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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613451
• 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.

通过根据非饱和土力学原理设计土工基础设施，并考虑吸力的影响，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是有限的。这是因为非饱和土力学理论的内在复杂性，以及耗时的实验研究，需要复杂的测试设备和训练有素的人员。出于这些原因，提出易于在实践中实施的扩展非饱和土力学的设计方法是很重要的。为了满足这一迫切需要，申请者将通过这项提案，重点关注三个重要的研究主题。 (1)研究主题一：公路和铁路人行道的设计； 根据《力学-经验路面设计指南》，路面设计方法分为1级、2级或3级，以满足各种路面设计标准。1级方法昂贵且繁琐，需要复杂的测试设施，而3级方法本质上是经验性的，有局限性。将提出一种两步法，作为满足加拿大人行道设计标准的第二级方法。考虑到相关的荷载和设计因素，这种方法也可以应用于铁路。 (2)研究主题二：估计膨胀土的隆起和膨胀压力相对于吸力的变化； 膨胀土的膨胀压力受湿润引起的土体吸力减小的影响。由于膨胀压力的影响，侧向和竖向地面隆起对岩土基础设施的使用性能都有显著的影响。在传统土性的基础上，提出了一种估算膨胀压力和一维隆起的简单方法。这种技术将是有意义的，因为它可以用于用膨胀土建造或在膨胀土中建造的浅基础和深基础的可靠设计。 (3)研究主题III：膨胀土中膨胀对斜坡稳定性的影响； 这项拟议的研究将开发一个数值模拟工具的框架，以可靠地设计膨胀土中的斜坡，这是最具挑战性的岩土问题之一。这个框架还可以扩展到其他有问题的土壤，例如加拿大东部的敏感粘土。 申请人通过这项提案的长期愿景是促进在非饱和土壤和其他问题土壤(如加拿大的膨胀土壤和敏感土壤)中设计可持续的岩土基础设施。目标是提供简单而可靠的解决方案，这些解决方案可用于在实践中更有信心地实施非饱和土壤的力学，同时为加拿大经济做出贡献。