Abstract:It has been successfulto mploy the planetary differential gear device to function as the automati sychronizer of GCF-1500 percussive reverse-circulation drills. The kinematical and force- balance principles of the device are analyzed. It is featured with simple structure and operation reliability.

Abstract:The basical theory of Geometrical planning and its implementation method in engineering machinery is described. Compared with conventional design meth-ods, Geometrical planning,used in spring optimization design of XRC- 1 manriding cars for inclined shafts,increases economy obviously.

Abstract:Described are features and functions of Ingersoll-rand cluste down the hole hammers and programs of construction three diaphragm walls ofdifferent structures using them, with emphasis on he sheet pile diaphragm wall construction procedure.

Abstract:A discussion is made on power adaption,axial load distribution of the replaced truck carriage and the transfer device position of the modified part in modification desing of DPP100-3 drills, which is primarily illustrated with the example of the selected CA141S truck carriage modification desing.

Abstract:By using of inclination measurements and on basis of the full angle curvature theory, the drill well bent curvature, curlature radius and stress of large diameteer well casing are calculated to guide safely placing large diameter well casing in deep wells and avoiding well casing bucling failure.

Abstract:Problems encountered in slim hole sealing are analyzed.Technical measures of medium -deep hole sealing are theoretically presented, through field application and penetration inspection of scores of drill holes, have proved to be feasible.

Abstract:Described are prooess of Vibro-tube sinking bored piles constructed in comples formations,and mea-sures of incaing single pile bearing capacity and bole completion & pile completion efficisncy, Problem ofVibro tube sinking bored piles is evaluated.

Abstract:A mathematical model used in under-water concrete injection of bored piles is proposed, according to which,the initial injection amount is calculated, the supplement injection is divided into five stages, and appoxi-mate calculation is made on the parameters relevant to the five stages,the calculation values are compared with those obtained from field construction cases and found to coincide with each other in general .

Abstract:Description is forcused on the drilling method and completion process of large diameter drainage holes in Huaibei coal mine. Full-sized drilling tools are used for deivation prevention,the best placedment of the upper,middli and lower stabilizers is determined, et drilling is chosen to increase drilling rate,and the check valve type floating plug located at the tube end is employed to tackle tube lowering and grouting problems.

Abstract:介绍了利用锚杆静压桩加固基础与沉井掏土纠偏方法纠治某厂房的施工过程，先用锚杆静压桩加固厂房基础，然后再用沉井掏土法纠治厂房，使偏斜率由３２‰纠到了３‰的安全界限。

Abstract:Laboratory tests are carried out on use of the consolidation method to treat waste mud with cement as consolidation agent,and other threatment additives;the proper formula is selected;and preliminary field tests are perfomed.

Abstract:Organization of large-scale chamber blasting is described in the case of Luoguogou, It is emphatically stated that the following points should be noted during technical desing:(1)spacing of charge roons and deter- mination of blasting parameters;(2)design of initiation network;(3) construction plan;(4) safety check and safety precautions.

Abstract:It provides simple operation safety & reliability and no danger to the adjecent buildings in the wake of blastin technique, The operation method of high- steered building blasting demolition by staged tilting over is describled with reference to field cased.

Abstract:Description on the coretruction process of combination support by anchor & wood frame in a gold mine shaft excavation, and its effect is also analyzed at last.

Abstract:The program of composing the construction network planning and the method of estimating the time spent on each construction step are described. The methods of time co- ordinate network profile drawing, network optimization and network management are discribed by exampes.

Abstract:This paper deseribes features,advantages, disadvantages,present development and application status of a few core drilling systems, suitable for scientific slim hole deep drilling, including wireline coring with hydro- hammers, retractable bit systems, retractable bit system-percussive rotary coring, retractable bit system- down hole motors, and intelligent wire-line coring, with future trend presented.