Influence of gassy soils and gas hydrates on submarine slope failure

含气土壤和天然气水合物对海底边坡破坏的影响

• 批准号: 238267-2006
• 负责人: Grozic, Jocelyn
• 金额: $ 1.7万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=393843
• 关键词: Influence; gassy; soils; gas; hydrates

Offshore geohazards impact the economic development and safe operation of marine infrastructure.  Landslides occurring on the ocean floor are a common geohazard that have considerable potential for damage and loss of life; yet, the triggering and evolution of submarine slides is not well understood.  This is particularly true when examining the effects of gas in soils.  Gas, in bubble or hydrate form, has been circumstantially and theoretically linked to many submarine slope failures.  However, it remains a major challenge to integrate the role of gas into the quantitative analysis and prediction of submarine slope failures. This research is aimed at obtaining an integrated understanding of the significance of gas in marine soils using a combined experimental and theoretical approach.  Experimental studies will investigate the fundamental behaviour of soil containing gas and gas hydrates using customized geotechnical testing equipment located in two new facilities at the University of Calgary.  Constitutive models, verified with the results of the laboratory program, will be developed to describe the theoretical behavioural changes of the soil during hydrate dissociation and gassy soil unloading.  The constitutive models will then be incorporated into stability assessments to quantitatively analyze the stability of submarine slopes.  Finally, the results from all phases will be synthesized to develop recommendations regarding submarine slope stability, with particular emphasis on the governing parameters such as gas content, hydrate content, soil conditions, topography, and oceanographic data.  These recommendations will ultimately result in the development of guidelines that will enable the risk of damage to existing infrastructure and coastal developments to be evaluated and facilitate safer and more cost-effective designs of future offshore developments.  As the search for resources takes us into deeper water, remote regions, and unfamiliar territory, and the expanding global population continues increasing pressure to already burgeoning coastal areas, improved knowledge of the seabed conditions is of critical importance.

近海地质灾害影响经济发展和海洋基础设施的安全运行。发生在海底的滑坡是一种常见的地质灾害，具有相当大的破坏和生命损失的潜力；然而，海底滑坡的触发和演化还没有被很好地了解。尤其是在考察土壤中气体的影响时。天然气以气泡或水合物的形式存在，在环境和理论上与许多海底斜坡破坏有关。然而，将天然气的作用整合到海底斜坡失效的定量分析和预测中仍然是一个重大挑战。这项研究的目的是通过实验和理论相结合的方法，对海洋土壤中气体的意义有一个完整的认识。实验研究将使用位于卡尔加里大学两个新设施中的定制岩土测试设备来调查含有气体和气体水合物的土壤的基本性质。最后，将建立本构模型，并与实验室计划的结果进行验证，以描述土壤在水合物分解和含气土壤卸载过程中的理论行为变化。然后，本构模型将被纳入稳定性评估中，以定量地分析海底斜坡的稳定性。最后，将所有阶段的结果综合起来，以制定关于海底斜坡稳定性的建议。特别强调控制参数，如气体含量、水合物含量、土壤条件、地形和海洋数据。这些建议最终将导致制定指导方针，使现有基础设施和沿海开发的破坏风险得以评估，并促进未来近海开发的更安全、更具成本效益的设计。随着对资源的搜索将我们带到更深的水域、偏远地区和陌生的领土，以及不断增长的全球人口继续对已经迅速增长的沿海地区施加越来越大的压力，提高对海底条件的了解至关重要。