Abstract:The article looked back briefly the development history of the core drilling techniques. The recent advances of drilling technology at the beginning of the 21st century are introduced. Examples of drilling techniques applied in the exploration of mineral resources are listed. The application cases of the drilling technique in the scientific drilling and environmental protection are briefly described.

Abstract:According to the difficulties of water well repairing and gravel-filling for horizontal well, porcelain granule pre-coated well screen was developed based on a lot of laboratory tests. PVC-U and porcelain granule were taken as the liner pipe and filter material with outstanding permeability of water and sand-resistance effect. The paper introduced the development process of the porcelain granule pre-coated well screen and the application.

Abstract:In recent years, horizontal directional drilling rig and oriented drilling technology play dominant role in pipeline construction with the rapid development of trenchless drilling machine. The paper emphatically introduced current horizontal directional drilling rig both in China and abroad about the transmission and driving mode of the power unit, feeding mode of feeding mechanism, clamping and loosing device, the chassis and the mechanism of drill stem mounting & dismounting device with the analysis on their advantages and disadvantages.

Abstract:Because of high-steep slope, difficulties are often encountered, such as drilling rig relocation & erection and borehole completion in crushed bottom. Anchor drill was selected and improved in order to meet the requirements for the anchor cable construction in accumulation body at high-steep slope; and meanwhile eccentric drill with casing was developed and manufactured, hoping to solve the difficulties of anchoring borehole construction in accumulation body at high-steep slope, overcome low efficiency and high cost.

Abstract:Wire-line drilling is widely used due to its high drilling efficiency; however, it cannot carry out directional drilling. The wire-line directional drilling and coring technology can take cores and drill directionally without using down-hole motors. The technology is a high-tech emerging in recent years, only a few countries have mastered it, and Norway and America lead the position in the world. This paper describes the wire-line directional drilling and coring principle and technical specifications with field application in Huaze mine of Yunnan.

Abstract:The construction of directional branch hole in steep orebody can not only save drilling workload, reduce drilling rig relocation and road repairing, but also is helpful for environmental protection and improving geological prospecting effect. This paper introduces the technology and processes of directional branch hole with LZ continuous whipstock in complex easily inclined stratigraphic.

Abstract:This article introduced the basic principles， the implementing points and the application effect of superimposing directional correction of inclination for deep exploration in Daye Iron Mine. A new idea was provided for solving the difficulties in the directional correction of inclination， and it was very important for borehole trajectory control.

Abstract:Niutouzhen geothermal field is with the best geothermal geological condition in North China, pipe equipment was transitioned from hydrological well series to API series. But the groundwater and the reservoir pressure lowered with the continuous exploitation of geothermal groundwater, and upper loose layer collapsing occurred while drilling in base rock weathering crust. According to this construction difficulty, improvement was made on drilling and well completion technology.

Abstract:In drilling of Daniudi gas field, hydrating swelling, spalling, block-falling and collapsing were the common phenomenon in the mudstone of Permian Shiqianfeng formation to lower Shihezi formation, which led to long drilling period. Potassium-ammonium polysulfonate drilling fluid system was found out based on the drilling experience of 2 horizontal wells, with which drilling efficiency was improved.

Abstract:In well gao15-19, the pressure was very similar in upper overflow layer with high pressure and lower leakage layer with low pressure, and the pressure window was small; construction was completed by applying a series of technical measures, and the experience was accumulated for such a long open hole.

Abstract:Because of high density of cementing slurry, borehole leakage often occurs while casing cementing operated in the area with low formation bearing pressure. Pressure sealing before well cementing is important to guarantee cementing quality and drilling design. Cementing of Well Lishen 1 was successfully operated by the analysis on the leakage zone and rational leakage stopping.

Abstract:Based on the status analysis on applicability of rotary drilling technique in home and abroad, through amount of engineering examples and spot practice, the author researched the applicability of rotary drilling technique and compared to normal & reverse circulation drilling. It includes construction efficiency, construction quality, applicability range, et al. In the last, the author suggested that optimum combination of the two costructuion methods should be applied in especial projects construction.

Abstract:The reinforced impervious soil-nailing wall is a new type of supporting system composed of soil nail and impervious wall, which has high water impermeability with high strength but low cost, and is suitable to foundation pit supporting engineering in silt and sand formation. Analysis was made on supporting mechanism and stress characteristics of the reinforced impervious soil-nailing wall in combination with a case of foundation pit engineering in Guangzhou, and conclusion was drawn that the characteristics of reinforced impervious soil-nailing wall, which was similar to ‘gravity retaining wall’ in range of bolt, came from the interaction of pressed grouting bolt, mixing piles and steel pipe pile. The monitoring data show that this foundation supporting system has sufficient safety reservation, and can be extended to foundation pit supporting project in similar formation.

Abstract:The paper introduced retaining structure scheme with row-pile + deep mixing pile and the design calculation process and summed up the retaining effect， which provides a successful example of excavation scheme for Yongcheng of Henan.

Abstract:According to the comprehensive analysis on the field situation and economic factors, necessary reinforcement measures were taken for a primary school playground to control the settlement by grouting reinforcement in backfilling layer in order to improve the mechanical properties of rock soil for the integrity restoration. In the field experiment and settlement monitoring for a year, the maximum settlement was only 15cm, and the settlement-time curve showed that the settlement is stable, which proved reinforcement effect satisfied the engineering requirement.

Abstract:According to the specific condition of a foundation pit project in Hangzhou, monitoring plan was designed with soil-nail wall support, light dewatering, bored-grouting pile, concrete internal-support and waterproof curtain, good reinforcement effect was obtained.

Abstract:It is necessary to deal with the space limit to provide enough reaction load for large tonnage vertical static loading test on narrow sites. According to the situation of large amount of bedrock in shallow bury in testing site， pre-stressed anchor cable was applied to the design of counterforce device， and reaction load was effectively solved by crossed counterforce device at last. The paper discussed the problems in the test， such as deformation of anchoring and anchor free sections with the improving suggestion.

Abstract:The paper discussed full-face drilling without drill pipe lifting and consolidating by stable grouting with the pressure increasing in hard quartzite layer with developmental joints. Close grouting time was prolonged in serious water gushing segment to meet the design requirement.

Abstract:Cofferdam method is often applied for bridge pier construction in the formations with big sand-pebble particles, peripheral anti-seepage method and the construction technology are very important for anti-seepage effect. Bi-slurry curtain grouting technology was selected for Nanzhou bridge of Guilin, the ideal application could be reference to similar projects.

Abstract:By the secondary pile testing in AWAR-AWAR 2×350MW pulverized power plant in Indonesia, the construction technology was modified with the improvement on bearing capacity of pile foundation in soft, loose, fractured, cavity and honeycomb structure developing and weathering limestone formation.

Abstract:It is difficult to carry out construction of bored cast-in-situ pile in the Karst area with high probability of quality problems. The article shows the analysis on the problems encountered during the course of bored piles construction in the Karst area, and it also provides the relevant technical countermeasures.

Abstract:The article introduces the construction technology and its advantages of the cast-in-place engaged pile taken as the exterior-protected structure used in the construction of Metro Line 1 Zhanong Kou-East Railway Station in the middle range of wind envelope well drilling project of Hangzhou， and sums up the measures to control the construction quality.