Abstract:Alternative process airdrilling has many advantages, which has been applied in water well and geothermal well for years and now has become hot application in coal mine gas discharge well, coal bed methane well, oil & gas well, solar energy well and all types of large diameter borehole engineering. Practice shows that pneumatic DTH hammer and airlift reverse circulation are most popular. The paper introduced the pneumatic DTH hammer and airlift reverse circulation drilling technology in their development situation, working principle, operation points and the application attentions.

Abstract:Electromagnetic measurement while drilling can provide large amount information with high transmission rate, this technique was rapidly applied and developed in recent years. The paper summarized the basic modes of electromagnetic signal transmission in downhole drilling, analyzed the structure parameters of downhole emitting electrode by equivalent transmission line with primary test. The results could only partly prove validity of the verification theory; other parts of parameter calculation could not get the reasonable explanation by theoretical model, which need further improvement to understand drilling rod / magnetotelluric transmission system.

Abstract:Selection of cutting carrying medium is very important for unbalanced drilling, which should protect oil & gas reservoir and keep the borehole stability. Oil-in-water system was firstly applied in the fourth unbalanced drilling section of Well Lishen 1. Optimized drilling fluid formula and scientific maintenance played well in oil & gas formation protection and borehole collapsing prevention, a new type of cutting carrying medium was developed for unbalanced drilling construction in this area.

Abstract:煤田钻探；护壁堵漏；绳索取心；泥浆

Abstract:With the drilling construction case in the complex formation of auriferous vanadium, the paper introduced the comprehensive construction with the application of lubrication drag reduction in shallow part and wall protection with high-quality mud in deep part, this construction technology has the characteristics of simple borehole structure, high efficiency, safe drilling, low cost and higher core recovery.

Abstract:Analysis was made on the advantages of low cost and high efficiency by open hole drilling with cemented carbide in Songyuan oil shale formation, specific measures were put forward for drilling in Songyuan oil shale formation and the rationality & effectiveness were verified by engineering case.

Abstract:According to the formation characteristics and construction requirement of Sijiaying iron mine, both wire-line coring and percussive-rotary wire-line drilling were adopted combined with diamond bit and washing fluid technology, drilling was successful.

Abstract:In this article, the effects of different drilling technical parameters on drilling efficiency are discussed and it had been suggested that the aim for optimized configuration of drilling equipment is to obtain the optimized drilling technical parameters and then the optimized drilling efficiency. The main elements of drilling equipment including drill rig, drilling method, WL coring drill rod, coring bit, directional drilling tools and mud pump are analyzed and the suggestions on the optimization of the elements are made. On the basis of elementary analysis, a proposal on the optimized configuration of deep exploration core drilling equipment is put forward.

Abstract:It is convenient and effective to design and analyze the transmission system of drilling rig by speed diagram, so the relationship of transmission pairs could be distinctly reflected. The existing problems of gearbox structure of GZ-ⅢA drilling rig were analyzed according to the speed diagram, modification was made on gearbox, the combination of gearbox and transfer case were adopted, which made the transmission route more reasonable.

Abstract:Based on the basic principle and the current situation of ground source heat pump system at home and abroad, analysis was made on some issues about promotion and publicity, design and construction, and later-stage management of closed-loop ground source heat pump system. And several suggestions were put forward to maintain the sustainable development of this system in the paper.

Abstract:The stress field of soils will change and bottom of foundation pit will upheave with excavation unloading. According to the relation between deformation and modulus of soil mass, the influence of pile foundation on modulus of soil mass and basal heave is studied. The process of excavation is simulated by the FEM software ANSYS, the trends of basal heave with or without pile foundation are calculated, and the influence of pile space, pile length and the loading on pile are discussed. The results of calculation are the same to the results of simulation test and basically the same to the field measurement.

Abstract:For the coal-storing pit surrounded by extremely complex environments, the design scheme is related to the normal production, safety and late maintenance works. In order to improve the supporting effect and avoid repeated maintenance, combined support with original supporting by the 8th Coal Mine of Pingdingshan, pile-anchor, soil-nailed meshing-concrete spraying and pre-stressed soil-nailing reinforcement was adopted with good effect. Based on the observation by information-construction method, the horizontal displacement of foundation pit and the settlement of the surrounding buildings are in a safe range, the safety of the foundation pit and the surrounding buildings were ensured.

Abstract:In the anti-seepage reinforcement for the quaternary ice conical cap and unconsolidated lacustrine accumulative formation, and according to the special plateau climate, engineering geological and hydro-geological conditions, high-pressure swing spraying grouting equipment & technology were improved and design parameters were optimized with ideal reinforcement effect achieved. It was verified by engineering example that in paramos freeze thawing region, seepage prevention by high-pressure swing spraying grouting was technically reliable and economic reasonable with obvious effect, which was worth popularizing in plateau area.

Abstract:Vertical shafts with short production life, small hole depth and diameter, which are constructed by drilling method with permanent steel lining sometimes, compared with reinforced concrete shaft lining, steel shaft lining easily causes buckling deformation even the shaft damage. With field cases, the paper analyzed the critical buckling stresses and influencing factors under the instability of steel shaft lining, and put forward the corresponding preventive measures.

Abstract:The paper discussed the reasons of bored hole collapsing in sandy aquifer construction with long-spiral driller and the technological principle of wall protection with grouting under-borehole with an engineering case; and also introduced the application and effect of this technology in long-spiral bored cast-in-situ pile, the application limit for long-spiral bored hole pile was broadened.

Abstract:Slope failure very likely occur if the deformed temporary slopes with cataclastic structure were not treated immediately, but cataclastic slope requested exigent support and the cost was also an important factor in the enginneering, these increased the treatment difficulties. The paper took the case of a cataclastic temporary slope on Dadu River, based on the characteristic of cataclastic temporary slope, treatment model was selected and the effects of working sequence of slope treatment were analyzed. Displacement monitoring in slope was made in first time and according to the feedback information, treatment scheme was adjusted with wire-netting shotcrete, prestressed anchorage cable, reinforcing steel bar piles and drainage engineering. Verification by numerical calculating and monitor data showed the treatment scheme was economy and applicable.

Abstract:Comprehensive treatment with anchor lattice, retaining wall and anti-slide pile was adopted for landslide control project in Three Gorges Reservoir. In order to increase the slide stability, it is important to construct the ultra-deep pre-stressed anchoring cable at top end of the anti-slide pile and increase the normal stress of slip band. The paper introduced the construction of ultra-deep pre-stressed anchoring cable, borehole for anchor cable, grouting and tension construction.

Abstract:The self-embedded landscape retaining wall has advantages of simple construction technology, good stability, low cost, aesthetics and environmental protection. In view of the technical problems in the construction of retaining walls,discussion on the key technical issues is made, and the corresponding technical measures are proposed in this paper.

Abstract:A new type of diamond-impregnated PDC bit was developed according to the characteristics of medium hard rock formation. The cutting structure， and principle were introduced. The PDC cutting tooth and the diamond-impregnated rear support can strengthen the role of cutting action to improve the drilling efficiency and the bit stability in medium hard rock with long service life.

Abstract:The paper emphatically introduced the technical measures, engineering effect and the construction experience in excavation, supporting and construction safety with the case of tunnel construction for under-construction Guangkun Railway in carbonaceous slate area.