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.

[In具体如下：1.可靠性是不发生故障的概率; 2.特征值是材料属性的单个值，当用于确定性分析时，将给出与给定可靠性水平的随机分析相同的响应; 3.折减系数是将平均属性值缩放以给出特征值的系数（从0.0到1.0）。]拟议的研究集中在这样一个事实，即天然材料是可变的，这种可变性的代表性似乎至关重要的某些岩土工程和地质环境问题得到现实的理解。为了说明的目的，选择了一个具体的问题。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调查异质性对三维边坡稳定性的影响。它涉及91 k的总成本加上104 k的名义服务成本，并分为两个部分：1。粘性土路堑边坡的稳定性。这种简单的（总应力）应用将确定不排水抗剪强度的可靠性折减系数，并由此导出可靠性特征值。特别令人感兴趣的是基于二维和三维分析的折减系数之间的比较：即二维方法有多保守，以及通过将折减系数建立在真实三维响应的基础上将获得哪些经济效益？该研究还将调查非均匀性对破坏机制的演变和潜在滑动所涉及的土壤体积的影响。水下填砂边坡的稳定性（耦合有效应力法）。第一阶段将比较长边坡的二维和三维响应。（因此，除了推导出的折减系数是针对土壤摩擦角外，其范围与粘土路堑边坡的范围相似。）第二阶段将考虑Nerlerk水下护堤。该结构设计用于构成加拿大博福特海海底石油勘探平台的一部分，但由于静态液化，在施工期间（26 m高度）失败。这个复杂的三维应用程序将模拟护堤的施工，并将导致预测故障的概率，发生故障的护堤高度，以及潜在滑坡的几何形状和体积。(Note有详细的实地测量可供比较）。值得注意的是，它将提供一个基准，对以前，当前和未来的2-D调查可能会适当quantitatives.The拟议的研究将展示一个新的和更有意义的方法来表示地质结构的反应，与稳定性（可靠性）的定义，现在反映了正在分析的材料的可变性质。地质环境应用被认为是一个特殊的领域，其中并行随机分析将蓬勃发展。