新奥法的产生和发展,是地下建筑物设计施工的一项创新与革命。新奥法具有进度快、投资少、施工安全和运行可靠等优点,但同时也出现了新的矛盾。例如,施工速度快,必然要缩短排炮的循环时间,循环时间的长短,除了取决于岩石性质、工作面上钻孔设备的质量 The emergence and development of the new Austrian law is an innovation and revolution in the design and construction of underground buildings. The new Austrian law has the advantages of fast progress, less investment, construction safety and reliable operation, but at the same time, new contradictions have emerged. For example, construction speed is bound to shorten the cycle time of the cannon, the length of the cycle time, in addition to depending on the rock properties, the quality of the drilling equipment on the face