缓倾角顺层岩质斜坡滑移-弯曲变形破坏的关键因子提取
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摘要
以缓倾角顺层岩质斜坡为研究对象,通过总结其发生滑移-弯曲变形破坏的工程地质特征,构建了该类斜坡的工程地质模型,在此基础上将斜坡岩层概化为长细杆件,利用压杆稳定理论推导了多层岩体发生弯曲的临界应力表达式,结果表明,斜坡稳定与岩层倾角、岩层厚度和滑体总厚度有关。将斜坡中的地下水效应分为浮托减重效应和静水压力效应,采用UDEC离散元软件模拟了2种效应在斜坡弯曲变形中的作用机理。结果表明,浮托减重效应主要影响坡面弯曲段5#、6#监测点的位移,而静水压力效应主要影响滑体底部8#、9#监测点的位移。最后,通过正交试验设计对岩层倾角、滑体厚度、岩层厚度及地下水位4个因素的重要性进行了排序。结果表明,无论是浮托减重效应还是静水压力效应,地下水重要性都排在前两位,表明水是决定缓倾角顺层岩质斜坡发生此类变形破坏的关键因素。
The paper is to propose an approach to identifying and determining the dominant factor responsible for the slip-buckling in the gently inclining bedding slope to sum up the engineering geological features from a few project samples.Furthermore,it is also hoped that the rock layer structure can be simplified as a slender bar to work out its bending critical stress by using Euler formula,for such a critical stress can mainly be related to the following 3 variables,that is,the rock layer dip angle,the sliding body thickness and the single layer thickness.In addition,the influence of the groundwater on the slope stability can also be generalized in the 2 kinds of typical mechanical effects,that is,the uplifting effect and the hydrostatic pressure one.Thus,to construct the bedding slope numerical model,it would be necessary to work out the total displacement degrees in the different effects by using a UDEC 2-D distinct element numerical software.And,next,the displacements of the 9 monitoring points can be used to compare the points to be analyzed with and without the groundwater as a key factor.The results indicate that the uplifting effect mainly influences the displacements of the monitoring points No.5 and No.6,which are situated on the slope surface,whereas the hydrostatic pressure effect mainly affects the displacements of the monitoring points No.8 and No.9,which are lying on the sliding surface.And,finally,the factors of the rock layer dip angle,the thickness of the sliding body,the thickness of the single layer and the groundwater itself can all be taken into consideration in the orthogonal testing target.Moreover,seeing that each factor should have 3 levels,it would be possible to build up the L9(34) orthogonal test while the groundwater as a key factor should be taken into as if it might consist of two different effects.The total displacement of No.6 and No.9 monitoring points can be respectively taken as the testing result analysis index for the uplifting effect and hydrostatic pressure effect.And,in terms of the order importance,it should be ranked by the displacement difference extents of the above mentioned 4 factors.The testing order should be arranged as the single layer thickness,the groundwater,the dip angle and the sliding body thickness from the beginning to the end in the uplifting effects.And it is the groundwater,the dip angle,the sliding body thickness and the single layer thickness that constitute the hydrostatic pressure effect.Therefore,no matter how the uplifting effect or hydrostatic pressure effect may be,the groundwater effect should always be relegated to the first two places among the said 4 factors.Thus,it should be acknowledged as the predominantly influential factor leading to the slip-buckling in the gently inclining bedding slope.
The paper is to propose an approach to identifying and determining the dominant factor responsible for the slip-buckling in the gently inclining bedding slope to sum up the engineering geological features from a few project samples.Furthermore,it is also hoped that the rock layer structure can be simplified as a slender bar to work out its bending critical stress by using Euler formula,for such a critical stress can mainly be related to the following 3 variables,that is,the rock layer dip angle,the sliding body thickness and the single layer thickness.In addition,the influence of the groundwater on the slope stability can also be generalized in the 2 kinds of typical mechanical effects,that is,the uplifting effect and the hydrostatic pressure one.Thus,to construct the bedding slope numerical model,it would be necessary to work out the total displacement degrees in the different effects by using a UDEC 2-D distinct element numerical software.And,next,the displacements of the 9 monitoring points can be used to compare the points to be analyzed with and without the groundwater as a key factor.The results indicate that the uplifting effect mainly influences the displacements of the monitoring points No.5 and No.6,which are situated on the slope surface,whereas the hydrostatic pressure effect mainly affects the displacements of the monitoring points No.8 and No.9,which are lying on the sliding surface.And,finally,the factors of the rock layer dip angle,the thickness of the sliding body,the thickness of the single layer and the groundwater itself can all be taken into consideration in the orthogonal testing target.Moreover,seeing that each factor should have 3 levels,it would be possible to build up the L9(34) orthogonal test while the groundwater as a key factor should be taken into as if it might consist of two different effects.The total displacement of No.6 and No.9 monitoring points can be respectively taken as the testing result analysis index for the uplifting effect and hydrostatic pressure effect.And,in terms of the order importance,it should be ranked by the displacement difference extents of the above mentioned 4 factors.The testing order should be arranged as the single layer thickness,the groundwater,the dip angle and the sliding body thickness from the beginning to the end in the uplifting effects.And it is the groundwater,the dip angle,the sliding body thickness and the single layer thickness that constitute the hydrostatic pressure effect.Therefore,no matter how the uplifting effect or hydrostatic pressure effect may be,the groundwater effect should always be relegated to the first two places among the said 4 factors.Thus,it should be acknowledged as the predominantly influential factor leading to the slip-buckling in the gently inclining bedding slope.
引文
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[12]LI Shusen(李树森),REN Guangming(任光明),ZUO Sansheng(左三胜).Mechanical analysis of instability mechanism of consequent slope in bedded rock mass[J].Journal of Geological Hazards and Environment Preservation(地质灾害与环境保护),1995,6(2):24-29.
[13]SUN Xunfang(孙训方),FANG Xiaoshu(方孝淑),GUAN Laitai(关来泰),et al.Mechanics of materials(材料力学)[M].4th ed.Beijing:Higher Education Press,2004.
[2]NUMADA M,KONAGAI K.Proposal of evaluation approach of slide surface friction coefficient of landslide that uses buckling theory[J].Seisan Kenkyu,2010,61(6):1021-1024.
[3]HE Qibiao(何启标).Research of stability of No.2 Landslide on front of Lijiaxia Hydropower Station Dam of Yellow River[J].Northwest Hydropower(西北水电),1992,1(4):1-6.
[4]ZHANG Zhuoyuan(张倬元),WANG Lansheng(王兰生),WANGShitian(王士天).Engineering geological analysis principle(工程地质分析原理)[M].Beijing:Geological Publishing House,1994.
[5]HU Yudao(胡余道).The development law and remediation practice of Tiexi Landslide[J].Railway Standard Design(铁道标准设计通讯),1987,1(1):14-21,13.
[6]LU Tao(鲁涛).Study of formation mechnism and later trend prediction of Fanjiaping Landslide and Baishuihe Landslide(范家坪、白水河滑坡形成机理及后期演化趋势预测)[D].Yichang:Three Gorges University,2012.
[7]MA Deqing(马德青),HU Huihua(胡惠华),ZHAO Jinju(赵金举).The mechianism analysis of Zhuque hole landslide in western Hunan[J].Journal of Hebei University of Engineering:Natural Science Edition(河北工程大学学报:自然科学版),2010,27(1):42-45.
[8]TANG Minggao(汤明高),MA Xu(马旭),ZHANG Tingting(张婷婷),et al.Early recognition and mechanism of creep-buckling of bedding slope[J].Journal of Engineering Geology(工程地质学报),2016,24(3):442-450.
[9]LIU Yunpeng(刘云鹏).Slip-bending mode instability mechanism and calculation methods comparison of slab-rent structure slope[J].Chinese Journal of Underground Space and Engineering(地下空间与工程学报),2017,13(S2):943-954.
[10]CHEN Mingdong(陈明东),WANG Lansheng(王兰生).Grey prediction analysis of Xintan Landslide[C]//Symposium on rock slope stability analysis and evaluation methods of the Chinese Geological Society(中国地质学会岩质边坡稳定性分析和评价方法讨论会).Monograph of Xintan Landslide Seminar(新滩滑坡讨论会文集).Chengdu:Chengdu University of Technology Press,1986:18.
[11]SUN Guangzhong(孙广忠).Rock mass structure mechanics(岩体结构力学)[M].Beijing:Science Press,1988.
[12]LI Shusen(李树森),REN Guangming(任光明),ZUO Sansheng(左三胜).Mechanical analysis of instability mechanism of consequent slope in bedded rock mass[J].Journal of Geological Hazards and Environment Preservation(地质灾害与环境保护),1995,6(2):24-29.
[13]SUN Xunfang(孙训方),FANG Xiaoshu(方孝淑),GUAN Laitai(关来泰),et al.Mechanics of materials(材料力学)[M].4th ed.Beijing:Higher Education Press,2004.