-
摘要: 针对顺层岩质路堑边坡稳定的关键影响因素, 采用有限元强度折减法, 研究了边坡高度、坡顶堆载及工程防护对具一组贯通软弱结构面的顺层岩质边坡模型稳定性的影响, 并与传统极限平衡法进行了对比验证。研究结果表明: 边坡坡度大于岩层倾角时对稳定不利, 安全系数随边坡高度增加而降低; 坡顶堆载时, 安全系数的降低取决于荷载和贯通塑性区的相对位置; 挡土墙或锚杆通过对塑性区贯通带的阻截使塑性区转移到其他更薄弱的结构面, 从而提高安全系数, 塑性区贯通带的转移去向取决于初始支撑强度; 基于Drucker-Prager屈服准则的安全系数有限元计算结果比基于莫尔-库仑准则的传统极限平衡法计算结果平均高出约22%, 与郑颖人等约为25%的研究成果非常接近, 说明有限元强度折减法可行。Abstract: According to the key influencing factors of bedding rock cutting slope stability, the influences of slope height, load on the top of slope and engineering protection on the stability of bedding rock slope model with a group of the runned-through planes of weakness were studied by nonlinear FEM srength reduction method, and traditional limit equilibrium method was used for comparison and verification.Analysis result shows that when the slope grade is larger than rock obliquity, it is disadvantageous to slope stability, and safety coefficient decreases with the increase of slope height.When load is applied on the top of slope, the reduction of safety coefficient depends on the relative position between load and runned-through plastic zone.Retaining wall or anchor rod can increase slope safety coefficient by blocking and intercepting runned-through plastic zone, and plastic zone moves to other more weak structural plane, its moving direction depends on initial sustaining strength.The finite element calculation result of safety coefficient based on Drucker-Prager yield criterion is about 22% higher than the result of traditional limit equilibrium method based on Mohr-Coulomb criterion, it is very close to the research result of about 25% by Zheng Ying-ren, et al, so finite element srength reduction method is feasible.
-
表 1 材料特性
Table 1. Material properties
表 2 安全系数计算结果
Table 2. Calculation results of safety factors
表 3 安全系数比较
Table 3. Comparison of safety factors
表 4 各地质层材料特性
Table 4. Material properties of geological layers
表 5 不同方法求得的安全系数
Table 5. Safety factors acquired from different methods
-
[1] ZIENKIEWICZ O C, HUMPHESON C, LEWIS R W. Associated and non-associated visco-plasticity and plasticity in soil mechanics[J]. Geotechnique, 1975, 25(4): 671-689. doi: 10.1680/geot.1975.25.4.671 [2] GRIFFITHS D V, LANE P A. Slope stability analysis by finite elements[J]. Geotechnique, 1999, 49(3): 387-403. doi: 10.1680/geot.1999.49.3.387 [3] 年廷凯, 栾茂田, 杨庆, 等. 基于强度折减弹塑性有限元方法的路堤稳定性分析[J]. 中国公路学报, 2008, 21(2): 18-22. doi: 10.3321/j.issn:1001-7372.2008.02.004NIAN Ting-kai, LUAN Mao-tian, YANG Qing, et al. Sta-bility analysis of embankment based on shear strength reduc-tion elasto-plastic FEM[J]. China Journal of Highway and Transport, 2008, 21(2): 18-22. (in Chinese). doi: 10.3321/j.issn:1001-7372.2008.02.004 [4] DAWSON E M, ROTH W H, DRESCHER A. Slope stability analysis by strength reduction[J]. Geotechnique, 1999, 49(6): 835-840. doi: 10.1680/geot.1999.49.6.835 [5] 宋二祥. 土工结构安全系数的有限元计算[J]. 岩土工程学报, 1997, 19(2): 1-7. doi: 10.3321/j.issn:1000-4548.1997.02.001SONG Er-xiang. Finite element analysis of safety factor for soil structures[J]. Chinese Journal of Geotechnical Engineer-ing, 1997, 19(2): 1-7. (in Chinese). doi: 10.3321/j.issn:1000-4548.1997.02.001 [6] 吕庆, 孙红月, 尚岳全. 强度折减有限元法中边坡失稳判据的研究[J]. 浙江大学学报: 工学版, 2008, 42(1): 83-87. doi: 10.3785/j.issn.1008-973X.2008.01.016LU Qing, SUN Hong-yue, SHANG Yue-quan. Slope failure criteria of shear strength reduction finite element method[J]. Journal of Zhejiang University: Engineering Science, 2008, 42(1): 83-87. (in Chinese). doi: 10.3785/j.issn.1008-973X.2008.01.016 [7] 林杭, 曹平, 李江腾, 等. 层状岩质边坡破坏模式及稳定性的数值分析[J]. 岩土力学, 2010, 31(10): 3300-3304. doi: 10.3969/j.issn.1000-7598.2010.10.043LIN Hang, CAO Ping, LI Jiang-teng, et al. Numerical analy-sis of failure modes and stability of stratified rock slopes[J]. Rock and Soil Mechanics, 2010, 31(10): 3300-3304. (in Chinese). doi: 10.3969/j.issn.1000-7598.2010.10.043 [8] 江学良, 曹平, 杨慧. 层状岩质边坡开挖过程的有限元模拟[J]. 岩土力学, 2006, 27(11): 1935-1940. doi: 10.3969/j.issn.1000-7598.2006.11.014JIANG Xue-liang, CAO Ping, YANG Hui. Simulation of stage excavation for stratified rock slope by using two-dimen-sional elastoplastic finite element method[J]. Rock and SoilMechnics, 2006, 27(11): 1935-1940. (in Chinese). doi: 10.3969/j.issn.1000-7598.2006.11.014 [9] 郑颖人, 赵尚毅, 张鲁渝. 用有限元强度折减法进行边坡稳定分析[J]. 中国工程科学, 2002, 4(10): 57-61, 78. doi: 10.3969/j.issn.1009-1742.2002.10.011ZHENG Ying-ren, ZHAO Shang-yi, ZHANG Lu-yu. Slope stability analysis by strength reduction FEM[J]. Engineering Science, 2002, 4(10): 57-61, 78. (in Chinese). doi: 10.3969/j.issn.1009-1742.2002.10.011 [10] 郑颖人, 赵尚毅, 邓楚键, 等. 有限元极限分析法发展及其在岩土工程中的应用[J]. 中国工程科学, 2006, 8(12): 39-61. doi: 10.3969/j.issn.1009-1742.2006.12.005ZHENG Ying-ren, ZHAO Shang-yi, DENG Chu-jian, et al. Development of finite element limit analysis method and its applications in geotechnical engineering[J]. Engineering Science, 2006, 8(12): 39-61. (in Chinese). doi: 10.3969/j.issn.1009-1742.2006.12.005 [11] 张鲁渝, 郑颖人, 赵尚毅, 等. 有限元强度折减系数法计算土坡稳定安全系数的精度研究[J]. 水利学报, 2003, 34(1): 21-27. https://www.cnki.com.cn/Article/CJFDTOTAL-SLXB200301004.htmZHANG Lu-yu, ZHENG Ying-ren, ZHAO Shang-yi, et al. The feasibility study of strength-reduction method with FEM for calculating safety factors of soil slope stability[J]. Journal of Hydraulic Engineering, 2003, 34(1): 21-27. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-SLXB200301004.htm [12] 赵尚毅, 郑颖人, 刘明维, 等. 基于Drucker-Prager准则的边坡安全系数定义及其转换[J]. 岩石力学与工程学报, 2006, 25(增1): 2730-2734. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2006S1019.htmZHAO Shang-yi, ZHENG Ying-ren, LIU Ming-wei, et al. Definition and transformation of slope safety factor based on Drucker-Prager criterion[J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(S1): 2730-2734. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2006S1019.htm [13] 李保雄, 苗天德. 红层软岩顺层滑坡临滑预报的强度控制方法[J]. 岩石力学与工程学报, 2003, 22(增2): 2703-2706. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2003S2034.htmLI Bao-xiong, MIAO Tian-de. Strength controlling forecast method of critical landslide along red-soft-mudstone layer[J]. Chinese Journal of Rock Mechanics and Engineering, 2003, 22(S2): 2703-2706. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2003S2034.htm [14] 高大水, 徐年丰, 高银水, 等. 用混凝土阻滑键技术治理灰岩顺层滑坡[J]. 岩石力学与工程学报, 2005, 24(增2): 5433-5437. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2005S2029.htmGAO Da-shui, XU Nian-feng, GAO Yin-shui, et al. Appli-cation of concrete sliding resistant key to treating limestone bedding landslip[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(S2): 5433-5437. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2005S2029.htm [15] 许建聪, 尚岳全, 陈侃福, 等. 顺层滑坡弹塑性接触有限元稳定性分析[J]. 岩石力学与工程学报, 2005, 24(13): 2231-2236. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200513004.htmXU Jian-cong, SHANG Yue-quan, CHEN Kan-fu, et al. Elastoplastic contact FEM analysis of bedding landslide sta-bility[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(13): 2231-2236. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200513004.htm