In fire, the slabs not only act as the role of bearing, but also assum the role of cutting off fire, which are the most serious destroyed elments .

火灾中，钢筋混凝土板在起承重和防火隔断作用的同时，也是受火面最大、损伤最严重的构件之一。

Then, with some approximation to the wave front section, the forward modeling can be achieved through the ray tracing method based on the minimum traveling time and the shortest traveling trace assum.

然后，对波阵面作一近似，在此基础上，用最小走时最短路径射线追踪法完成正演。