考虑土骨架加速度效应的海床动力反应及其影响因素分析
Numerical analyses and parametric studies of dynamic response of seabed considering the effect of soil skeleton acceleration
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摘要: 由Biot二维广义动力固结理论的形式基本控制方程出发,忽略孔隙流体的加速度,提出了饱和海床动力反应的时域有限元数值解法.联立静力平衡条件和Biot固结方程的退化法所得到的数值解可视为其特例.在比较算例中,退化法得到的超静孔压和有效应力幅值沿海床深度的分布与解析解一致.一般情况下,土骨架的加速度对海床的有效应力和超静孔压影响很小,控制方程可以退化为Biot理论.成层海床上部的粗砂层不会使超静孔压幅值在海床表面下较浅的深度内迅速衰减,难以改变海床的瞬时循环液化深度.Abstract: Based on the u-p form of the gener alized formulation of two-dimensional Biots theory of dynamic consolidation,the finite element numerical procedure in time domain is developed to evaluate dynamic response of saturated seabed.The governing equations which are composed of static equilibrium conditions and Biots consolidation equation can be regarded as a special case.In comparative examples,the results from the degenerated method proposed agree well with the analytical solutions.In general,the effect of soil skeleton acceleration on effectivest resses and pore pressure can be neglected and the governing equations can be expressed by Biots theory. The upper coarse sand layer of layered seabed will not reduce the amplitudes of pore pressure remarkably at the shallow zone near the seabed surface,therefore the possible maximum liquefaction depth will not change.
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Key words:
- consolidation theory /
- finite element /
- dynamic response /
- linear wave /
- seabed /
- layered seabed /
- liquefaction
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YAMAMOTO T, SELLMEIHER H L, HIJUM E V. On the response of a porous-elastic bed to water waves[J]. J FluidMech, 1978, 87(1):193-206. MADSEN O S. Wave-induced pore pressure and effective stresses in a porous bed[J]. Geotechnique, 1978, 28(4):377-393. MEI C C, FODA M A. Wave-induced responses in a fluid-filled poro-elastic solid with a free surface a boundary layertheory[J]. Geophy J Roy Astr Soc, 1981, 66:597-631. HSU J R C, JENG D S, TSAI C P. Short-crested wave induced soil response in a porous seabed of infinite thickness[J]. IntJ Numer Analyt Meth Geomech, 1994, 18(11):785-807. JENG D S, HSU J R C. Wave-induced response in a nearly saturated sea-bed of finite thickness[J]. Geotechnique, 1996, 46(3):427-440. JENG D S, LIN Y S. Non-linear wave-induced response of porous seabed:a finite element analysis[J]. Int J NumerAnalyt Meth Geomech, 1997, 21:15-42. GATMIRI B. A simplified finite element analysis of wave-induced effective stresses and pore pressures in permeable seabed[J]. Geotechnique, 1990, 40(1):15-30. ZIENKIEWICZ O C, BETTESS P. Soils and other saturated media under transient, dynamic conditions:generalformulation and the validity of various simplifying assumptions[A]. Pande G N, Zienkiewicz. O C, ed. Soil MechanicsTransient and Cyclic Loads[M]. New York:John Wiley and Sons Ltd, 1982. 1-16. ZIENKIEWICZ O C, SHIOMI T. Dynamic behaviour of saturated porous media:the generalized Biot formulation and itsnumerical solution[J]. Int J Numer and Analyt Meth Geomech, 1984, 8:71-96. ZIENKIEWICZ O C, PAUL D K, CHAN A H C. Unconditionally stable staggered solution procedure for soil-pore fluidinteraction problem[J]. Int J Numer Methods Eng, 1988, 26:1 039-1 055. ZEN K, YAMAZAKI H. Mechanism of wave-induced liquefaction and densification in seabed[J]. Soils and Foundations,1990, 30(4).-90-104. 王拣,栾茂田,郭莹.波浪作用下海床动力反映有限元数值模拟与液化分析[J].大连理工大学学报,2001,41(2):216-222.
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