Reliability-Based Geotechnical Design

基于可靠性的岩土工程设计

• 批准号: RGPIN-2016-05433
• 负责人: Fenton, Gordon
• 金额: $ 1.97万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=650621
• 关键词: Reliability; Based; Geotechnical; Design

The most recent edition of the Canadian Highway Bridge Design Code (CHBDC 2014) includes substantial changes in geotechnical design philosophy. The code now includes resistance factors that depend on the level of site understanding, as well as a new consequence factor that depends on failure consequence severity.***Drawing from research performed over many years, the applicant calibrated the resistance and consequence factors appearing in the 2014 CHBDC to achieve target reliability levels. However, much research is still required to refine these factors and to extend them to cover other limit states. To this end, this research proposal will address the following two main tasks:***1) One of the major identified goals for the next edition of the CHBDC is to develop geotechnical seismic design code provisions to include in the geotechnical design chapter. To accomplish this goal, design load and resistance factors need to be determined that properly target the desired reliability index for extreme event seismic limit states in geotechnical systems. The research will start by looking at slope stability under seismic loading, where the slope is represented by a spatially variable random field. Failure probabilities as functions of ground parameter statistics and slope geometry will be estimated, conditioned on various levels of ground motion excitation. The results will then be combined using the total probability theorem to assess the reliability of various slope designs, given sample estimates of ground strength statistics. Design procedures and factors will be proposed for use in the CHBDC and the National Building Code of Canada (NBCC). The research will then be extended to a variety of other geotechnical problems, such as shallow foundations, deep foundations, and retaining structures.***2) When a structure is supported by multiple foundations, failure of the structure often requires the failure of more than a single foundation element - if so, the foundation system is said to have some redundancy. An important question that arises when foundation redundancy exists is what should the target reliability of individual foundation elements be in order to achieve a desired target system reliability? The goal of this research task is to investigate the relationship between geotechnical redundancy and system reliability so that informed design decisions can be made about individual foundation elements.***Both of the above research tasks are excellent opportunities for the training of highly qualified personnel, especially since these personnel will directly see the need, application, and implementation of their research results in major Canadian design codes of practice.**

最新版本的加拿大公路桥梁设计规范 (CHBDC 2014) 对岩土设计理念进行了重大改变。该规范现在包括取决于现场理解水平的阻力因素，以及取决于故障后果严重程度的新后果因素。***根据多年来进行的研究，申请人校准了出现在中的阻力和后果因素。 2014 年 CHBDC 达到目标可靠性水平。然而，仍需要大量研究来完善这些因素并将其扩展到其他极限状态。为此，本研究提案将解决以下两个主要任务：***1) 下一版 CHBDC 的主要确定目标之一是制定岩土工程抗震设计规范条款，以纳入岩土工程设计章节。为了实现这一目标，需要确定设计载荷和阻力系数，以正确定位岩土系统中极端事件地震极限状态所需的可靠性指数。该研究将从研究地震荷载下的边坡稳定性开始，其中边坡由空间变化的随机场表示。将根据不同水平的地面运动激励来估计作为地面参数统计和斜坡几何形状的函数的失效概率。然后，根据地面强度统计数据的样本估计，使用总概率定理将结果结合起来，以评估各种斜坡设计的可靠性。将提议在 CHBDC 和加拿大国家建筑规范 (NBCC) 中使用的设计程序和因素。然后，该研究将扩展到各种其他岩土工程问题，例如浅基础、深基础和挡土结构。***2) 当结构由多个基础支撑时，结构的破坏通常需要更多基础的破坏。不是单个基础元件 - 如果是这样，则基础系统据说具有一些冗余。当存在基础冗余时出现的一个重要问题是，为了实现所需的目标系统可靠性，各个基础元件的目标可靠性应该是多少？这项研究任务的目标是调查岩土冗余和系统可靠性之间的关系，以便就各个基础元件做出明智的设计决策。***上述两项研究任务都是培训高素质人才的绝佳机会，特别是因为这些人员将直接看到他们的研究成果在加拿大主要设计实践规范中的需求、应用和实施。**