Abstract:This article introduces the general situation of Wenchuan earthquake scientific drilling project and the progress of drilling and logging engineering of the project. The characteristics of earthquake scientific drilling are analyzed and the organizational management for the implementation of the holes WFSD-1, WFSD-2 and WFSD-3-P is summarized. On the basis of organization and management experiences of Chinese Continental Scientific Drilling Project, the improvement measures on the organizational management for the Wenchuan project were discussed and put forward on the consideration of the exploration, complicated formations and engineering plan with frequent changes to meet the requirement of geoscientific research.

Abstract:This paper introduces the drilling operation of the WFSD-1 of the Wenchuan earthquake fault scientific drilling (WFSD) project as well as the experience gained and lessons learned during the hole drilling. Some extreme technical difficulties in the drilling operation, such as hole gushing water, broken formation, borehole collapse and tight hole, were overcome. A mud system with low water loss, high density and good lubrication properties was put to use to resolve mud expansion in fault gouge and diameter shrinkage resulted by geostatic stress. A twohaves tube coring technique was used to remain core in undisturbed state even in broken formation.

Abstract:Multi-type and multi-size split barrel coring technology were used in the hole WFSD-1 of Wenchuan earthquake fault scientific drilling project to ensure high core recovery rate and keep the cores in original state even in very complicated formation conditions. As a result, 94.3% of core recovery was achieved and the cores were in good original state, which meet the requirement of geo-scientific research.

Abstract:The first drilling hole of the Wenchuan earthquake fault science drilling project (WFSD-1) experienced up to more than 30 meters of the fault gouge drilling process. According to the research and application, the drilling mud system with high density, low water loss, low permeability, lubrication and resistance reducing was formed, and together with the equilibration by ground stress, coring in fault gouge was successfully made, which was the basis of the successful completion of the first hole construction in the Wenchuan earthquake fault scientific drilling.

Abstract:This article discussed the small annulus cementing technology, which was used for the hole of WFSD-1 of Wenchuan earthquake fault scientific drilling project in broken formation and fault gouge tight hole and introduced how to determine cementing parameters by combining the mud circulation pressure drop during test casing with the maximum bearing pressure of mud pump.

Abstract:In the complicated formation, 2 drill strings were broken in the hole WFSD-1 and 2 fishers were lost in it. Directional drilling was conducted to pass by the accident drilling tools. LZ-89 continuous whipstock was used for sidetracking at the bottom of the cement hole with the depth of 580.07m. A new hole was generated after 3m directional drilling in more than 3 hours. The paper introduced technical points of the directional drilling (sidetracking).

Abstract:Thick in-hole sediment affects drilling operation with drilling tool not going down to the hole bottom or drill bury. The paper introduced sediment treatment in the 3# hole of west Qingling with depth of 850m in engineering geological exploration of Lanzhou-Chongqing railway, and summed up some treatment experience and measures in treatment of sediment in broken formation for the similar drilling failure.

Abstract:Well X92 is a prospecting well set by Shengli Oilfield. In order to save investment, long open well drilling has been adopted in the 215.90mm hole, which is 3771m long. With complex geological conditions, there are not only general drilling difficulties, but also the coexisted various pressure strata with uncertain formation pressure coefficients, which is easy to cause drilling accident. These difficulties were overcome by reasonably controlling the performance of drilling fluid and adopting corresponding technologies of drilling fluid maintenance and treatment. The experience of this engineering case could be the reference for the long open well drilling design and construction in the same area.

Abstract:The mechanics model was established on the basis of simplifying structure and supporting of rotation axis in directive rotary steerable drilling system. Rotation equation, deflection curve equation, reaction and moment equation of the rotation axis under the static offset condition were derived and the location of offset force F was optimized, which provide a basis for theoretical calculation on engineering design and structure optimization for directive rotary steerable drilling system.

Abstract:This paper introduced a new type DTH hammer drilling with eccentric simultaneous casing about the structure composition and the design idea. In view of the complex situation of working environment and the force features, modeling was made on DTH hammer drilling tool, various load conditions were set and the working conditions of DTH hammer drilling were simulated with the finite element software ANSYS 11.0. According to the results of simulation analysis, improvement was made on the design of drilling tool and the results provide the theoretical basis for rationality and reliability of the new type DTH hammer.

Abstract:The mechanic and the thread conditions of drilling rod were discussed, and the innovation plan was put forward for drilling string thread, the advantages of innovated drilling rod thread was also presented.

Abstract:The paper introduced the application field of auger drilling technology with casing, and discussed several types of equipment and technological method, structural performance of casing and the construction technology.

Abstract:With an engineering case, the paper introduced a new support replacement plan when there is no condition for traditional support replacement construction. A row of bored cast-in-place piles are taken as retaining structure, 2 lines of steel concrete inner support in the excavation, 2 rows of deep cement mixing pile outside the piles as water-stop curtain which can prevent silt to get in. It is proved that this support replacement is safe and reliable.

Abstract:Sandy silt and mucky silt clay were often encountered in deep excavation in Shanghai, Jiangsu Province and Zhejiang Province, support replacement is designed to be done in this case. But by the analysis and checking on the monitoring data of excavation enclosure deformation and support axial-force in a station of 1# Line of Hangzhou subway, support replacement was stopped using. By the engineering practice, it was proved that with the combination of information construction and practical situations, construction efficiency was largely promoted without support replacement, which could be the reference for the similar deep excavation engineering.

Abstract:Because of the complicated geological conditions and the surrounding environment in the excavation site of Zhongnan Gardon Hotel, combined supporting method was adopted with shortcrete bolt and pile-anchor retaining. Safety for excavation construction, surrounding buildings and underground pipeline was ensured with lower cost and shorter construction period. The project set a successful case for similar engineering construction.

Abstract:Bored cast-in-place pile post grouting can promote the bearing capacity of single pile, guarantee the pile construction quality and save construction cost, which fit to bored cast-in-place pile engineering in bearing layers of sandy gravel and gravel soil. With the field case, the paper detailed the reinforcement mechanism, construction technology and treatment measures for construction difficulties.

Abstract:Effective calcium-treated mud was testing prepared for the underground salt-water environment with high sodium ion, and the serious pile hole shrinkage and un-position of steel reinforcement cage were solved. It can be the reference for the construction in the similar formation.

Abstract:Considering the geological engineering conditions and investment cost, the paper introduced the design, construction technology and the final effects of the application of composite foundation with plain concrete piles for high-rise building in Houma, which demonstrates the feasibility and practicability of the plain concrete pile for foundation treatment of high-rise building in this area.

Abstract:The loose soil, broken rocks, scarp and some overhanging structures were caused by the roadbed excavation. According to the requirements of this highway slope protection and local conditions, comprehensive protection measures with gravity retaining walls, shotcrete rockbolt mesh and lattice anchor rod were adopted. This paper introduces 3 technical features, various construction difficulties and the solutions in the construction process. Practice shows that the organic combination of 3 measures established a reliable security guarantee to slope protection in this area and new experience to highway slope protection was accumulated.

Abstract:Optimized design and tests were made on bit matrix formula, diamond parameters and bit nozzle to overcome slow drilling footage and short service life of the wire-line coring bit in hard and compact rock formation, the newly developed bit (S77), with good adaptability, overcame the drilling “sliding” in extra-hard to hard and mid to weak-abrasive rock formations.

Abstract:When the shield launching or arrival is under construction in the shield tunnel, it becomes the key to keep the soil stability in a period of the time before the rotary cutter head of shield machine penetrating into or drilling through the stratum. Based on the engineering case, this paper discussed the application of dual pipe highpressure spiral jet grouting piles in shield tunnel portal soil reinforcement about the principle of highpressure grouting, the grouting parameters and the construction technology. And some suggestions are put forward for spiral jet pile reinforcement and construction issues on shield launching or arrival.