Anti-slide pile is one of the important methods to administer landslide geological disaster because of its advantages.It plays important role in administering landslide.It is a premise of reasonable economy and techno...Anti-slide pile is one of the important methods to administer landslide geological disaster because of its advantages.It plays important role in administering landslide.It is a premise of reasonable economy and technological advance to know the distribution rule and feature of the force between anti-sliding pile and surrounding rock.To determine the sliding force and remnant resistant sliding force,according to need of study,this paper sets up the geological model and mechanics model in term of a typical landslide,and analyzes the effect rule of sliding body distortion,strength and gravity to the pushing force and remnant resistant sliding force by use of the numerical model.The distribution rule of pushing force and remnant resistant sliding force of the type of landslide is given.展开更多
A rotary swaging machine was applied to fabricating pipe reduction for miniature inner grooved copper tube （MIGCT） heat pipes. Compared with conventional swaging method, the axial feed of the designed rotary swaging...A rotary swaging machine was applied to fabricating pipe reduction for miniature inner grooved copper tube （MIGCT） heat pipes. Compared with conventional swaging method, the axial feed of the designed rotary swaging machine was reached by a constant pushing force. The deformation of grooves in pipe reduced section during rotary swaging was analyzed. The shrinkage and extensibility of pipe reduction were measured and calculated. Furthermore, four aspects, including outer diameter, surface roughness, extensibility and processing time of pipe reduction, which were influenced by the pushing force, were considered. The results show that the tube wall thickness increases gradually along the z-axis at sinking section. However, the outer diameters, surface roughness and micro-cracks at reduced section tend to decrease along the z-axis. Besides, the effect of variation in the pushing force on the extensibility is limited while an increase in the pushing force results in a decrease of surface roughness. Therefore, a large pushing force within the limit is beneficial to pipe reduction manufacturing during rotary swaging process.展开更多
Now,the static push-the-bit rotary steerable system(SRSS)developed in China is being put into field tests and primary applications.During its normal drilling,higher frictional forces generated by the static pushing fo...Now,the static push-the-bit rotary steerable system(SRSS)developed in China is being put into field tests and primary applications.During its normal drilling,higher frictional forces generated by the static pushing forces of the rotary ribs on the wellbore wall influence the weight-on-bit(WOB)transmission efficiency and the rate of penetration(ROP).In this paper,analytical models of the WOB transmission efficiency were established for the wellbore wall with and without ladders respectively based on the structure and working principle of the SRSS.And the variation rules of the WOB transmission efficiency with the nominal WOB,the frictional coefficient of wellbore wall,the pushing force and the front chamfer of the steerable rib were analyzed.And the following research results were obtained.First,the nominal WOB of this SRSS has to satisfy the minimum requirement and it is conducive to the increase of WOB transmission efficiency by increasing the nominal WOB appropriately.Second,whether there are ladders on the wellbore wall or not,the WOB transmission efficiency decreases as the total pushing forces of steerable ribs and the frictional coefficient of wellbore wall increase.And the WOB transmission efficiency in the case of wellbore wall with ladders is much lower than that without ladders.Third,if there are ladders on the wellbore wall,the front chamfer of steerable rib has a significant effect on the WOB transmission efficiency.The larger the front chamfer is,the lower the WOB transmission efficiency is(even self-locking).In conclusion,the research results play an important role in guiding the rational selection and control of the WOB at drilling site.展开更多
文摘Anti-slide pile is one of the important methods to administer landslide geological disaster because of its advantages.It plays important role in administering landslide.It is a premise of reasonable economy and technological advance to know the distribution rule and feature of the force between anti-sliding pile and surrounding rock.To determine the sliding force and remnant resistant sliding force,according to need of study,this paper sets up the geological model and mechanics model in term of a typical landslide,and analyzes the effect rule of sliding body distortion,strength and gravity to the pushing force and remnant resistant sliding force by use of the numerical model.The distribution rule of pushing force and remnant resistant sliding force of the type of landslide is given.
基金Project (U0834002) supported by the Key Program of NSFC Guangdong Joint Funds of ChinaProjects (51005079, 20976055) supported by the National Natural Science Foundation of China+1 种基金Project (10451064101005146) supported by the Natural Science Foundation of Guangdong Province, ChinaProject (20100172120001) supported by Specialized Research Fund for the Doctoral Program of Higher Education, China
文摘A rotary swaging machine was applied to fabricating pipe reduction for miniature inner grooved copper tube （MIGCT） heat pipes. Compared with conventional swaging method, the axial feed of the designed rotary swaging machine was reached by a constant pushing force. The deformation of grooves in pipe reduced section during rotary swaging was analyzed. The shrinkage and extensibility of pipe reduction were measured and calculated. Furthermore, four aspects, including outer diameter, surface roughness, extensibility and processing time of pipe reduction, which were influenced by the pushing force, were considered. The results show that the tube wall thickness increases gradually along the z-axis at sinking section. However, the outer diameters, surface roughness and micro-cracks at reduced section tend to decrease along the z-axis. Besides, the effect of variation in the pushing force on the extensibility is limited while an increase in the pushing force results in a decrease of surface roughness. Therefore, a large pushing force within the limit is beneficial to pipe reduction manufacturing during rotary swaging process.
基金Project supported by the National Research Council of Science and Technology Major Project“Rotary Steering System Research and Development”(No.:2016ZX05022-002)the Surface Project of the National Natural Science Foundation of China“Study on Borehole Collission Prevention Mechanism Based on Magnetic Field Distribution and Passive Magnetic Ranging of Downhole Casing String”(No.:51674284)the Changjiang Scholars and Innovative Team Development Program of the Ministry of Education of the People's Republic of China.
文摘Now,the static push-the-bit rotary steerable system(SRSS)developed in China is being put into field tests and primary applications.During its normal drilling,higher frictional forces generated by the static pushing forces of the rotary ribs on the wellbore wall influence the weight-on-bit(WOB)transmission efficiency and the rate of penetration(ROP).In this paper,analytical models of the WOB transmission efficiency were established for the wellbore wall with and without ladders respectively based on the structure and working principle of the SRSS.And the variation rules of the WOB transmission efficiency with the nominal WOB,the frictional coefficient of wellbore wall,the pushing force and the front chamfer of the steerable rib were analyzed.And the following research results were obtained.First,the nominal WOB of this SRSS has to satisfy the minimum requirement and it is conducive to the increase of WOB transmission efficiency by increasing the nominal WOB appropriately.Second,whether there are ladders on the wellbore wall or not,the WOB transmission efficiency decreases as the total pushing forces of steerable ribs and the frictional coefficient of wellbore wall increase.And the WOB transmission efficiency in the case of wellbore wall with ladders is much lower than that without ladders.Third,if there are ladders on the wellbore wall,the front chamfer of steerable rib has a significant effect on the WOB transmission efficiency.The larger the front chamfer is,the lower the WOB transmission efficiency is(even self-locking).In conclusion,the research results play an important role in guiding the rational selection and control of the WOB at drilling site.
