During the construction and operation of the abandoned mine pumped storage power station,the underground space surrounding rock body faces the complex stress environment under the action of mining disturbance,frequent...During the construction and operation of the abandoned mine pumped storage power station,the underground space surrounding rock body faces the complex stress environment under the action of mining disturbance,frequent pumping,water storage and other dynamic disturbances.The stability of the abandoned mine surrounding rock body is the basis for guaranteeing the safety and effectiveness of water storage in the underground space of the abandoned mine.By considering the two main factors of different stress levels and disturbance amplitudes,the mechanical properties,damage characteristics and acoustic emission characteristics of the abandoned mine perimeter rock body under dynamic disturbance were investigated using a creep-disturbed dynamic impact loading system.The experimental results show that:1)The stress level is considered to be the major contributing factor of the failure of muddy sandstone,followed by the amplitude of the disturbances;2)The time required for the destruction of muddy sandstone decreases with the increase of amplitude.When the stress level is 80%,the sandstone specimens have a decreasing number of cycles as the disturbance amplitude increases.The disturbance amplitude is sequentially increased from 4 MPa to 5,6,7,and 8 MPa,the number of cycles required for specimen destruction decreases significantly by 96.71%,99.13%,99.60%,and 99.93%,respectively;3)Disturbance amplitude and stress level have a significant effect on muddy sandstone damage and damage occurs only after a certain threshold is reached.With the increase of stress level and disturbance amplitude,the macroscopic damage of muddy sandstone is mainly conical,with obvious flake spalling and poor damage integrity;4)According to the time-dependent changes in AE energy and ringing counts,the acoustic emission activity during the failure process could be divided into three phases,namely,weakening period,smooth period,and surge period,corresponding to the compaction phase,elastic rise phase and post-peak damage phase.The research results are of reference significance for the damage evolution analysis of muddy sandstone under dynamic disturbance and the safety and stability of abandoned mine perimeter rock body.展开更多
It has been found that the existence of chlorite and illite will lead to the rock wettability of oil affinity.Chlorite and illite are developed in shaly sandstone of Yingcheng Formation in Longfengshan area,the satura...It has been found that the existence of chlorite and illite will lead to the rock wettability of oil affinity.Chlorite and illite are developed in shaly sandstone of Yingcheng Formation in Longfengshan area,the saturation index n of 7 rock samples is very high,with the highest of 14.57,whereas the cementation index m is low.The X-ray diffraction of clay and whole rock analysis of 7 shaly sandstone samples are carried out,and the relationship between chlorite and illite content vs.m and n is established.It is concluded that the low m value and high n value are caused by the wettability of rock.In order to verify the influence of wettability on the parameters of rock electricity,this paper discusses the method of making artificial shaly sandstone and the control of wettability.This study provides certain reference for determining the saturation model of shaly sandstone and improving the logging interpretation accuracy of shaly sandstone reservoirs.展开更多
基金Project(52204101)supported by the National Natural Science Foundation of ChinaProject(ZR2022QE137)supported by the Natural Science Foundation of Shandong Province,ChinaProject(SKLGDUEK2023)supported by the Open Project of State Key Laboratory for Geomechanics and Deep Underground Engineering in China University of Mining&Technology,Beijing,China。
文摘During the construction and operation of the abandoned mine pumped storage power station,the underground space surrounding rock body faces the complex stress environment under the action of mining disturbance,frequent pumping,water storage and other dynamic disturbances.The stability of the abandoned mine surrounding rock body is the basis for guaranteeing the safety and effectiveness of water storage in the underground space of the abandoned mine.By considering the two main factors of different stress levels and disturbance amplitudes,the mechanical properties,damage characteristics and acoustic emission characteristics of the abandoned mine perimeter rock body under dynamic disturbance were investigated using a creep-disturbed dynamic impact loading system.The experimental results show that:1)The stress level is considered to be the major contributing factor of the failure of muddy sandstone,followed by the amplitude of the disturbances;2)The time required for the destruction of muddy sandstone decreases with the increase of amplitude.When the stress level is 80%,the sandstone specimens have a decreasing number of cycles as the disturbance amplitude increases.The disturbance amplitude is sequentially increased from 4 MPa to 5,6,7,and 8 MPa,the number of cycles required for specimen destruction decreases significantly by 96.71%,99.13%,99.60%,and 99.93%,respectively;3)Disturbance amplitude and stress level have a significant effect on muddy sandstone damage and damage occurs only after a certain threshold is reached.With the increase of stress level and disturbance amplitude,the macroscopic damage of muddy sandstone is mainly conical,with obvious flake spalling and poor damage integrity;4)According to the time-dependent changes in AE energy and ringing counts,the acoustic emission activity during the failure process could be divided into three phases,namely,weakening period,smooth period,and surge period,corresponding to the compaction phase,elastic rise phase and post-peak damage phase.The research results are of reference significance for the damage evolution analysis of muddy sandstone under dynamic disturbance and the safety and stability of abandoned mine perimeter rock body.
基金projects of Science and Technology Development Excellent Young Talents of Jilin Province(No.20190103150JH)Science and Technology Development Plan of Jilin Province(No.20170201001SF).
文摘It has been found that the existence of chlorite and illite will lead to the rock wettability of oil affinity.Chlorite and illite are developed in shaly sandstone of Yingcheng Formation in Longfengshan area,the saturation index n of 7 rock samples is very high,with the highest of 14.57,whereas the cementation index m is low.The X-ray diffraction of clay and whole rock analysis of 7 shaly sandstone samples are carried out,and the relationship between chlorite and illite content vs.m and n is established.It is concluded that the low m value and high n value are caused by the wettability of rock.In order to verify the influence of wettability on the parameters of rock electricity,this paper discusses the method of making artificial shaly sandstone and the control of wettability.This study provides certain reference for determining the saturation model of shaly sandstone and improving the logging interpretation accuracy of shaly sandstone reservoirs.
