随着地铁工程规模的不断扩大，双岛式地铁车站凭借着内部空间大、可容纳客流量多等优势得到广泛建设应用。相比于标准车站，双岛式地铁车站火灾面临烟气蔓延范围广、控制难度大等问题，对人员安全疏散造成极大影响。因此，开展双岛式地铁车站火灾烟气扩散规律及通风控制方法研究，对于提升地铁车站火灾防治水平和保障人民生命财产安全具有重要意义。结合文献调研、工程调研、理论分析、模型实验、全尺寸实验和数值模拟等方法，从双岛式地铁车站火灾烟气输运规律、双岛式地铁车站站台火灾烟气往站厅扩散的临界控制理论、双岛式地铁车站火灾烟气通风控制模式三个方面开展研究，具体如下：在双岛式地铁车站火灾烟气输运规律研究方面，首先以单个岛式站台为基础，研究不同火灾场景和通风条件下的顶棚温度分布、垂直温度分布及烟气层高度分布特性；然后将火灾场景扩展至双岛式车站宽大空间内，引入火源与侧壁的横向距离和纵向距离因素，提出了顶棚温度分布的径向扩散和一维扩散模型；最后，针对双岛式地铁站台火灾烟气从楼梯口往站厅溢流现象，分析火源功率、火源位置、屏蔽门形式及挡烟垂壁深度对站厅溢流温度的影响，并建立了楼梯口溢流中心线温度预测模型。在双岛式地铁站台火灾往站厅扩散的临界控制理论研究方面，以楼梯口火灾场景为例，建立了站台火灾烟气在公共站厅的扩散范围随通风量变化规律式，并以此得到临界通风量预测模型；另外，考虑火源功率、火源位置、挡烟垂壁深度、楼梯朝向及数量等因素的影响，提出了挡烟垂壁下方及楼梯开口处临界风速模型，并利用楼梯开口处临界风速推导出车站临界通风量预测模型。在双岛式地铁车站火灾烟气通风控制模式研究方面，通过分析温度、CO浓度、能见度、可用安全疏散时间等参数，针对全封闭式屏蔽门的情况，分别提出了站台中部火灾和一侧火灾场景下隧道风机与屏蔽门系统的联动通风模式；针对非全封闭式屏蔽门的情况，考虑站台中部火灾、中间隧道车内火灾、一侧隧道车内火灾、中间隧道车厢火灾、一侧隧道车厢火灾等场景，提出了双岛式地铁车站各区域通风排烟系统的协同控烟策略。
As the continuous expansion of subway projects, the double-island subway station has been widely constructed and applied due to its advantages, such as large internal space and large passenger capacity. Compared to the standard station, fire accidents in double-island subway stations would cause a wider smoke spread range and more difficult control measure, which greatly affect the safe evacuation of personnel. Therefore, it is necessary to conduct research on smoke diffusion law and ventilation control method in the double-island subway station, which is of great significance for improving the level of fire prevention and control in subway stations and ensuring the safety of people‘s lives and property.Various methods are combined in this study, such as literature research, engineering research, theoretical analysis, model experiments, full-scale experiments, and numerical simulation. Three contents have been conducted: the law of fire smoke transportation in the double-island subway station, the critical control theory of smoke diffusion from the platform to the station hall, and the smoke ventilation mode in the double-island subway station. The details are as follows:In terms of fire smoke transportation in the double island subway station, firstly, the ceiling temperature distribution, vertical temperature distribution, and smoke layer height under different fire scenarios and ventilation conditions are studied in an island platform; Then, the fire scenario is extended to the wide space of the double-island station, and the radial and one-dimensional prediction models for the ceiling temperature are proposed, introducing the factors of the lateral and longitudinal distance between the fire source and the side wall; Finally, aiming at the smoke overflow from the platform to the station hall through the stairway in a double-island subway station, the effects of fire source power, fire source location, platform screen doors (PSD) and ceiling screen on the smoke temperature in the station hall are analyzed, and a prediction model for the overflow centerline temperature is established.In terms of the critical control theory for the smoke diffusion from platform into the station hall in a double-island subway, taking the fire source at the stair entrance as an example, the relationship between the diffusion range in the station hall and the ventilation volume is analyzed, and a prediction model for the critical ventilation volume is obtained; In addition, considering the influences of fire source power, fire source location, ceiling screen depth, and the orientation and number of stair, the prediction models for critical velocity below the ceiling screen and at the stair opening are proposed, and a prediction model for the critical ventilation volume is derived using the critical velocity at the stair opening.In terms of fire-induced smoke control modes in a double-island subway station: based on the analysis of temperature, CO concentration, visibility, available safety egress time and so on, for the fully enclosed PSD, the optimal linkage modes for tunnel fans and PSD systems under a fire in the middle or one side of the platform are proposed respectively; for non-fully enclosed PSD, considering the scenarios of platform fire, fire inside the carriage in the middle tunnel, fire inside the carriage in the side tunnel, carriage fire in the middle tunnel, carriage fire in the side tunnel, collaborative smoke control strategies for each area of the double-island subway station are proposed.
