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.**

加拿大高速公路桥设计代码（CHBDC 2014）的最新版本包括岩土设计理念的实质性变化。该法规现在包括取决于现场理解水平的电阻因素，以及取决于失败后果​​严重程度的新结果因素。***从研究进行的研究中，申请人校准了2014年CHBDC中出现的阻力和后果因素，以达到目标可靠性水平。但是，仍然需要进行大量研究才能完善这些因素并将其扩展以涵盖其他极限状态。为此，该研究建议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开发岩土技术设计代码规定，以包括在岩土技术设计章节中。为了实现这一目标，需要确定设计负载和阻力因素，以适当针对岩土技术中极端事件地震限制状态的所需可靠性指数。该研究将从地震载荷下的斜率稳定性开始，其中斜率由空间可变的随机场表示。将估计以各种水平的地面运动激发为条件，将估计故障概率作为地面参数统计和斜率几何形状的功能。然后，考虑到地面强度统计的样本估计值，将使用总概率定理将结果合并，以评估各种坡度设计的可靠性。设计程序和因素将用于CHBDC和《加拿大国家建筑法典》（NBCC）。然后，该研究将扩展到其他各种岩土技术问题，例如浅基础，深层基础和保留结构。*** 2）当结构受到多个基础支持的结构，该结构的失败通常需要多个基础元素的失败 - 如果是这样，则据说基础系统具有一些冗余。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，各个基础要素的目标可靠性应该是什么？这项研究任务的目的是调查岩土的冗余与系统可靠性之间的关系，以便可以就个人基础元素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员的绝佳机会，尤其是因为这些人员将直接看到其在加拿大加拿大设计的实践编码中的需求，应用和实施。