The Xinfengjiang reservoir in Guangdong Province is one of the large reservoirs that have triggered earthquakes of magnitude greater than 6.Numerous earthquakes have occurred since the impoundment of the reservoir,mak...The Xinfengjiang reservoir in Guangdong Province is one of the large reservoirs that have triggered earthquakes of magnitude greater than 6.Numerous earthquakes have occurred since the impoundment of the reservoir,making it one of the most active seismic zones in south China.In 2015,a set of deep-hole resistivity anomalies was observed in the Heping geoelectric station in Dongyuan county,located near the Xinfengjiang reservoir.After a field investigation,we found that a planned well drilling construction of new measuring channels was being carried out during that corresponding period of time.After careful comparison and analysis on the basis of the collected raw data,we had a reason to believe that drilling construction,rather than the inducement of the Xinfengjiang reservoir,was the main culprit for those unusual georesistivity values.So as to verify the above conjecture,we constructed a series of 3D finite element models based on the geological and hydrological infor-mation around Heping station and analyzed the drilling disturbances,respectively.Some significant conclusions were finally drawn according to the precise numerical simulation.This study gives a good example by combining numerical simulation with engineering practice as a way to understand the root cause of georesistivity anomalies in reality.展开更多
In the study of the application effectiveness of deep-hole controlled pre-splittingblasting technology,it was found through laboratory micro test and field study on a mine insouth China that under the technology,coal ...In the study of the application effectiveness of deep-hole controlled pre-splittingblasting technology,it was found through laboratory micro test and field study on a mine insouth China that under the technology,coal masses produce many irreversible cracks.Afterblasting,the nearer the distance from blasting hole,the larger the BET surface areaand volume ratio of the infiltration pore are;they increased by 11.47%and 5.73%,respectively.The coefficient of air permeability is increased 4 times.After 3 months,the gasdrainage rate was increased by 66%.In the first 15 days,the cumulative pumped gas was1.93 times of blasting before.The average absolute gas emission decreased by 63.46%.Experimental results show that deep-hole controlled pre-splitting blasting not only preventscoal and gas outburst,but also gives good economic results.展开更多
Created a new damage model for explosive for LS-DYNA3D,taking advantageof the Taylor method aimed at the high gassy and low permeability coal seam,and numericallysimulated and analyzed the deep-hole presplitting explo...Created a new damage model for explosive for LS-DYNA3D,taking advantageof the Taylor method aimed at the high gassy and low permeability coal seam,and numericallysimulated and analyzed the deep-hole presplitting explosion.The entire processof explosion was represented,including cracks caused by dynamic pressure,transmissionand vibration superposition of stress waves,as well as cracks growth driven by gas generatedby explosion.The influence of the cracks generated in the process of explosion andthe performance of improving permeability caused by the difference of interval between.explosive holes were analyzed.A reasonable interval between explosive holes of deepholepresplitting explosions in high gassy and low permeability coal seams was proposed,and the resolution of gas drainage in high gassy and low permeability coal seam was putforward.展开更多
A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, ...A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional micro-adjusting mechanism to realize the precise positioning. By LabView software this system is controlled to run automatically, to carry out calibration and automatic data collection, and to make data import into the database directly. Experiments proved that the diameter measurement range of the system can be 1.8 mm—7 mm, the resolution can be up to 5 nm—10 nm, the repeatability measurement standard deviation can be 0.05 μm—0.1 μm, and the measurement uncertainty can achieve 0.15 μm—0.3 μm. So the measuring system can realize the nanometer-level measurement.展开更多
采用随机方法分析了蕴含轴向流动流体的BTA(boring and trepanning association)深孔镗杆在随机力下的横向随机动力行为。建模时考察了流固耦合镗杆承受的弯曲、拉伸和扭转变形;经Galerkin Method离散化处理,分析了BTA镗杆在有、无随机...采用随机方法分析了蕴含轴向流动流体的BTA(boring and trepanning association)深孔镗杆在随机力下的横向随机动力行为。建模时考察了流固耦合镗杆承受的弯曲、拉伸和扭转变形;经Galerkin Method离散化处理,分析了BTA镗杆在有、无随机激励两种情况的特征值和特征频率对振动特性的影响;利用响应方差最大值和谱密度解析了BTA镗杆横向振动的临界转速与临界失稳频率;明确了镗杆随转速、刚度、初始轴向总力和剪切模量等参数变化对系统振动特性的影响机制:镗杆转速变化对系统稳定性不再具有单调性,随BTA镗杆转速持续增加,系统可历经两次转速的临界失稳,相继出现二次失稳和二次稳定;增加系统等效刚度和等效剪切模量会促进工作过程的稳定,改变轴向力对工作过程稳定的影响不明显;并以随机振动物理试验信号的功率谱分析,验证了理论仿真结果与试验结果的一致性。该研究在一定程度上揭示了BTA深孔工艺系统运动状态的复杂性,这种研究模式为进一步分析在复杂状态下的运动演化提供了更多的可能。研究结论为更好地理解BTA深孔镗杆工作时的随机动力行为提供了依据,也为BTA深孔工艺过程的振动控制和参数优化奠定了理论基础。展开更多
基金Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.311021002).
文摘The Xinfengjiang reservoir in Guangdong Province is one of the large reservoirs that have triggered earthquakes of magnitude greater than 6.Numerous earthquakes have occurred since the impoundment of the reservoir,making it one of the most active seismic zones in south China.In 2015,a set of deep-hole resistivity anomalies was observed in the Heping geoelectric station in Dongyuan county,located near the Xinfengjiang reservoir.After a field investigation,we found that a planned well drilling construction of new measuring channels was being carried out during that corresponding period of time.After careful comparison and analysis on the basis of the collected raw data,we had a reason to believe that drilling construction,rather than the inducement of the Xinfengjiang reservoir,was the main culprit for those unusual georesistivity values.So as to verify the above conjecture,we constructed a series of 3D finite element models based on the geological and hydrological infor-mation around Heping station and analyzed the drilling disturbances,respectively.Some significant conclusions were finally drawn according to the precise numerical simulation.This study gives a good example by combining numerical simulation with engineering practice as a way to understand the root cause of georesistivity anomalies in reality.
基金Supported by Project from National Natural Science Foundation of China(50674111)the National key Technology R&D Program in 10th Five Years Plan of China
文摘In the study of the application effectiveness of deep-hole controlled pre-splittingblasting technology,it was found through laboratory micro test and field study on a mine insouth China that under the technology,coal masses produce many irreversible cracks.Afterblasting,the nearer the distance from blasting hole,the larger the BET surface areaand volume ratio of the infiltration pore are;they increased by 11.47%and 5.73%,respectively.The coefficient of air permeability is increased 4 times.After 3 months,the gasdrainage rate was increased by 66%.In the first 15 days,the cumulative pumped gas was1.93 times of blasting before.The average absolute gas emission decreased by 63.46%.Experimental results show that deep-hole controlled pre-splitting blasting not only preventscoal and gas outburst,but also gives good economic results.
基金Supported by the National Science Foundation of China(50534090,2007BAK28B01,2007BAK29B06)the Science Foundation of Anhui Province(050440403)Creative Team Plan for High School of Anhui(2006KJ005TD)
文摘Created a new damage model for explosive for LS-DYNA3D,taking advantageof the Taylor method aimed at the high gassy and low permeability coal seam,and numericallysimulated and analyzed the deep-hole presplitting explosion.The entire processof explosion was represented,including cracks caused by dynamic pressure,transmissionand vibration superposition of stress waves,as well as cracks growth driven by gas generatedby explosion.The influence of the cracks generated in the process of explosion andthe performance of improving permeability caused by the difference of interval between.explosive holes were analyzed.A reasonable interval between explosive holes of deepholepresplitting explosions in high gassy and low permeability coal seams was proposed,and the resolution of gas drainage in high gassy and low permeability coal seam was putforward.
文摘A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional micro-adjusting mechanism to realize the precise positioning. By LabView software this system is controlled to run automatically, to carry out calibration and automatic data collection, and to make data import into the database directly. Experiments proved that the diameter measurement range of the system can be 1.8 mm—7 mm, the resolution can be up to 5 nm—10 nm, the repeatability measurement standard deviation can be 0.05 μm—0.1 μm, and the measurement uncertainty can achieve 0.15 μm—0.3 μm. So the measuring system can realize the nanometer-level measurement.
文摘采用随机方法分析了蕴含轴向流动流体的BTA(boring and trepanning association)深孔镗杆在随机力下的横向随机动力行为。建模时考察了流固耦合镗杆承受的弯曲、拉伸和扭转变形;经Galerkin Method离散化处理,分析了BTA镗杆在有、无随机激励两种情况的特征值和特征频率对振动特性的影响;利用响应方差最大值和谱密度解析了BTA镗杆横向振动的临界转速与临界失稳频率;明确了镗杆随转速、刚度、初始轴向总力和剪切模量等参数变化对系统振动特性的影响机制:镗杆转速变化对系统稳定性不再具有单调性,随BTA镗杆转速持续增加,系统可历经两次转速的临界失稳,相继出现二次失稳和二次稳定;增加系统等效刚度和等效剪切模量会促进工作过程的稳定,改变轴向力对工作过程稳定的影响不明显;并以随机振动物理试验信号的功率谱分析,验证了理论仿真结果与试验结果的一致性。该研究在一定程度上揭示了BTA深孔工艺系统运动状态的复杂性,这种研究模式为进一步分析在复杂状态下的运动演化提供了更多的可能。研究结论为更好地理解BTA深孔镗杆工作时的随机动力行为提供了依据,也为BTA深孔工艺过程的振动控制和参数优化奠定了理论基础。
