对于以盾构方式修建的地铁，其隧道管片是主要的受力构件。在以热辐射为主的火灾中，会形成比较均匀的温度场。由于管片受热均匀，整周管片内部将产生均匀的热力荷载，加之地应力荷载使其应力分布更为复杂。使用FLAC3D模拟在以热辐射为主的火灾中，管片应力分布和变化特征。根据温度不同材料性质不同的客观事实，在模拟过程中随温度升高实时调整材料参数，使模拟结果更加准确。分析结果表明：最大水平压力上升比较快，1000℃时其比最大竖向压力大30％。最大值的位置分别对称于经过隧道轴线的水平和竖直面。总位移在400℃后明显增加，最大位移一般在隧道左右两侧。%The tunnel segment of the shield construction subway is the main bearing structure .In the fire with the thermal radiation primarily , the formed temperature field is relatively uniform field .In this field, the circle seg-ments will produce uniform thermal load , as well as the ground stress load , which make the stress distribution more complex .According to tunnel construction practice , in the uniform temperature field with linear increase process of temperature, FLAC3D was used to simulate the stress distribution and deformation characteristics of the segment . According to the fact that material properties were different in the different temperature , the parameters were adjus-ted real-timely, in the simulation process with temperature rising , so that the simulation results could be more accu-rate.The results showed that: the maximum horizontal pressure rises faster , it is larger than the largest vertical pressure 30%in 1000℃.The location of the maximum is symmetry of surfaces that across respectively horizontal and vertical axis .In 400℃, total displacement significantly increases , and the maximal displacements are in both sides of tunnel commonly .
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