Abstract:The structure, operating principle and the features of the fully telescopic retractable bit are described; the prospect of use of the tool in the continental scientific drilling of China and some problems present with it are analysed.

Abstract:GA side pressure gauge is described in terms of its basic structure, operating principle and testing with relevant caculating methods, and the representative results of it are analysed.

Abstract:The computorized numerical controlled rotary rheometer is an instrument which tests the mud rheological parameters with the computor intelligence. The description is made of the operating principle, performance index, features as well as the hardware and sensor design and the soft ware function design.

Abstract:The description is made of the partial cross section tunnelling machine in terms of the contents, criteria and specific requirements in the design of the layout, as well as the arrangement of each part and the determination of the general parameters including capacity, dimension, applicable cross sections, productivity, generality of the machine. It will provide some guidance for the proper design and use of the tunnelling machine.

Abstract:The hazardous rock mass of the Lianziya Cliff is outlined with the anchor hole drilling technology for the treatment presented, including the mounting of the drill on the overhead scaffold, prevention and measurement of the hole deviation, drilling in the broken zone and large fracture, as well as sealing of the fracture.

Abstract:The objectives of testing the bored pile, the types, the testing methods and the general specifications for pile testing are introduced. The test pile installation technique is described from the angle of all round quality management in four stages: planning, execution, inspection, and summary.

Abstract:Description is made of a new down hole tool used in soft ground-rolling device in terms of its basic operating principle and working process in bored pile foundation construction, its basic structure and the technical characteristics of various rolling devices.

Abstract:Most of the newly located holes for the exploration of the old mines are infilled between or lie behind two existing holes. In the light of this feature, the design method of the axis of the newly positioned hole is presented with the kicking off and deviation correction measures, resulting in good effect.

Abstract:Thickening characteristics is an important behaviour of cement slurry in the operation of geothermal well cementation. The thickening tests have been carried out under the simulated conditions of temperature and pressure. The appraisal has been made of seven kinds of retarders through high temperature retarding tests, the results show that Boric acid is an effective retarder for high temperature cement slurry, which is employed in regulating the consistency of two high temperature geothermal cement slurries.

Abstract:The experiments have been carried out to compare the application of Ni Co matrix diamond core bits to Ni Mn matrix diamond core bits. It is proved that Ni Mn matrix diamond core bits are suitable for drilling hard and broken rock, strong abrasive formation and soft hard alternate formation.

Abstract:Advances in tunnelling and underground engineering in China are briefly described, and the construction methods and auxiliary processes employed in tunnelling and underground engineering are introduced with some key problems to which attention should be paid during construction.

Abstract:The disign method and features of coyote blasting in quarrying rockfill material for the Doulingzi hydro power project are described. It is proved that effective control of the big size rocks can be achieved (Less than 8%) and the material gradation meets the requirements of the hydro power project.

Abstract:Description is made on the bid invitation and tendering manners and procedures, the contents and form of the tender documentation, the preparation principle and method of the tender documentation, the strategy of the tender price offer,as well as some items to be noted for geotechnical engineering projects.