Response of saturated soil to the intense heat of tunnel fires

饱和土壤对隧道火灾高温的响应

• 批准号: 0331332
• 负责人: Deborah Goodings
• 金额: $ 9.9万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0331332&HistoricalAwards=false
• 关键词: Response; saturated; soil; intense; heat

The sensitivity of structures to the effect of fire is well established and was stunningly demonstrated in the World Trade Center collapse of 9/11. Fires in underground structures are not uncommon, and appear to be increasing in frequency and severity. In prolonged tunnel fires, the temperature of the adjacent soil can rise as much as 400C or more. These high temperatures and associated temperature gradients in the soil are expected to impact the stability of the entire underground structure. The specific objective of this research program is to examine the response of saturated soil to temperature gradients associated with severe tunnel fires.This exploratory experimental research will address the system response of saturated soil subjected to prolonged, intense temperatures characteristic of public access rail and highway tunnel fires. It is supported under the Small Grants for Exploratory Research program. A physical model will be constructed that represents a simple one-dimensional cylindrical core from a section of the tunnel lining and the saturated soil above it. This model will be subjected to the fire loads expected in tunnel fires. It will be instrumented, and changes in the mechanical properties of the soil measured. This simple approach will provide a preliminary view of the temperature distribution, the thermally induced movement of water, vaporization of pore fluid, soil movement due to consolidation and to other pore fluid behavior, and changes in soil properties in response to representative insitu heat, fluid pressure, and surcharge conditions. More sophisticated model investigations to be initiated subsequent to this study will be based on these preliminary experimental results.From a technical point of view, this basic research ultimately will contribute to public safety through improved original design and remedial design of underground civil engineering structures that may be subject to intense and prolonged fire. In addition, it will generate a scientific discussion between distinct engineering disciplines: Geotechnical Engineering and Fire Protection Engineering.

结构对火灾影响的敏感性已经得到了充分的证实，并在9/11世贸中心倒塌中得到了惊人的证明。 地下建筑火灾并不罕见，而且似乎在频率和严重程度上都在增加。 在长时间的隧道火灾中，邻近土壤的温度可以上升400摄氏度或更高。 预计土壤中的这些高温和相关温度梯度将影响整个地下结构的稳定性。 本研究项目的具体目标是研究饱和土壤对严重隧道火灾相关温度梯度的响应，这一探索性实验研究将解决饱和土壤对公共通道铁路和公路隧道火灾的长期高温特性的系统响应。 它得到了探索性研究小额赠款计划的支持。 将建造一个物理模型，该模型代表一个简单的一维圆柱形核心，该核心来自隧道衬砌的一部分及其上方的饱和土壤。该模型将承受隧道火灾中预期的火灾荷载。 它将被安装仪器，并测量土壤机械特性的变化。 这种简单的方法将提供一个初步的看法，温度分布，热引起的水的运动，孔隙流体的蒸发，土壤运动由于固结和其他孔隙流体的行为，并在土壤性质的变化，在代表性的原位热，流体压力，超载条件。 根据这些初步的实验结果，将在本研究之后开展更复杂的模型研究。从技术角度来看，这项基础研究最终将通过改进可能遭受强烈和长期火灾的地下土木工程结构的原始设计和补救设计，为公共安全做出贡献。 此外，它将在不同的工程学科之间产生科学讨论：岩土工程和消防工程。