中文摘要：

研究了混凝土结构最短路径射线追踪方法．该方法采用二阶段射线追踪，第一阶段初选射线路径，第二阶段根据Fermat原理，采用一个适合于水平（垂直）层状界面情况下的一阶近似公式计算反射或折射修正点，然后从任意给定的初始路径出发进行逐段迭代计算，对初选射线路径进行校正分析确定最终射线路径．结合损伤混凝土梁试验，探讨了损伤混凝土叠加偏移处理时射线追踪模型正演技术的作用，用c^＋＋语言编制了程序，并设定了含有缺陷的二维速度模型来验证，结果表明，该方法追踪速度快，追踪到的路径很接近实际．

英文摘要：

The shortest path of ray tracing method in the concrete structure is studied in the paper. This method includes two stages, the first is to choose the primary ray path, and the second to confirm the final ray path by correcting the primary path which has already been chosen on the first stage. The detailed iterative means basing on Fermat＇s principle , a one-order approximate formula , which is suitable to horizontal（vertical） interfaces is used to compute refraction（reflection） point first ,then a segmental iterative account will be carried on beginning with any given initial ray path. Combined with the blemished concrete beam experiment, this paper discussed the function of ray tracing model positive method by using the stack migration Imaging Technology. A program is compiled with C＋＋, in which a velocity planar model including vice was input to validate the method. The result indicates that the tracing speed is fast and the path which is traced by this method is very close to reality.