Design of Geotechnical Infrastructure Using the Mechanics of Unsaturated Soils

利用非饱和土力学进行岩土基础设施设计

• 批准号: RGPIN-2015-05277
• 负责人: Vanapalli, Sai
• 金额: $ 1.82万
• 依托单位: University of Ottawa
• 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=667563
• 关键词: Design; Geotechnical; Infrastructure; Using; Mechanics

Significant economic benefits can be achieved for Canada by designing geotechnical infrastructure based on the mechanics of unsaturated soils, taking account of the influence of suction. However, such design approaches are limited in conventional practice. This is because of the inherent complexity of mechanics of unsaturated soils theory, as well as the time-consuming experimental studies that need elaborate testing equipment and trained personnel. For these reasons, it is important to propose design approaches extending the mechanics of unsaturated soils that are simple for implementing in practice. To address this urgent need, the applicant, through this proposal, will focus on three research themes of significant interest. ***(i) Research Theme I: Design of pavements for highways and railways; ***Pavement design methods as per Mechanistic-Empirical Pavement Design Guide are categorized as Level 1, 2 or 3 to meet the various design standards required for pavements. Level 1 methods are expensive and cumbersome, and need elaborate testing facilities, while Level 3 methods are empirical in nature and have limitations. A two-step approach will be proposed as a Level 2 method for meeting the pavements design standards of Canada. This approach can also be applied for railways, taking into consideration the relevant load and design factors.***(ii) Research Theme II: Estimation of the variation of heave and swelling pressure of expansive soil with respect to suction; ***Swelling pressure associated with expansive soils is influenced by soil suction reduction induced by wetting. Ground heave in both lateral and vertical directions has significant effect on the performance of geotechnical infrastructure due to the influence of swelling pressure. A simple technique will be proposed based on the conventional soil properties for estimation of swelling pressure and 1-D heave. Such a technique will be of interest because it can be used for reliable design of both shallow and deep foundations constructed with or within expansive soils. ***(iii) Research Theme III: The effect of swelling on the stability of slopes in expansive soils; ***The proposed research will develop a framework of numerical modeling tools to reliably design slopes in expansive soils, which is one of the most challenging geotechnical problems. This framework can also be extended with some modifications for other problematic soils, such as the sensitive clays of eastern Canada.***The applicant's long-term vision through this proposal is to contribute to the design of sustainable geotechnical infrastructure in unsaturated soils and other problematic soils such as expansive and sensitive soils of Canada. The goal is to provide simple, yet reliable, solutions that can be used to implement the mechanics of unsaturated soils in practice with a greater degree of confidence, and simultaneously contribute to the Canadian economy.**

通过基于非饱和土力学并考虑吸力的影响来设计岩土基础设施，可以为加拿大带来显著的经济效益。然而，这种设计方法在常规实践中受到限制。这是因为非饱和土力学理论本身的复杂性，以及实验研究的耗时性，需要复杂的测试设备和训练有素的人员。由于这些原因，重要的是要提出设计方法，扩展非饱和土的力学，在实践中实施简单。为了满足这一迫切需求，申请人将通过本提案重点关注三个重要的研究主题。 * （i）研究主题一：公路和铁路路面设计; * 根据《机械-经验路面设计指南》，路面设计方法分为1级、2级或3级，以满足路面所需的各种设计标准。第一级方法既昂贵又繁琐，需要复杂的测试设施，而第三级方法本质上是经验性的，有局限性。将提出一种两步法作为满足加拿大路面设计标准的2级方法。考虑到相关的荷载和设计因素，这种方法也可适用于铁路。(ii)研究主题二：膨胀土的升沉和膨胀压力随吸力变化的估计; * 膨胀土的膨胀压力受土壤润湿引起的吸力减小的影响。由于膨胀压力的影响，地基在横向和竖向上的隆起对岩土基础结构的性能都有显著的影响。一个简单的技术，将提出基于传统的土壤性质的膨胀压力和一维隆起估计。这种技术将是有趣的，因为它可以用于可靠的设计，浅和深的基础建设与膨胀土或内。 * （iii）研究主题III：膨胀对膨胀土斜坡稳定性的影响; * 拟议的研究将开发一个数值建模工具框架，以可靠地设计膨胀土斜坡，这是最具挑战性的岩土工程问题之一。这个框架也可以扩展到其他有问题的土壤，如加拿大东部的敏感粘土。申请人通过本提案的长期愿景是促进在不饱和土壤和其他有问题的土壤（如加拿大的膨胀性和敏感性土壤）中设计可持续的岩土基础设施。我们的目标是提供简单而可靠的解决方案，可用于在实践中更有信心地实施非饱和土力学，同时为加拿大经济做出贡献。