结合渝（重庆）合（合川）高速公路西山坪隧道新奥法施工监测实践，分析了初期支护条件下隧道左线穿煤及采空区（LK35+360～LK35+560）围岩的变形特征，并对穿煤及采空区围岩的位移和应力特性进行了施工动态有限元数值模拟研究，验证了位移监测资料的正确性。为制定采空区处理措施和优化后期支护方案提供了信息。

A new CNC (Computerized Numerical Control) controlled water-cutter system was constructed and an experimental study on the machining of natural rock materials by using this system was conducted. The system has many advantages, such as long available stand-off distance, low specific energy consumption, high cutting efficiency, low pump pressure, low cost, and long life-span to machine various natural rock materials rock materials to any 2-dimentional curves, which are difficult or impossible to machine by using other traditional tools.

The jet position has a important influence on cutting process when water jet assists bit cutting rocks. In this paper the test for the effect of jet position on drag bit cutting process is described. The experimental methods, instrumentation and procedure are conducted. Four different jet positions were investigated in the test. The range of diameter of nozzles used is from 0.5 mm to 1.0 mm. The influence of jet position on rock chips formed ahead of bit is discussed. The effect of cut depth, bit velocity on bit force reductions is analyzed. The effectiveness of jet energy is examined for all kind of jet positions. And some important conclusions are given in the end of this paper. One of the most interesting results is that the water jet has the largest effect on drag bit cutting process when it is directed towards the center beneath the bit.

本文讨论了用于水介千周的中直径高压机械回转密封的结构和工作原理，试验分析了密封环材质的结构对密封性能的影响。研究表明。MC尼尼龙密封环寿命长。泄漏量小、性能稳定，适用于水介质、大中直径等场合。

In this part of the paper, the test that three PDC drag bits with different rake angle were used to make linear cuts in two rock types is conducted. The experimental methods, instrumentations and process are described. In order to investigate the relationship between the wear and damage of PDC inserts and bit forces as well as the influence of moderate pressure water jets on the cutting process is analyzed. Towards the end of this part of the paper, the conclusion is given.