PARALLEL STOCHASTIC ANALYSIS FOR GEO-ENGINEERING

地球工程并行随机分析

• 批准号: EP/D037247/1
• 负责人: Michael Hicks
• 金额: $ 12.91万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FD037247%2F1
• 关键词: PARALLEL; STOCHASTIC; ANALYSIS; GEO; ENGINEERING

[In what follows: 1. Reliability is the probability that failure will not occur; 2. A characteristic value is that single value of a material property which, when used in a deterministic analysis, will give the same response as a stochastic analysis for a given level of reliability; 3. A reduction factor is that factor (from 0.0 to 1.0) by which the mean property value is scaled to give the characteristic value.]The proposed research concentrates on the fact that natural materials are variable and that representation of this variability appears crucial to getting a realistic understanding of certain geotechnical and geo-environmental problems. A specific problem is chosen for illustrative purposes. The investigation requires one Research Associate, who will focus on: (a) converting existing finite element codes from serial to parallel environments; (b) using these optimised codes to investigate the influence of heterogeneity on 3-D slope stability. It involves a total cost of 91k plus notional service costs of 104k, and is divided into two parts:1. The stability of cut slopes in clay. This simple (total stress) application will determine reliability-based reduction factors for undrained shear strength, from which reliability-based characteristic values may be derived. Of particular interest will be the comparison between reduction factors based on 2-D and 3-D analyses: i.e. how conservative is the 2-D approach, and what economies are to be gained through basing reduction factors on the true 3-D response? The study will also investigate the influence of heterogeneity on the evolution of failure mechanisms and on the volumes of soil involved in potential slides.2. The stability of underwater sandfill slopes (using a coupled effective stress approach). The first stage will be to compare 2-D and 3-D responses for long slopes. (Hence, the remit will be similar to that for cut slopes in clay, except that the derived reduction factors will be for soil friction angle.) The second stage will consider the Nerlerk underwater berm. This structure was designed to form part of a bottom-founded oil exploration platform in the Canadian Beaufort Sea, but failed during construction (at a height of 26 m) due to static liquefaction. This complicated 3-D application will simulate the construction of the berm, and will result in predictions of the probability of failure, the height of the berm at which failure occurs, and the geometries and volumes of potential slides. (Note that there are detailed field measurements available for comparison.) Significantly, it will provide a benchmark against which previous, current and future 2-D investigations may be properly quantified.The proposed research will demonstrate a new and more meaningful approach to representing geo-structural response, with the definition of stability (reliability) now reflecting the variable nature of the material which is being analysed. Geo-environmental applications are seen as a particular area in which parallel stochastic analysis will flourish.

【内容如下： 1、可靠性是指不发生故障的概率； 2. 特征值是材料属性的单个值，当用于确定性分析时，对于给定的可靠性水平将给出与随机分析相同的响应； 3. 缩减因子是指将平均属性值缩放以给出特征值的因子（从 0.0 到 1.0）。]拟议的研究集中于天然材料是可变的这一事实，并且这种可变性的表示对于获得对某些岩土工程和地质环境问题的现实理解至关重要。选择一个特定问题是为了说明目的。该调查需要一名研究助理，他将专注于：（a）将现有的有限元代码从串行环境转换为并行环境； (b) 使用这些优化的代码来研究异质性对 3-D 边坡稳定性的影响。总成本91k，加上名义服务成本104k，分为两部分： 1．粘土路堑边坡的稳定性。这个简单的（总应力）应用将确定不排水剪切强度的基于可靠性的折减系数，从中可以导出基于可靠性的特征值。特别令人感兴趣的是基于 2-D 和 3-D 分析的折减系数之间的比较：即 2-D 方法的保守程度如何，以及通过基于真实 3-D 响应的折减系数可以获得哪些经济效益？该研究还将调查异质性对破坏机制演变以及潜在滑坡涉及的土壤体积的影响。2．水下填砂斜坡的稳定性（使用耦合有效应力方法）。第一阶段将比较长斜坡的 2D 和 3D 响应。 （因此，其范围与粘土切坡的范围类似，只是导出的折减系数适用于土壤摩擦角。）第二阶段将考虑 Nelerk 水下护堤。该结构原本是加拿大波弗特海底部石油勘探平台的一部分，但在施工过程中（高度为 26 m）由于静态液化而失败。这个复杂的 3D 应用程序将模拟护堤的施工，并预测故障概率、发生故障的护堤高度以及潜在滑坡的几何形状和体积。 （请注意，有详细的现场测量可供比较。）值得注意的是，它将提供一个基准，可以根据该基准正确量化以前、当前和未来的二维调查。拟议的研究将展示一种新的、更有意义的方法来表示地质结构响应，稳定性（可靠性）的定义现在反映了正在分析的材料的可变性质。地理环境应用被视为并行随机分析将蓬勃发展的特定领域。