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591.
Liner design for waste disposal sites 总被引:5,自引:0,他引:5
Since the beginning of the 1980s waste disposal has become a particularly sensitive issue. This has led to the development
of new legislations in the European Community and internationally which resulted in an array of regulations concerning landfill
liner design. This paper comments on different "engineered" containment methods with particular reference to landfill liner
design. Suggestions based on the review of the different methodologies are given and a case study is presented.
Received: 25 February 1997 · Accepted: 16 December 1997 相似文献
592.
Pragmatic experimental design requires objective consideration of several classes of information including the survey goals, the range of expected Earth responses, acquisition costs, instrumental capabilities, experimental conditions and logistics. In this study we consider the ramifications of maximizing model parameter resolution through non-linear experimental design. Global optimization theory is employed to examine and rank different EM sounding survey designs in terms of model resolution as defined by linearized inverse theory. By studying both theoretically optimal and heuristic experimental survey configurations for various quantities of data, it is shown that design optimization is critical for minimizing model variance estimates, and is particularly important when the inverse problem becomes nearly underdetermined. We introduce the concept of robustness so that survey designs are relatively immune to the presence of potential bias errors in important data. Bias may arise during practical measurement, or from designing a survey using an appropriate model. 相似文献
593.
Izuru Takewaki Tsuneyoshi Nakamura Kitae Hirayama 《Soil Dynamics and Earthquake Engineering》1998,17(3):153-163
A two-step stiffness design procedure is developed for a moment-resisting planar frame supported by a prescribed two-dimensional finite-element ground-pile system. In the first step, a hybrid inverse eigenmode problem is formulated and its solution is derived in an analytical form. A difficulty resulting from the existence of multiple interface nodes is overcome by incorporating a deformation constraint into a set of linear equations for finding the lowest-mode displacements at the interface nodes and in the ground. In the second step, the fundamental natural frequency of the combined system and the lowest mode-strain ratios in the frame specified in the first step are regarded as the parameters for adjusting the mean peak seismic member-end strains to their specified values. If the fundamental natural frequency of the frame with a fixed-base happens to be close to that of the ground, a difficulty arises in the two-step stiffness design procedure because of an irregular response amplification and of the non-predominance of the lowest-mode components. A new practical design procedure of rapid convergence is proposed such that an initial design is found for a stiff ground and that a sequence of stiffness designs is generated with respect to a ground stiffness parameter without any differential coefficient of series expansion. The accuracy of the model utilized in this paper and the validity of the present stiffness design procedure are verified through time-history response analysis. 相似文献
594.
595.
低周反复荷载作用下复合耗能支撑钢筋混凝土框架结构的抗震性能试验研究 总被引:3,自引:0,他引:3
本文介绍了三榀钢支撑钢筋混凝土框架结构(包括两榀复合耗能支撑框架、一榀普通支撑框架)在低周反复荷载作用下的试验结果。对复合耗能支撑框架结构在低周反复荷载作用下的工作性能(包括受力性能、破坏形态、滞回曲线、骨架曲线、延性和耗能能力等)进行了探讨,揭示了复合耗能支撑框架结构良好的抗震性能。 相似文献
596.
遗传规划在岩石力学中的应用 总被引:1,自引:0,他引:1
本文探讨了遗传规划这一新的优化方法在岩石力学参数确定中的应用。由于影响岩石力学性能的各因素之间关系不明确,而遗传规划特别适用于各影响因素之间因果关系不明确的复杂非线性问题。它为预测岩石力学性能提供了一条新的技术途径。通过例子,说明该方法的实用性。 相似文献
597.
Motif的功能概要地说就是对各种Widget的创建、管理和回调。利用Motif工具库为该系统设计人机交互界面的主要步骤为:根据有限元法地震正演模拟系统的总体结构,编程设计系统各层次结构的接口界面,主要包括主窗口、菜单拉杆、下拉菜单和绘图基的创建以及模型数据输入和图形的绘制。有限元法地震正演模拟系统的总体结构由四个层次的内容组成,其主要功能是:输入模型参数和排列参数(包括激发、接收参数);进行有限元法地震正演模拟计算;修改模型参数并重新进行计算。 相似文献
598.
599.
给出了正交曲线坐标系下平面二维非恒定动床紊流模型基本方程组,即水流运动方程及潮汐水流不平衡输沙方程。对计算中的有关问题提出了处理方法,如基本资料及代表潮过程选取、糙率的确定、悬沙粒径及沉速、挟沙能力恢复饱和系数及河床冲淤判别条件等。以甬江口为例,计算了镇海弯道至大游山口门约5km河段潮汐水流潮位及流速过程、丁坝作用下的回流域及疏浚与整治相结合的河床变形,计算结果与野外资料吻合良好。在此基础上,计算了宁波大桥桥墩作用下的水流结构变化及对镇海港航道的冲淤影响。 相似文献
600.
John Gunn 《地球表面变化过程与地形》1981,6(6):595-597
Recent work by Láng (1977) on solutional erosion rates in limestone drainage basins in relation to rainfall contains serious errors and has a questionable logical basis. Although much sounder, Smith and Atkinson's (1976) work on erosion rates in relation to runoff also requires modification as it greatly overestimates erosion rates in two areas of New Zealand. Greater resolution could probably be obtained by relating autogenic runoff to the rate of solution by autogenic waters and by computing separate relationships for areas where solution takes place under open and closed system equilibrium conditions. These factors should be taken into account in the experimental design of future studies. 相似文献