气体爆炸危险源致灾能量多重性的物理机制及灾变过程

Distinct from the condensed explosion hazard source, energy release of gas explosion hazard source is dependent on the interaction of explosion and structure, and represents the multiplicity. This character restricts accurate prediction and effective prevention and control of gas explosion accidents seriously. By the gas explosion and its disaster processes in typical buildings as the research object, based on the basic principle of gas explosion, the project studies the physical mechanism of multiplicity of the disaster-causing energy released by gas explosion hazard source and catastrophe process. Firstly, based on comprehensive consideration of various influencing factors, such as constraints, environments and the distribution of hazard material, the project importantly studies the interaction mechanism of the explosion process and the constraint structures, and the quantitative influencing laws of structure damage and failure on the evolution of the explosion flow field and the release of the energy, and explores real dynamic response process of local building structures under the direct action of gas explosion and its damage mechanism. On this basis, it further studies the multiple evolution mechanism of disaster-causing energy released by gas explosion hazard source along time and space, explores the quantitative spatiotemporal relationship between the energy and the main influencing factors, and builds a quantitative evaluation method of the disaster-causing energy. The expected outcome of the project helps to cast off the excessive dependence on condensed explosion theory and empirical model, and provides scientific theoretical basis and effective technical support for the disaster assessment of gas explosion hazard source and the design of building anti-explosion and strengthening.

与凝聚态爆炸危险源截然不同，气体爆炸危险源致灾能量的释放依赖于爆炸与结构的相互作用而表现为多重性，严重制约气体爆炸灾害的准确预报和事故防控。本项目以典型建筑结构内气体爆炸致灾过程为研究对象，基于气体爆炸基本原理，系统研究气体爆炸危险源致灾能量多重性的物理机制及灾变过程。首先，在全面考查约束、环境、危险源分布等多种影响因素的基础上，重点研究爆炸过程与约束结构的耦合作用机理，研究结构破坏失效对爆炸流场演化及能量释放的定量影响规律，探索局部建筑结构在气体爆炸直接作用下的真实动力响应过程及破坏机理；以此为基础，进一步探索气体爆炸危险源致灾能量沿时间和空间的多重性演化机制，探究致灾能量与主要影响因素的定量时空关系，构建致灾能量的定量评估方法。本项目预期成果有助于摆脱对凝聚态爆炸理论及经验模型的过分依赖，为气体爆炸危险源灾害评估与建筑物抗爆加固设计提供科学的理论依据和有效的技术支撑。

与凝聚态爆炸危险源截然不同，气体爆炸危险源致灾能量的释放依赖于爆炸与结构的相互作用而表现为多重性，严重制约气体爆炸灾害的准确预报和事故防控。本项目以典型建筑结构内气体爆炸致灾过程为研究对象，基于气体爆炸基本原理，系统研究气体爆炸危险源致灾能量多重性的物理机制及灾变过程。一是基于大尺度实验对比验证，建立了适合于约束泄爆条件下气体爆炸瞬态流场的数值方法，首次揭示了数值模拟过程中泄爆口外部计算域尺寸对约束泄爆效应的影响机制及规律，阐释了室内爆炸超压的振荡特征及本质原因，提出了泄爆口外部计算域的最优选取方案；二是阐明了气体爆炸流场与约束泄爆结构的耦合机理，揭示了约束结构、危险源、点火源等多种因素特征参数对爆炸能量多重性时空特征的影响机制及超压载荷“双峰”定量规律；三是初步阐明了气体爆炸作用下顶盖与侧墙的耦合泄爆机制，给出了顶部泄爆参数的选取建议；四是证实了“载荷-响应”两步数值方法在细致描述气体爆炸和结构响应全过程方面的有效性；五是基于多种影响因素构建了基于爆炸强度的气体内爆炸致灾能量定量评估模型，实现了爆炸灾害快速、准确评估。研究成果有助于摆脱对凝聚态爆炸理论及经验模型的过分依懒，对此类事故的事前预测和事后评估具有现实指导意义，对气体爆炸安全理论的进一步深化提供了理论依据。