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本文在考虑环境刚度效应和非匀阻效应的情况下,采用椭圆形震源简化模型,研究了走滑断层的地震烈度几何要素与震源参数之间的关系,初步建立了估计断层有效发震段长度、错动角、应力降和错动距离等参数的等震线法,并结合唐山、通海、炉霍和永善等震例进行了试算 相似文献
213.
笔者对×水电站库区左岸的渗漏进行了直角正交电网络模拟。圈定了裂隙发育强带及岩溶通道的位置,并用不同比例(对全区1:2000,对裂隙带1:500,对岩溶通道1:125)进行模拟,得出了渗漏量。其结果与实际资料基本吻合。 相似文献
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Development of Winkler model for static and dynamic response of caisson foundations with soil and interface nonlinearities 总被引:7,自引:0,他引:7
As an extension of the elastic multi-spring model developed by the authors in a companion paper [Gerolymos N, Gazetas G. Winkler model for lateral response of rigid caisson foundations in linear soil. Soil Dyn Earthq Eng; 2005 (submitted companion paper).], this paper develops a nonlinear Winkler-spring method for the static, cyclic, and dynamic response of caisson foundations. The nonlinear soil reactions along the circumference and on the base of the caisson are modeled realistically by using suitable couple translational and rotational nonlinear interaction springs and dashpots, which can realistically (even if approximately) model such effects as separation and slippage at the caisson–soil interface, uplift of the caisson base, radiation damping, stiffness and strength degradation with large number of cycles. The method is implemented in a new finite difference time-domain code, NL-CAISSON. An efficient numerical methodology is also developed for calibrating the model parameters using a variety of experimental and analytical data. The necessity for the proposed model arises from the difficulty to predict the large-amplitude dynamic response of caissons up to failure, statically or dynamically. In a subsequent companion paper [Gerolymos N, Gazetas G. Static and dynamic response of massive caisson foundations with soil and interface nonlinearities—validation and results. Soil Dyn Earthq Eng; 2005 (submitted companion paper).], the model is validated against in situ medium-scale static load tests and results of 3D finite element analysis. It is then used to analyse the dynamic response of a laterally loaded caisson considering soil and interface nonlinearities. 相似文献
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Sébastien Blaise Eric Deleersnijder Laurent White Jean-François Remacle 《Continental Shelf Research》2007
A three-dimensional finite-element model is used to investigate the tidal flow around Rattray Island, Great Barrier Reef, Australia. Field measurements and visual observations show both stable eddies developing at rising and falling tide in the wake of the island. The water turbidity suggests intense upwelling able to carry bed sediments upwards. Based on previous numerical studies, it remains unclear at this point whether the most intense upwelling occurs near the centre of the eddies or off the island's tips, closer to the island. All these studies resorted to a very simple turbulence closure, with a zero-equation model whereby the coefficient of vertical viscosity is computed via an algebraic expression. In this work, we aim at studying the influence of the turbulence closure on model results, with emphasis on the prediction of vertical motions. The Mellor and Yamada level 2.5 closure scheme is used and an increase in the intensity of vertical transport is observed. This increase is partly explained by the fact that the Mellor and Yamada model takes into account the hysteresis effect in the time variation of turbulence variables. The influence of the advection of turbulence variables is estimated to be negligible. By a better representation of transient coastal phenomena, the Mellor and Yamada level 2.5 turbulence closure improves the model to a significant degree. 相似文献
220.
Geometric modelling and object-oriented software concepts applied to a heterogeneous fractured network from the Grimsel rock laboratory 总被引:2,自引:0,他引:2
Thomas Kalbacher Ralph Mettier Chris McDermott Wenqing Wang Georg Kosakowski Takeo Taniguchi Olaf Kolditz 《Computational Geosciences》2007,11(1):9-26
Discrete fracture network simulations are computationally intensive and usually time-consuming to construct and configure.
This paper presents a case study with techniques for building a 3D finite element model of an inhomogeneous fracture network
for modelling flow and tracer transport, combining deterministic and stochastic information on fracture aperture distributions.
The complex intersected fractures represent a challenge for geometrical model design, mesh quality requirements and property
allocations. For the integrated and holistic modelling approach, including the application of numerical and analytical simulation
techniques, new object-oriented concepts in software engineering are implemented to ensure a resourceful and practicable software
environment. 相似文献