Distribution of acceleration and empirical formula for calculating maximum acceleration of rockfill dams

Abstract

To find the distribution patterns of dynamic amplification coefficients for dams subjected to earthquake, 3D seismic responses of concrete-faced rockfill dams with different heights and different shapes of river valley were analyzed by using the equivalent-linear model. Statistical analysis was also made to the seismic coefficient, and an empirical formula for calculating the maximum acceleration was provided. The results indicate that under the condition of the same dam height and the same base acceleration excitations, with the increase of the river valley width, the position of the maximum acceleration on the axis of the top of the dam moves from the center to the riversides symmetrically. For the narrow valleys, the maximum acceleration occurs in the middle of the axis at the top of the dam; for wide valleys the maximum acceleration appears near the riversides. The result negates the application of 2D dynamical computation for wide valleys, and shows that for the seismic response of high concrete-faced rockfill dams, the seismic coefficient along the axis should be given, except for that along the dam height. Seismic stability analysis of rockfill dams using pseudo-static method can be modified according to the formula.

Keywords

concrete-faced rockfill dam / 3D dynamical response analysis / equivalent-linear method / acceleration / seismic coefficient / statistical analysis

References

[1] ChenS.-s., HuoJ.-p., ZhangW.-min.. Analysis of effects of “5.12” Wenchuan earthquake on Zipingpu concrete face rock-fill dam [J]. Chinese Journal of Geotechnical Engineering, 2008, 30(6): 795-801

[2] RampelloS., CasconeE., GrossoN.. Evaluation of the seismic response of a homogeneous earth dam [J]. Soil Dynamics and Earthquake Engineering, 2009, 29(5): 782-798

[3] HuangY., YashimaA., SawadaK., ZhangF.. A case study of seismic response of earth embankment foundation on liquefiable soils [J]. Journal of Central South University of Technology, 2009, 16(6): 994-1000

[4] LiuH.-x., LiN., LiaoX.. Effective stress analysis method of seismic response for high tailings dam [J]. Journal of Central South University of Technology, 2007, 14(1): 129-134

[5] LinH., CaoP., GongF.-qiang.. Directly searching method for slip plane and its influential factors based on critical state of slope [J]. Journal of Central South University of Technology, 2009, 16(2): 131-135

[6] ChengY. M., LansivaaraT., WeiW. B.. Two-dimensional slope stability analysis by limit equilibrium and strength reduction methods [J]. Computers and Geotechnics, 2007, 34(3): 137-150

[7] SuY.-h., ZhaoM.-h., ZhangY.-ying.. Numerical method of slope failure probability based on Bishop model [J]. Journal of Central South University of Technology, 2008, 15(1): 100-105

[8] OyangurenP., NiciezaC. G., FernandezM. I., PalacioC. G.. Stability analysis of Llerin rockfill dam: An in situ direct shear test [J]. Engineering Geology, 2008, 100(3/4): 120-130

[9] YangX.-l., HuangFu.. Slope stability analysis considering joined influences of nonlinearity and dilation [J]. Journal of Central South University of Technology, 2009, 16(2): 292-296

[10] ZhengH., ThamL. G., LiuD. F.. On two definitions of the factor of safety commonly used in the finite element slope stability analysis [J]. Computers and Geotechnics, 2006, 33(3): 188-195

[11] HuangM.-s., JiaC.-qin.. Strength reduction FEM in stability analysis of soil slopes subjected to transient unsaturated seepage [J]. Computers and Geotechnics, 2009, 36(1): 93-101

[12] ShukhaR., BakerR.. Design implications of the vertical pseudo-static coefficient in slope analysis [J]. Computers and Geotechnics, 2008, 35(1): 86-96

[13] China Institute of Water Resources and Hydropower Research. Specifications for seismic design of hydraulic structures (SL203-97) [S]. Beijing: China Water Power Press, 1998.

[14] ZhangR., ChiS.-c., LinG.. Research on slope seismic stability analysis of high earth-rock dams [J]. Journal of Hydroeletric Engineering, 2008, 27(4): 83-88

[15] ZhangR., ChiS.-c., LinG.. Discussion on seismic coefficient of high earth-rock dams and its influence on dam slope seismic stability [J]. Rock and Soil Mechanics, 2008, 29(4): 1072-1076

[16] LiJ.-j., HanG.-c., KongX.-jing.. 3-D seismic response of Guanmenshan concrete faced rockfill dam [J]. Journal of Hydraulic Engineering, 1994, 2: 76-84

[17] KONG Xian-jing, LOU Shu-lian, ZOU De-gao, JIA Ge-xu, HAN Guo-cheng. The equivalent dynamic shear modulus and equivalent damping ratio of rockfill material for dam [J]. Journal of Hydraulic Engineering, 2001(8): 20–25.(in Chinese)

[18] LiJ.-j., HanG.-c., LinG.. A simplified formula of the natural period of CFRD [J]. Journal of Vibration Engineering, 1995, 8(3): 274-280