Abstract:The structure and working principle of BWZ-250 pump foam booster are described and it can provide a pressure increase of 5. 0 MPa with satisfactory pump rate and volumeric efficiency upto 0. 9. It is reasonable and economical to carry out foam drilling with low pressure compressor. Good results have beenachieved in three mines.

Abstract:The horrizontal boring rig consists of a horrizontal drill, a hole opening machine and a powerpack with a combined mechanical and hydraulic driving. The trial of the prototype indicates good results. Therig can be used in trenchless case for installation of small diameter circular or non--circular single and group pipesin plastic formation.

Abstract:The shortcomings of present drill derrick dismantling and assmbling are pointed out with solutions proposed. A dismantling and assembling machine for four-leg drill derricks and a mechanically assembleddrill derrick have been developed, which are thought to the trend of the geologic drill derrick.

Abstract:Teh description is made of the generals of the vibro-sinking high-pressure grouting diaphragmwall completion technology and the equipment, as well as the DJ-60 vibro-sinking high--pressure grouting rig,construction process and application. The technicality and economics of the technology are briefly analysed.

Abstract:The history, drilling mechanism and advantages of drilling holes with DTH ramming and displacement are discussed. The thoeretical analysis is made based on the problems present with the method in anchor installation and two types of displacing bits have been designed.

Abstract:The designs, tools and construction status of prestressed anchor projects home and abroad areanalysed and summed up while the present problems and development trend are also pointed out.

Abstract:The properties and application scope of thePCBN cutting tools are described with emphasis on the production process of pure PCBN cutting tools including manufacture and insert of PCBN, as well as the edge grindingtechnique and geometry of the PCBN cutting tools. Whichare used in processing, continuous cutting and rough machining of quench-hardening steel, heat sprayed material andquench--hardening cast iron.

Abstract:On the basis of experiment results from rock fragmentation by slantly penetrated cutting toolsthe drilling process of large cutting element drill bits is analysed and the penetration rate formulae for large cutting element drill bits in the case of rotary drilling is also derived.

Abstract:The brief description is given of the positive ion polymer mud system. A preliminary study hasbeen conducted in slim-hole coal geologic drilling resulting in some perfect effects.

Abstract:The bits and integral steels with composite teeth are successfully developed. Based on the mechanical theory and put into market commercially. The rock drilling rate, service life and tungsten carbide toothavailability of the series of bits are obviously better than those of chip and button type bits.

Abstract:介绍了凿岩钻进自动化的重要性，阐述了钻进自动化的发展历程。分析了钻车自动化的发展现状，指出了自动钻车科研工作的不足以及未来的发展方向。