The Role of Antecedent Conditions in Sinkhole Formation and Collapse Mechanisms

先行条件在天坑形成和塌陷机制中的作用

• 批准号: 2132557
• 金额: --
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2132557
• 关键词: Role; Antecedent; Conditions; Sinkhole; Formation

AimsThe main aims of the proposed research are to:- Explore the geotechnical properties of materials susceptible to sinkhole formation. This includes determining which particular materials are likely to be weakened by long periods of dry weather followed by heavy rain, and which combinations of these conditions are likely to result in the greatest likelihood of sinkholes forming. Meeting this aim will improve understanding of the stability of these materials when supporting foundations over emerging cavities, and could facilitate the prediction of sinkholes in areas where land has already been developed, which could be used to prevent injury and potential loss of life. - Investigate the mechanisms involved in the development of different types of sinkhole, such as the softening and failure of historic chalk workings. An understanding of the physics involved in these failures could inform additions to building regulations and design codes for infrastructure and structures in areas susceptible to sinkholes. MethodIn order to meet the aims listed, the following research method is proposed:- A geotechnical desk study to identify suitable sites for sample extraction. This will be done using existing literature, as well as the BGS sinkhole database.- Samples of clay, chalk and other rocks will be taken from the selected locations at different times of the year, with technical support and drilling equipment to be provided by BGS. These samples will be used to determine a ground profile for the site.- The geotechnical properties of the samples, such as the relationship between water content and strength will be tested. This will be carried out in lab facilities provided by BGS. - Based on the geotechnical properties and ground profile of the site, scale models of typical sinkhole prone formations will be produced for testing in a centrifuge, to generate typical in-situ stresses. This will require the use of further samples or of synthetic soil material. The centrifuge is an existing facility at the University of Sheffield.- A technique for simulating aging effects of different antecedent conditions on the models will be developed. This may require new equipment such as drying and humidifying devices. The technique will be verified by comparison of artificially aged rocks with naturally weathered rocks. - Rock and soil models with different moisture contents, and ageing conditions will be produced. - These models will be tested in the centrifuge and their failure mechanisms studied and classified using image analysis techniques, such as particle image velocimetry, and calculated back analysis. - The relationship between water content, strength and ageing conditions will be analysed and the critical combination resulting in the most sinkholes determined.

AimsThe拟议的研究的主要目的是：-探索材料的岩土性能容易形成天坑。这包括确定哪些特定的材料可能会被长时间的干燥天气和大雨削弱，以及这些条件的组合可能会导致天坑形成的最大可能性。实现这一目标将提高对这些材料在支撑地基时的稳定性的理解，并有助于预测已经开发土地的地区的天坑，这可用于防止伤害和潜在的生命损失。- 调查不同类型的天坑的发展机制，如历史上的白垩工作的软化和失败。对这些故障所涉及的物理学的理解可以为易受天坑影响的地区的基础设施和结构的建筑法规和设计规范提供信息。方法为了满足所列的目标，提出了以下研究方法：-岩土案头研究，以确定合适的地点进行样品提取。这将使用现有的文献以及BGS天坑数据库来完成。粘土、白垩和其他岩石的样本将在一年中的不同时间从选定的地点采集，BGS将提供技术支持和钻探设备。这些样本将用于确定现场的地面剖面。将测试样品的岩土性质，例如含水量与强度之间的关系。这将在BGS提供的实验室设施中进行。- 根据场地的岩土特性和地面剖面，将制作典型易陷地层的比例模型，用于离心机测试，以产生典型的原地应力。这将需要使用更多的样品或合成土壤材料。离心机是谢菲尔德大学现有的设施。将开发一种模拟不同前期条件对模型的老化影响的技术。这可能需要新的设备，如干燥和干燥装置。该技术将通过人工老化岩石与自然风化岩石的比较来验证。- 将产生具有不同含水量和老化条件的岩石和土壤模型。- 这些模型将在离心机中进行测试，并使用图像分析技术（如粒子图像测速法和计算反分析）对其失效机理进行研究和分类。- 将分析含水量、强度和老化条件之间的关系，并确定导致最多天坑的临界组合。