Email Alerts
RSS
Hydromechanical coupling analysis of dynamic response of seepage slope under earthquake
-
摘要: 运用有限差分软件FLAC3D，建立某一赋含地下水的顺层岩质边坡三维模型，基于Finn动孔压增长模型，对边坡在地震作用下的加速度响应规律作了流固耦合分析，并就地下水对边坡塑性区分布的影响作了简要分析。数值计算结果表明：含地下水边坡的地震动峰值加速度PGA放大系数和坡顶加速度均大于无水边坡，地下水位升高时，PGA放大系数和坡顶加速度呈波动变化，当边坡土体处于完全饱和状态时，两者均明显增大；坡脚加速度随水位变化也呈波动状态，当边坡土体处于完全饱和状态时，同样明显增大；含地下水边坡的PGA放大系数等值线比不含地下水时的曲线分布更为杂乱，规律性较差，但仍具有明显的加速度垂直放大效应和临空面放大效应；表面风化层的塑性区随水位升高，其拉剪共同作用破坏单元逐渐增加，表面边坡的破坏效应逐渐增大。综合加速度、坡顶位移和塑性区分布来看，地下水对地震作用下顺层岩质边坡的稳定不利。Abstract: A 3D model for a rock bedded slope considering groundwater fluctuation is established by the finite difference software FLAC3D. Firstly, the hydromechanical coupling effect is considered on the basis of the dynamic response and a dynamic pore-pressure model, and the acceleration response of this seepage slope under the seismic action is studied. Then a brief analysis of the groundwater effects on the distribution of the plastic zones of the slope was made. The numerical simulation results show that the peak ground acceleration (PGA) amplification coefficients and the acceleration of the top of the slope are greater than those of the slope without considering groundwater fluctuation. As the groundwater level rises, the values of PGA amplification coefficients and the slope acceleration of the top of the slope are in the fluctuation conditions. However, when the whole slope is in a saturated state, two parameters mentioned above (i.e., the PGA amplification coefficients and the acceleration of the top of the slope) increase substantially. The acceleration of the toe of the slope also fluctuates as the groundwater level changes and a significant increase also occurs when the whole slope is in the saturated state. Moreover, the PGA amplification coefficient isoline distribution of the seepage slope is more 'messy' and has worse regularity than that of the slope without considering groundwater. The contour of the seepage slope still obviously reflects the vertical acceleration amplification effect and free face acceleration amplification effect. In order to analyze the damage conditions of the slope, the distribution of the plastic zones is analyzed. It is found that the plastic zones are mainly distributed in the surface weathered layer. Moreover, the plastic deformations are caused by the tensile shear interaction with the rising of the groundwater level. It proves that the damage effects of the groundwater under the seismic action on the slope increase. Comprehensive analysis of the acceleration response, the displacement of the slope top and the distribution of the plastic zones show that the groundwater is unfavorable to the seismic stability of the bedding rock slope.
-
Key words:
- rock bedded slope /
- groundwater /
- earthquake /
- dynamic pore pressure model /
- acceleration response
-
图 4 监测点超孔隙水压力变化时程
Figure 4. Change process of excess pore water pressure at monitoring points
图 5 不同水位下的PGA放大系数等值线
Figure 5. Contour map of PGA amplification factor under different water levels
图 6 不同水位下坡顶、坡脚加速度峰值
Figure 6. Peak acceleration at top and toe of slope under different water levels
图 8 不同水位下坡顶和坡脚加速度时程对比
Figure 8. Comparison between acceleration histories of top and toe of slope under different water levels
图 9 两种情况下坡顶x向最大位移时程曲线
Figure 9. Time history curves of maximum displacement on top of slope in x direction
图 12 不同水位下的塑性区最大剪应变增量
Figure 12. Max shear strain increments of plastic zone under different water levels
表 1 边坡及地下水物理力学参数
Table 1. Physico-mechanical parameters of slope and groundwater
岩层 体积模量/
GPa剪切模量/
GPa抗拉强度/
MPa岩体密度/
(kg·m-3)黏聚力/
MPa内摩擦角/
(°)流体模量/
GPa渗透系数/
(m·s-1)孔隙率 表面风化层 3.04 1.65 0.1 2 600 0.075 26 0.2 1×10-2 0.25 基岩 10.7 7.38 2.5 2 700 15 54.5 0.2 1×10-4 0.25 
下载: 导出CSV
-
[1] 何蕴龙, 陆述远.岩石边坡地震作用近似计算方法[J].岩土工程学报, 1998, 20(2): 66-68. http://www.cnki.com.cn/Article/CJFDTOTAL-YTGC802.018.htm HE Yunlong, LU Shuyuan. A method for calculating the seismic action in rock slope[J]. Chinese Journal of Geotechnical Engineering, 1998, 20(2): 66-68. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-YTGC802.018.htm [2] 祁生文.单面边坡的两种动力反应形式及其临界高度[J].地球物理学报, 2006, 49(2): 518-523. http://www.cnki.com.cn/Article/CJFDTOTAL-DQWX200602025.htm QI Shengwen. Two patterns of dynamic responses of single-free-surface slopes and their threshold height[J]. Chinese Journal of Geophysics, 2006, 49(2): 518-523. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-DQWX200602025.htm [3] 祁生文, 伍法权, 刘春玲, 等.地震边坡稳定性的工程地质分析[J].岩石力学与工程学报, 2004, 23(16): 2792-2797. doi: 10.3321/j.issn:1000-6915.2004.16.024 QI Shengwen, WU Faquan, LIU Chunling, et al. Engineering geology analysis of stability of slope under earthquake[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(16): 2792-2797. (in Chinese) doi: 10.3321/j.issn:1000-6915.2004.16.024 [4] 言志信, 张刘平, 曹小红, 等.地震作用下顺层岩质边坡动力响应规律及变形机制研究[J].岩土工程学报, 2011, 33(增1): 54-58. http://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2011S1011.htm YAN Zhixin, ZHANG Liuping, CAO Xiaohong, et al. Dynamic response and deformation mechanism of a bedding rock slope under earthquakes[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(Suppl1): 54-58. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2011S1011.htm [5] 言志信, 高乐, 彭宁波, 等.顺层岩质边坡地震动力响应研究[J].岩土力学, 2012, 33(增2): 85-90. http://youxian.cnki.com.cn/yxdetail.aspx?filename=YTLX20170228000&dbname=CAPJ2015 YAN Zhixin, GAO Le, PENG Ningbo, et al. A study of dynamic response of bedding rock slope under earthquakes[J]. Rock and Soil Mechanics, 2012, 33(Suppl2): 85-90. (in Chinese) http://youxian.cnki.com.cn/yxdetail.aspx?filename=YTLX20170228000&dbname=CAPJ2015 [6] 徐光兴. 地震作用下边坡工程动力响应与永久位移分析[D]. 成都: 西南交通大学, 2010. XU Guangxing. Research on the dynamic responses and permanent displacement of slope under earthquake[D]. Chengdu: Southwest Jiaotong University, 2010. (in Chinese) [7] 许强, 黄润秋. 5.12汶川大地震诱发大型崩滑灾害动力特征初探[J].工程地质学报, 2008, 16(6): 721-729. http://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ200806001.htm XU Qiang, HUANG Runqiu. Kinetics characteristics of large landslides triggered by May 12th Wenchuan earthquake[J]. Journal of Engineering Geology, 2008, 16(6): 721-729. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ200806001.htm [8] ITASCA Consulting Group. FLAC3D Version 4.0 (fast lagrangian analysis of continua in 3 dimensions) user's manual[M]. USA: Itasca Consulting Group, 2009. [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): 57-62. doi: 10.3969/j.issn.1009-1742.2002.10.011 ZHENG Yingren, ZHAO Shangyi, ZHANG Luyu. Slope stability analysis by strength reduction FEM[J]. Engineering Science, 2002, 4(10): 57-62. (in Chinese) doi: 10.3969/j.issn.1009-1742.2002.10.011 [10] 陈育民, 徐鼎平. FLAC/ FLAC3D基础与工程实例[M]. 2版.北京:中国水利水电出版社, 2013. CHEN Yumin, XU Dingping. Basic theory and engineering examples of FLAC/ FLAC3D[M]. 2nd ed. Beijing: China Water and Power Press, 2013. (in Chinese) [11] MARTIN G R, FINN W D L, SEED H B. Fundamentals of liquefaction under cyclic loading[J]. Journal of the Geotechnical Engineering Division, ASCE, 1982, 108(7): 835-952. http://cedb.asce.org/CEDBsearch/record.jsp?dockey=0024463 [12] 胡聿贤.地震工程学[M].北京:地震出版社, 1988. HU Yuxian. Seismic engineering[M]. Beijing: Earthquake Press, 1988. (in Chinese) [13] 吕西林, 任红梅, 李培振, 等.液化场地自由场体系的数值分析及振动台试验验证[J].岩石力学与工程学报, 2009, 28(增2): 4046-4053. http://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2009S2114.htm LYU Xilin, REN Hongmei, LI Peizhen, et al. Numerical analysis of free field system in liquefiable site and validation of shaking table tests[J]. Chinese Journal of Rock Mechanics and Engineering, 2009, 28(Suppl2): 4046-4053. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2009S2114.htm [14] 王存玉. 地震条件下二滩水库岸坡稳定性研究[M]//岩体工程地质力学问题(七). 北京: 科学出版社, 1987. WANG Cunyu. Study on the slope stability of Ertan reservoir under seismic excitation[M]// Geomechanics problems in rock engineerings (Ⅶ). Beijing: Science Press, 1987. (in Chinese) -
点击查看大图
图(12) / 表 (1)
计量
- 文章访问数: 887
- HTML全文浏览量: 37
- PDF下载量: 451
- 被引次数: 0
