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为研究地铁车站在火灾发生过程中结构随温度升高的受力和变形情况,以某地铁站主体结构为对象进行研究。车站中火源产生的温场是由热对流和热辐射叠加而成的混合温场,为使模拟更加精确,根据材料性质随温度改变的情况对模型材料参数进行调整;模拟了温度在4℃~1000℃范围内车站结构的受力、变形特征。分析结果表明:相同温度下,火源位置3对应的监测点沉降量最大,位置2次之,位置1最小;火源位置1和位置2测点沉降基本发生在距火源中心±20m内,位置3在±40m内,从沉降量看温度在600℃~1000℃范围内结构有进入塑性阶段趋势;空间刚度越小,热应力释放的主要区域越集中;火源位置1的热应力释放区间距火源中心80m之外,位置2在±20m内,位置3在±10m内,从竖向应力看在800℃~900℃范围内结构有进入塑性阶段趋势。研究可为火灾过程中或灾后车站结构安全性评价提供依据。
In order to study the stress and deformation of the metro station with temperature rise during the fire, the main structure of a metro station is studied. The temperature field produced by the fire source in the station is a mixed temperature field formed by superposition of heat convection and heat radiation. To make the simulation more accurate, the parameters of the model material are adjusted according to the change of material properties with temperature. Stresses and deformations of station structure in the range of ~ 1000 ℃. The results show that at the same temperature, the monitoring point settlement corresponding to the location 3 of the fire source is the largest, the location 2 times is the smallest, and the location 1 is the smallest. The settlement of the fire source location 1 and the location 2 basically takes place within ± 20m from the center of the fire source, The position 3 is within ± 40m, and the temperature is within the range of 600 ℃ ~ 1000 ℃. The structure tends to enter the plastic phase. The smaller the space stiffness, the more concentrated the main areas of thermal stress release. The thermal stress release zone Pitch fire center 80m, the location 2 within ± 20m, the location 3 within ± 10m, from the vertical stress in the range of 800 ℃ ~ 900 ℃ structure into the plastic stage of the trend. The research can provide the basis for the safety assessment of the station structure during or after a fire.