西安建筑科技大学学报(自然科学版)

针对陕北某高填方工程典型黄土Q2、Q3的抗剪强度指标分布概率模型及变异性进行了统计分析,并将结果应用于黄土自然高边坡和填方边坡可靠度分析中.对比了可靠度分析与有限元分析的边坡稳定性计算结果,并初步探讨了基于可靠度分析法的黄土填方边坡坡率优化办法.研究结果表明:Q2和Q3的c、φ值均接受正态分布和对数正态分布,且c值的变异性较大,φ值的变异性较小; φ值变异性对黄土自然边坡的可靠性指数影响程度普遍大于c值; 相对应地,对于填方边坡而言c值变异性的影响更大,这可能与土体颗粒得重新排列与结构重新分布有关; 通过方法的对比分析,验证了可靠度分析方法的准确性与适用性,在缺乏模型试验及监测数据的支撑下,可用于黄土边坡的可靠度分析及坡率优化; 若要求填方边坡失效概率小于10%,则坡高与最小坡度系数的关系式为y=0.008 2x+1.422.

The distribution probability model and variability of shear strength index of typical loess Q2 and Q3 in a high fill project in northern Shaanxi were statistically analyzed, and the results were applied to the reliability analysis of natural high loess slope and backfill slope. The slope stability calculation results of reliability analysis and finite element analysis were compared, and the optimization method of loess backfill slope ratio was preliminarily discussed based on reliability analysis. The results show that both normal and lognormal distribution is capable of describing the mechanical behavior c and φ of Q2 and Q3 loess, and the cohesion c tends to have a larger variability than φ. The effect of φ value variability on the reliability index of loess natural slope is generally greater than that of c value. Correspondingly, the variability of c value has a greater impact on the fill slope, which may be related to the rearrangement of soil particles and the redistribution of soil structure. The accuracy and applicability of the reliability analysis method are verified by comparative analysis. The method can be used for reliability analysis and slope rate optimization of loess slope without support of model test and monitoring data. If the failure probability of fill slope is required to be less than 10%, the relational expression between slope height and minimum slope coefficient is y=0.008 2x+1.422

引言
1 坡型及土体抗剪强度指标概率模型
2 c、φ变异性分析
3 黄土边坡可靠度分析
4 可靠度分析法与稳定性分析法的结果分析
5 填方边坡的坡率优化
6 结论

图1 工程分布图<br/>Fig.1 Engineering distribution

图1 工程分布图
Fig.1 Engineering distribution

图2 地层剖面图
Fig.2 Geological section

表1 黄土边坡坡型<br/>Tab.1 Parameters of loess slopes

表1 黄土边坡坡型
Tab.1 Parameters of loess slopes

表2 土体抗剪强度指标的参数表<br/>Tab.2 Statistical table of parameters of loess shear strength index

表2 土体抗剪强度指标的参数表
Tab.2 Statistical table of parameters of loess shear strength index

表3 分布假设检验结果<br/>Tab.3 Results of distribution hypothesis test

表3 分布假设检验结果
Tab.3 Results of distribution hypothesis test

图3 c、φ值分布<br/>Fig.3 Distribution of c、φ value

图3 c、φ值分布
Fig.3 Distribution of c、φ value

图4 c、φ值的变异系数<br/>Fig.4 Variation coefficient of c、φ value

图4 c、φ值的变异系数
Fig.4 Variation coefficient of c、φ value

表4 c、φ值的变异系数组合<br/>Tab.4 Variation coefficient combination of c、φ value

表4 c、φ值的变异系数组合
Tab.4 Variation coefficient combination of c、φ value

图5 不同高度自然边坡的可靠性指数<br/>Fig.5 Reliability index of natural slope with different heights

图5 不同高度自然边坡的可靠性指数
Fig.5 Reliability index of natural slope with different heights

图6 不同高度填方边坡的可靠性指数<br/>Fig.6 Reliability index of fill slope with different heights

图6 不同高度填方边坡的可靠性指数
Fig.6 Reliability index of fill slope with different heights

图7 模型边坡滑移面<br/>Fig.7 Slip surface of model slope

图7 模型边坡滑移面
Fig.7 Slip surface of model slope

图8 边坡高度与安全系数的关系曲线<br/>Fig.8 Relation curve of slope height and safety factor

图8 边坡高度与安全系数的关系曲线
Fig.8 Relation curve of slope height and safety factor

图9 不同坡比下边坡失效概率<br/>Fig.9 Probability of failure of different slope ratio

图9 不同坡比下边坡失效概率
Fig.9 Probability of failure of different slope ratio

图10 不同坡高与最小坡比的关系(Pf<10%)<br/>Fig.10 Relationship between slope height and the minimum slope ratio(Pf<10%)

图10 不同坡高与最小坡比的关系(Pf<10%)
Fig.10 Relationship between slope height and the minimum slope ratio(Pf<10%)

[1] 陈立宏,陈祖煜,刘金梅.土体抗剪强度指标的概率分布类型研究[J]. 岩土力学,2005(1): 37-40,45.
[2]LI Xibing, GONG Fengqiang. A method for fitting probability distributions to engineering properties of rock masses using Legendre orthogonal polynomials[J]. Structural Safety, 2009, 31(4):335-343.
[3]蒋水华,魏博文,姚池,杨建华.考虑概率分布影响的低概率水平边坡可靠度分析[J].岩土工程学报,2016,38(6):1071-1080.
[4]黄景华,陈朝晖,莫玻,等.参数特性及分布形式对边坡稳定可靠性的影响分析[J].四川大学学报(工程科学版),2014,46(3):23-30.
[5]方汕澳,许强,修德皓等.基于斜率模型的突发型黄土滑坡失稳时间预测[J].水文地质工程地质, 2021, 48(4): 169-179.
[6]叶伟林,康丽娟,安亚鹏等.甘肃永靖焦家村上庄2·28滑坡特点及成因分析[J].兰州大学学报(自然科学版),2021,57(3):369-375,381.
[7]YANG Dongdong, QIU Haijun, PEI Yanqian, et al. Spatial and temporal evolution of the infiltration characteristics of a loess landslide[J]. Isprs International Journal of Geo-Information, 2020,9(1):1-13.
[8]SHI J S, WU L Z, WU S R, et al. Analysis of the causes of large-scale loess landslides in Baoji, China[J]. Geomorphology, 2016, 264:109-117.
[9]龚伟翔,张晓超,裴向军,等.基于高陡交填界面软弱带影响下黄土填方边坡失稳模式研究[J/OL].工程地质学报, {3}{4}{5}: 1-11[2021-07-19].https://doi.org/10.13544/j.cnki.jeg.2020-250.
[10]谢永利,刘新荣,晏长根,等. 特殊岩土体工程边坡研究进展[J].土木工程学报,2020,53(9):93-105.
[11]梅源,胡长明,魏弋峰,等. Q2、Q3黄土深堑中高填方地基变形规律离心模型试验研究[J].岩土力学,2015,36(12):3473-3481.

₂

₃

[12]CHENG Yuxiang, HUO Aadi, ZHAO Zhixin, et al. Analysis of loess fracture on slope stability based on centrifugal model tests[J]. Bulletin of Engineering Geology and the Environment, 2021(4):1-11.
[13]ZHUANG Jianqi, PENG Jianbing, XU Yonglong, et al. Assessment and mapping of slope stability based on slope units: A case study in Yan'an, China[J]. Journal of Earth System Science, 2016, 125(7):1439-1450.
[14]何秉顺,马东亮,王庆苗,等.淮河堤防土体抗剪强度指标概率模型与参数优化估计[J].中国水利水电科学研究院学报,2010,8(3):195-200.
[15]苏卫卫,黄宏伟,张洁.上海软黏土抗剪强度指标概率分布类型研究[J].地下空间与工程学报,2012,8(S2): 1695-1699.
[16]崔洁,江权,冯夏庭,等.岩石抗剪强度参数的理论概率分布形态研究[J].岩土力学,2015,36(5):1261-1274.
[17]KIYONOBU K,ANDREW J W. Effect of spatial variability on the slope stability using random field numerical limit analysis[J]. Georisk Assessment and Management of Risk for Engineered Systems and Geohazards,2015,10(1):42-54.
[18]QI Xiaohui, LI Dianqing. Effect of spatial variability of shear strength parameters on critical slip surfaces of slopes[J].Engineering Geology, 2018: S0013795217317209.
[19]郑亚楠,侯晓坤,李萍,等.晋西隰县—离石地区黄土高边坡可靠度研究[J].工程地质报,2014,22(3):372-378.
[20]JIANG S H, LI D Q, CAO Z J, et al. Efficient system reliability analysis of slope stability in spatially variable soils using Monte Carlo simulation[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2015 141(2): 04014096.
[21]宫凤强,黄天朗,李夕兵. 岩土抗剪强度参数的最优概率分布函数推断方法[J].岩土工程报, 2016, 38(S2): 204-209.
[22]CHO S E. Probabilistic assessment of slope stability that considers the spatial variability of soil properties[J].Journal of Geotechnical and Geoenvironmental Engineering, 2010 136(7): 975-984.
[23]胡长明,梅源,刘增荣,等.湿陷性黄土高贴坡变形模式和稳定性分析[J].岩石力学与工程学报,2012,31(12):2585-2592.

备注

引言

1 坡型及土体抗剪强度指标概率模型

2 c、φ变异性分析

3 黄土边坡可靠度分析

4 可靠度分析法与稳定性分析法的结果分析

5 填方边坡的坡率优化

6 结论

期刊信息

备注

引言