mm Fig. 1 Model design 80 m m 100 m C u = C c = C u C c m 0. 3 m 0. 5 m 1 30 cm

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1 GLOBAL GEOLOGY Vol. 35 No. 2 Jun GeoStudio 2007 TV TV A doi /j. issn Large-sized physical model of two-dimensional dam seepage field LI Peng-fei XU Pei-hua HAN Jing L Jin-zhi College of Construction Engineering Jilin University Changchun China Abstract Experiments were conducted in large scale sand tank to simulate the two-dimensional seepage process through large sand grain in dam foundation to analyze the variations of the seepage situation. Soil samples in different location were taken out to analyze their particles composition after seepage failure. Based on the parameters obtained from the experiments numerical analysis is conducted to simulate the seepage field using the software of GeoStudio 2007 whose results of the spatial distribution of the seepage field agreed well with those from experiments indicating the reasonable of the experimental model. Results showed that seepage deformation mainly occurred in dam foundation where the seepage path was short while there were no clear deformation along the upstream and downstream of the dam foundation. The seepage path changed greatly after seepage failure leading to the great increase of the volume of seepage flow thus accelerating the damage process. Key words seepage filed sand tank dam foundation seepage deformation % 1 52% xuph@ jlu. edu. cn

560 35 3 4-6 1 mm Fig. 1 Model design 80 m 100 1 m 100 m 7 8 1. 2 9 1. 2. 1 2 C u = 49. 51 C c = 10. 17 C u C c 11 1 1. 1 1. 8 m 0.

2 mm Fig. 1 Model design 80 m m 100 m C u = C c = C u C c m 0. 3 m 0. 5 m 1 30 cm 30 cm kpa 70 cm 30 cm 20 15cm 9 1 / cm Fig. 2 Testing particles analysis curve 40 cm 80 cm 10 cm

2 561 2 cm 1 R e 0. 01 31 cm 2 R = A /χ 12 h R e 119 71 89 < 500 1 k h 3 = 0. 661 m h 4 1 = 0. 995 m h = h 4 - h 3 = 0. 334 m Table 1 Pressure before and after piping erosion 13 k 1 = QL /Fh = 1.

3 cm 1 R e cm 2 R = A /χ 12 h R e < k h 3 = m h 4 1 = m h = h 4 - h 3 = m Table 1 Pressure before and after piping erosion 13 k 1 = QL /Fh = m 3 /s 1 ~ 1 1 ~ 2 2 ~ 1 2 ~ 2 2 ~ 3 k 2 = QL /Fh = m 3 /s /cm /cm ~ 1 3 ~ 2 3 ~ 3 3 ~ 4 4 ~ 1 /cm /cm ~ 2 4 ~ 3 4 ~ 4 5 ~ 1 5 ~ 2 /cm /cm ~ 3 5 ~ 4 6 ~ 1 6 ~ 2 6 ~ 3 / cm /cm m /s R e = vr v 1 v v = A χ k = k 1 + k 2 /2 = m 3 /s m 3 /s 3 30 cm 30 cm 10 cm Fig. 3 3 Comparison chart of permeate outlet downstream of dam before and after piping erosion

562 35 R e 5 R e 276 166 145 < 500 70 cm 30 cm 10 cm 2 Table 2 2 Permeability coefficient of different region /10-4 m 3 s - 1 1 2 3 4 5 K 1. 97 1. 03 9. 00 8. 15 7. 76 3. 19 2. 41 6 6 d 10 0. 2 mm 0.

4 R e 5 R e < cm 30 cm 10 cm 2 Table 2 2 Permeability coefficient of different region /10-4 m 3 s K d mm mm d cm d cm Table 3 Particle size of cumulation weight to 10% after 1. 3 seepage failure /cm 0 ~ ~ ~ ~ ~ 50 d 4 10 /mm % Fig. 4 4 Simulation dam surface soil samples before and after infiltration and sabotage < 0. 5 mm 4 5 mm % Table 4 Percentage of particles less than 5 mm in different layers after seepage failure % /cm 0 ~ ~ ~ ~ ~ cm < 30 cm < 0. 5 mm 2 30 cm 80 cm < 1 /2 /% GeoStudio2007SEEP /W

第2 期李鹏飞徐佩华等坝基二维渗流场的大尺寸物理模型试验 563 a. 10 cm b. 20 cm c. 30 cm d. 40 cm 图5 Fig. 5 渗透破坏后不同层位的照片 Pictures of different layer particles after seepage failure 验测得 2. 1 数值模型的建立数值模型范围为 1. 8 m 0. 5 m 0.

5 第2 期李鹏飞徐佩华等坝基二维渗流场的大尺寸物理模型试验 563 a. 10 cm b. 20 cm c. 30 cm d. 40 cm 图5 Fig. 5 渗透破坏后不同层位的照片 Pictures of different layer particles after seepage failure 验测得 2. 1 数值模型的建立数值模型范围为 1. 8 m 0. 5 m 0. 3 m 长深宽网格剖分后包含节点 457 个单元 418 个单元格 m m 图 7 试验开始时试验槽内为均匀砂样所以材料为同一属性只将材料划为一个大区管涌后试验槽发生不均匀破坏根据物理模型试验结果将渗透破坏后的模型槽分为三个区坝上游区模拟坝基区和坝下游区其中模拟坝基区从上至下又分为 5 个区图 7 由于所取砂样不均匀系数达到了 49 很容易形成管涌坝上游加到 2 m 水头就产生图6 Fig. 6 原状样和试验后各部分颗分曲线 Particles analysis curve of initial and each part after test particles 了管涌故边界条件为坝上游区表面 2 m 水头坝下游区表面 m 水头 2. 2 数值模拟结果分析图 8 和图 9 为渗透破坏前后的渗流矢量图两

564 35 Fig. 7 7 8 Mesh dissection of numerical model and calculation Fig. 8 Seepage vector of initial physical model division Fig. 9 9 10 Seepage vector after seepage failure Fig.

6 Fig Mesh dissection of numerical model and calculation Fig. 8 Seepage vector of initial physical model division Fig Seepage vector after seepage failure Fig. 10 Seepage path and equipotential line of initial physical model m /s 9 25 cm 30 cm Fig. 11 Seepage path and equlipotential line of after seepage failure m /s m /s 3 1 GeoStudio m /s m /s

7 cm ± J SU Bao-yu ZHAO Jian ZHANG Zhu-tian et al. Application of positive position model in the electronic simula- tion test of the spacial infiltration flow field of tailings 25 ~ 30 cm dams J. Metal Mines J GeoStudio ZHU Yue-ming CHEN Jian-yu GONG Dao-yong et al. 25 ~ 30 Refined solution to seepage in arch dam foundation with cm 30cm FEM J. Chinese Journal of Geotechnical Engineering 25 ~ 30 cm J ~ 30 cm JIANG Xue LIANG Xiu-juan XIAO Chang-lai et al. 4 Three-dimensional seepage analysis of tailings damming period J. Journal of Jilin University Earth Science E- 1 dition J WANG Gang-cheng HUANG Chao. Seepage analysis for 30 cm dam foundation and abutment of Jiangxiong reservior and J ZHENG Rui-hua ZHANG Ga ZHANG Jian-min et al. Large cohesion less soil permeability experiment sys- 1. tem and application J. Experimental Technology and J PIAO Ming-yue LI Xu-qian ZHAO Yu-hong et al. Effect factors of bound water content and penetration characteristics Management J of weak aquitard J. Global Geology 2011 TIAN Kan-liang ZHANG Hui-li LUO Bi-yu. Develop ment of a new-type apparatus for measuring seepage de- 2. formation J. Chinese Journal of Rock Mechanics and D Engineering Suppl ZHOU Zhi-wei. Couple modeling of seepage field and 9. temperature field for earth dam master s degree thesis J. D. Yangzhou Yangzhou University its leakage-proof plan evaluation J. Global Geology

8 CHEN Jian-sheng HE Wen-zheng WANG Shuang et al. Laboratory tests on development of seepage failure of overlying layer during piping of two-stratum dike foundation J. Chinese Journal of Geotechnical Engineering J LIU Jie CUI Yi-hao XIE Ding-song. Destructive tests on piping failure of sandy gravel layer of river dikes J. Chinese Journal of Geotechnical Engineering M TANG Da-xiong LIU You-rong ZHANG Wen-shu et al. Rock and soil engineering M. Beijing Geological Publishing House M. LIU Jie. Seepage stability and control of soil M. Beijing Water Power Press M GONG Xiao-nan. Soil mechanics M. Beijing China Building Industry Press

01-0982.doc

01-0982.doc 第 32 卷第 7 期岩土工程学报 Vol.32 No.7 2010 年 7 月 Chinese Journal of Geotechnical Engineering July 2010 沿海碎石回填地基上高能级强夯系列试验对比研究年廷凯 1,2, 水伟厚 3, 李鸿江 4, 杨庆 1,2, 王玉立 (1. 大连理工