVM预测模型[J].公路交通科技,2017,34(3):20-25.
[10]章广成,向欣,唐辉明.落石碰撞恢复系数的现场试验与数值计算[J].岩石力学与工程学报,2011,30(6):1266-1273.
[11]宋波,郝晓敏,黄帅.不同影响因子对落石运动距离影响的试验研究[J].四川大学学报:工程科学版,2016,48(6):1-7.
[12]宋波,李吉人,郝晓敏.边坡崩塌落石运动距离振动台试验研究[J].建筑结构学报,2016,37(增1):366-372.
[13]张青宇,唐世明,沈军辉.四川麻柳沟地震崩塌落石运动特征分析[J].人民长江,2015,46(13):39-41.
[14]叶四桥,陈洪凯,许江.落石运动模式与运动特征现场试验研究[J].土木建筑与环境工程,2011,33(2):18-23,44.
[15]叶四桥,巩尚卿,王林峰,等.落石碰撞切向恢复系数的取值研究[J].中国铁道科学,2018,39(1):8-15.
[16]刘丹,叶四桥,杨威,等.落石水平运动距离影响因素的模型试验研究[J].水文地质工程地质,2013,40(6):112-116.
[17]杨仲元.道路边坡危岩落石运动路径研究[J].公路交通科技,2010,27(1):34-38.
[18]刘永平,佴磊,李广杰,等.某高陡边坡崩塌落石运动特征分析及其防治[J].水文地质工程地质,2005,(1):30-33.
[19]Azzoni A,La Barbera G,Zaninetti A.Analysis and prediction of rockfalls using a mathematical model[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1995,32(7):709-724.
[20]K T Chau,R H C Wong,C F Lee.Rockfall Problem in Hong Kong and Some New Experimental Results for Coefficients of Restitution[J].International Journal of Rock Mechanics and Mining Sciences,1998,35(4/5):662-663.
[21]沈小辉,魏云杰,陶连金,等.斜坡危岩体崩塌运动的数学模型及工程应用[J].北京工业大学学报,2012,38(4):540-543.
[22]邹维勇,王金梅,王潘.落石运动路径按区间分段算法[J].防灾减灾工程学报,2017,37(1):79-84.
[23]叶四桥,巩尚卿.落石碰撞法向恢复系数的取值研究[J].中国铁道科学,2015,36(4):13-19.
[24]Giani G P,Giancomini A,Miglazza M,et al.Experimental and Theoretical Studies to Improve Rockfall Analysis and Protection Work Design[J].Rock Mechanics and Rock Engineering,2004,37(5):369-389.
[2]Bozzolo D,Pamini R.Modello matematico per lo studio della caduta dei massi[M].Laboratorio di Fisica Terrestre-ICTS,Lugano-Trevano,1982.
[3]Bozzolo D,Pamini R.Simulation of Rock falls down a valley side[J].Acta Mech.1982,63:113-130.
[4]苏胜忠.边坡工程勘察中崩塌落石运动模式及轨迹分析[J].工程地质学报,2011,19(4):577-581.
[5]杨海清,周小平.边坡落石运动轨迹计算新方法[J].岩土力学,2009,30(11):3411-3416.
[6]吴顺川,高永涛,杨占峰.基于正交试验的露天矿高陡边坡落石随机预测[J].岩石力学与工程学报,2006,25(增1):2826-2832.
[7]黄润秋,刘卫华.基于正交设计的滚石运动特征现场试验研究[J].岩石力学与工程学报,2009,28(5):882-891.
[8]黄润秋,刘卫华,周江平,等.滚石运动特征试验研究[J].岩土工程学报,2007,29(9):1296-1302.
[9]周爱红,王帅伟,袁颖,等.岩质边坡落石运动特征分析及SVM预测模型[J].公路交通科技,2017,34(3):20-25.
[10]章广成,向欣,唐辉明.落石碰撞恢复系数的现场试验与数值计算[J].岩石力学与工程学报,2011,30(6):1266-1273.
[11]宋波,郝晓敏,黄帅.不同影响因子对落石运动距离影响的试验研究[J].四川大学学报:工程科学版,2016,48(6):1-7.
[12]宋波,李吉人,郝晓敏.边坡崩塌落石运动距离振动台试验研究[J].建筑结构学报,2016,37(增1):366-372.
[13]张青宇,唐世明,沈军辉.四川麻柳沟地震崩塌落石运动特征分析[J].人民长江,2015,46(13):39-41.
[14]叶四桥,陈洪凯,许江.落石运动模式与运动特征现场试验研究[J].土木建筑与环境工程,2011,33(2):18-23,44.
[15]叶四桥,巩尚卿,王林峰,等.落石碰撞切向恢复系数的取值研究[J].中国铁道科学,2018,39(1):8-15.
[16]刘丹,叶四桥,杨威,等.落石水平运动距离影响因素的模型试验研究[J].水文地质工程地质,2013,40(6):112-116.
[17]杨仲元.道路边坡危岩落石运动路径研究[J].公路交通科技,2010,27(1):34-38.
[18]刘永平,佴磊,李广杰,等.某高陡边坡崩塌落石运动特征分析及其防治[J].水文地质工程地质,2005,(1):30-33.
[19]Azzoni A,La Barbera G,Zaninetti A.Analysis and prediction of rockfalls using a mathematical model[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1995,32(7):709-724.
[20]K T Chau,R H C Wong,C F Lee.Rockfall Problem in Hong Kong and Some New Experimental Results for Coefficients of Restitution[J].International Journal of Rock Mechanics and Mining Sciences,1998,35(4/5):662-663.
[21]沈小辉,魏云杰,陶连金,等.斜坡危岩体崩塌运动的数学模型及工程应用[J].北京工业大学学报,2012,38(4):540-543.
[22]邹维勇,王金梅,王潘.落石运动路径按区间分段算法[J].防灾减灾工程学报,2017,37(1):79-84.
[23]叶四桥,巩尚卿.落石碰撞法向恢复系数的取值研究[J].中国铁道科学,2015,36(4):13-19.
[24]Giani G P,Giancomini A,Miglazza M,et al.Experimental and Theoretical Studies to Improve Rockfall Analysis and Protection Work Design[J].Rock Mechanics and Rock Engineering,2004,37(5):369-389.