Based on 2D and 3D seismic data and well logging data,this paper studies the distribution of well-seismic stratigraphic filling and shoal controlled reservoirs of Upper Cambrian Xixiangchi Formation in the south slope...Based on 2D and 3D seismic data and well logging data,this paper studies the distribution of well-seismic stratigraphic filling and shoal controlled reservoirs of Upper Cambrian Xixiangchi Formation in the south slope of Leshan-Longnüsi paleouplift in the Sichuan Basin,to reveal the genetic relationship between stratigraphic filling,paleogeomorphology and large-scale grain shoal.(1)The Xixiangchi Formation in the study area is overlapped and filled gradually to the Leshan-Longnüsi paleouplift,but gets thin sharply due to truncation only near the denudation pinch-out line of the paleouplift.Two overlap slope break belts and one erosion slope break belt are identified,and the Xixiangchi Formation is divided into 4 members from bottom to top.(2)The filling pattern of the overlapping at the base and erosion at the top indicates that the thickness of Xixiangchi Formation can reflect the pre-depositional paleogeomorphology,and reveals that the studied area has a monoclinal geomorphic feature of plunging to southeast and being controlled by multistage slope break belts.(3)The large-scale grain shoals and shoal controlled reservoirs are developed longitudinally in the third and fourth members of the Xixiangchi Formation,and laterally in the vicinity of the multistage overlap slope break belts.(4)Overlap slope break belts are closely related to northwest trending reverse faults.The western margin of the South China Plate converging with the Qiangtang-Himalaya massif in the middle-late Cambrian resulted in the rapid uplift of the northwestern margin of the Yangtze Plate and expanding toward southeast,leaving gradually plunging multistage slope breaks and large-scale northeast grain shoal reservoir belts.Considering oil and gas test results,it is predicted that the favorable exploration zone of the grain shoal controlled reservoirs covers an area of 3340 km^(2).展开更多
The development, evolution and formation mechanism of faults and their control on the migration and accumulation of Mesozoic oil and gas in the middle-shallow layers of the slope zone of Mahu sag were studied by the i...The development, evolution and formation mechanism of faults and their control on the migration and accumulation of Mesozoic oil and gas in the middle-shallow layers of the slope zone of Mahu sag were studied by the interpretation of seismic and drilling data. Two types of faults, normal and strike-slip, are developed in the middle-shallow layers of the slope zone of the Mahu sag and they are mostly active in the Yanshanian period. They are divided into four grade faults: The grade I strike-slip faults with NWW to near EW direction are related to the left-lateral transpressive fault zones in the northwest of Junggar Basin since the end of the Triassic. The grade II faults with NE to NNE direction are the normal faults located at the junction of the fault zone and the slope zone, and their formation is related to the extension at the top of the nose-like structures in the fault zone. The grade III faults, which are also the normal faults, are the result of the extension at the top of the lower uplifts in the slope zone and differential compaction. The grade IV faults with NE direction are normal faults, which may be related to the extension environment at the tip of the lower uplifts. Faults not only are the channel for the vertical migration of oil and gas, but also control the oil-gas accumulation. There are two types of oil-gas reservoirs in the middle-shallow layers of slope zone of Mahu sag: fault block reservoirs and fault-lithologic reservoirs. They have large traps and promising exploration potential.展开更多
The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of signi...The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.展开更多
Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainl...Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainly focuses on blast center distance but neglects the amplification effect of blasting vibration waves by terraced terrain,from which the calculated blasting vibration velocities are smaller than the actual values,affecting the safety of the project.To address this issue,our model introduces the influences of slope and time into Sadowski formula to measure safety through blast vibration displacement.In the northern section of the open-pit quartz mine in Jinchang City,Gansu Province,China,the data of a continuous blasting slope project are referred to.Our findings reveal a noticeable vibration amplification effect during blasting when a multi-stage slope platform undergoes a sudden cross-sectional change near the upper overhanging surface.The amplification vibration coefficient increases with height,while vibration waves within rocks decrease from bottom to top.Conversely,platforms without distinct crosssectional changes exhibit no pronounced amplification during blasting.In addition,the vibration intensity decreases with distance as the rock height difference change propagates.The results obtained by the proposed blast vibration displacement equation incorporating slope shape influence closely agree with real-world scenarios.According to Pearson correlation coefficient(PPMCC)analysis,the average accuracy rate of our model is 88.84%,which exceeds the conventional Sadowski formula(46.92%).展开更多
The high and steep slopes along a high-speed railway in the mountainous area of Southwest China are mostly composed of loose accumulations of debris with large internal pores and poor stability,which can easily induce...The high and steep slopes along a high-speed railway in the mountainous area of Southwest China are mostly composed of loose accumulations of debris with large internal pores and poor stability,which can easily induce adverse geological disasters under rainfall conditions.To ensure the smooth construction of the high-speed railway and the subsequent safe operation,it is necessary to master the stability evolution process of the loose accumulation slope under rainfall.This article simulates rainfall using the finite element analysis software’s hydromechanical coupling module.The slope stability under various rainfall situations is calculated and analysed based on the strength reduction method.To validate the simulation results,a field monitoring system is established to study the deformation characteristics of the slope under rainfall.The results show that rainfall duration is the key factor affecting slope stability.Given a constant amount of rainfall,the stability of the slope decreases with increasing duration of rainfall.Moreover,when the amount and duration of rainfall are constant,continuous rainfall has a greater impact on slope stability than intermittent rainfall.The setting of the field retaining structures has a significant role in improving slope stability.The field monitoring data show that the slope is in the initial deformation stage and has good stability,which verifies the rationality of the numerical simulation method.The research results can provide some references for understanding the influence of rainfall on the stability of loose accumulation slopes along high-speed railways and establishing a monitoring system.展开更多
Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and ...Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.展开更多
Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and ...Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and tree-ring chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June-August and the com-bination of temperatures and moisture in the current May-July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBLO1 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBLO2 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May-July,while on the western slope,it was affected by the relative humidity in the previous June-August,the current May-July and the precipitation in the current May-July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.展开更多
The stability of open-pit mine slopes is crucial for safe and efficient mining operations.However,the presence of weak interlayers poses significant challenges in maintaining the stability of slopes.To explore the imp...The stability of open-pit mine slopes is crucial for safe and efficient mining operations.However,the presence of weak interlayers poses significant challenges in maintaining the stability of slopes.To explore the impact of the rock arching effect on slopes during excavation,understand the deformation zones and evaluation stages in such environments,and analyze the formation and characteristics of cracks,this study investigated the instability mechanism of open-pit mine slopes with weak interlayers through physical and numerical modeling.Focusing on the Zaharnur open-pit coal mine in China as a prototype,a sophisticated physical model test employing particle image velocimetry and Brillouin optical frequency domain analysis was conducted to comprehensively analyze the displacement and strain variation characteristics of open-pit mine slopes.The displacement,strain,stress redistribution,and failure processes of slopes under excavation were comprehensively analyzed through physical and numerical modeling.The results showed that the slope model exhibited a strain pattern in which the strain incrementally increased from its center toward the edges,and the landslide thrust was converted into an internal force along the arch axis and transmitted to the supports.The concept of the rock arching effect specific to soft rocks was proposed,shedding new light on an important phenomenon specific to open-pit slopes with weak interlayers.Based on its deformation characteristics,the slope could be divided into three areas:The excavation influence area,the crack area and the failure area.In addition,the ratios of the height and width of the outermost cracks to the excavation width fluctuated in the ranges of 0.36–0.49 and0.72–1.00,respectively.These findings contribute to a better understanding of the instability mechanisms in open-pit mine slopes with weak interlayers and provide valuable guidelines for safe mining practices.展开更多
基金Supported by the Cooperation Project of China National Natural Science Foundation and Petro China(U23B20154)Science and Technology Cooperation Project of Petro China and Southwest Petroleum University(2020CX010000)。
文摘Based on 2D and 3D seismic data and well logging data,this paper studies the distribution of well-seismic stratigraphic filling and shoal controlled reservoirs of Upper Cambrian Xixiangchi Formation in the south slope of Leshan-Longnüsi paleouplift in the Sichuan Basin,to reveal the genetic relationship between stratigraphic filling,paleogeomorphology and large-scale grain shoal.(1)The Xixiangchi Formation in the study area is overlapped and filled gradually to the Leshan-Longnüsi paleouplift,but gets thin sharply due to truncation only near the denudation pinch-out line of the paleouplift.Two overlap slope break belts and one erosion slope break belt are identified,and the Xixiangchi Formation is divided into 4 members from bottom to top.(2)The filling pattern of the overlapping at the base and erosion at the top indicates that the thickness of Xixiangchi Formation can reflect the pre-depositional paleogeomorphology,and reveals that the studied area has a monoclinal geomorphic feature of plunging to southeast and being controlled by multistage slope break belts.(3)The large-scale grain shoals and shoal controlled reservoirs are developed longitudinally in the third and fourth members of the Xixiangchi Formation,and laterally in the vicinity of the multistage overlap slope break belts.(4)Overlap slope break belts are closely related to northwest trending reverse faults.The western margin of the South China Plate converging with the Qiangtang-Himalaya massif in the middle-late Cambrian resulted in the rapid uplift of the northwestern margin of the Yangtze Plate and expanding toward southeast,leaving gradually plunging multistage slope breaks and large-scale northeast grain shoal reservoir belts.Considering oil and gas test results,it is predicted that the favorable exploration zone of the grain shoal controlled reservoirs covers an area of 3340 km^(2).
基金Supported by the China National Science and Technology Major Project(2017ZX05008-001,2011ZX05003-003)
文摘The development, evolution and formation mechanism of faults and their control on the migration and accumulation of Mesozoic oil and gas in the middle-shallow layers of the slope zone of Mahu sag were studied by the interpretation of seismic and drilling data. Two types of faults, normal and strike-slip, are developed in the middle-shallow layers of the slope zone of the Mahu sag and they are mostly active in the Yanshanian period. They are divided into four grade faults: The grade I strike-slip faults with NWW to near EW direction are related to the left-lateral transpressive fault zones in the northwest of Junggar Basin since the end of the Triassic. The grade II faults with NE to NNE direction are the normal faults located at the junction of the fault zone and the slope zone, and their formation is related to the extension at the top of the nose-like structures in the fault zone. The grade III faults, which are also the normal faults, are the result of the extension at the top of the lower uplifts in the slope zone and differential compaction. The grade IV faults with NE direction are normal faults, which may be related to the extension environment at the tip of the lower uplifts. Faults not only are the channel for the vertical migration of oil and gas, but also control the oil-gas accumulation. There are two types of oil-gas reservoirs in the middle-shallow layers of slope zone of Mahu sag: fault block reservoirs and fault-lithologic reservoirs. They have large traps and promising exploration potential.
基金supported by the National Natural Science Foundation of China (No.52374124)National Youth Science Foundation of China (No.52204135)+3 种基金Xing Liao Talent Plan (No.XLYC2202004)Young Elite Scientists Sponsorship Program by CAST (No.2023QNRC001)Liaoning Province International Science and Technology Cooperation Plan (No.2022JH2/1070004)Liaoning Natural Science Foundation Program (No.2022-BS-327)。
文摘The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.
文摘Blasting operations,which are crucial to open-pit mine production due to their simplicity and efficiency,require precise control through accurate vibration velocity calculations.The conventional Sadowski formula mainly focuses on blast center distance but neglects the amplification effect of blasting vibration waves by terraced terrain,from which the calculated blasting vibration velocities are smaller than the actual values,affecting the safety of the project.To address this issue,our model introduces the influences of slope and time into Sadowski formula to measure safety through blast vibration displacement.In the northern section of the open-pit quartz mine in Jinchang City,Gansu Province,China,the data of a continuous blasting slope project are referred to.Our findings reveal a noticeable vibration amplification effect during blasting when a multi-stage slope platform undergoes a sudden cross-sectional change near the upper overhanging surface.The amplification vibration coefficient increases with height,while vibration waves within rocks decrease from bottom to top.Conversely,platforms without distinct crosssectional changes exhibit no pronounced amplification during blasting.In addition,the vibration intensity decreases with distance as the rock height difference change propagates.The results obtained by the proposed blast vibration displacement equation incorporating slope shape influence closely agree with real-world scenarios.According to Pearson correlation coefficient(PPMCC)analysis,the average accuracy rate of our model is 88.84%,which exceeds the conventional Sadowski formula(46.92%).
基金supported by the National Natural Science Foundation of China (No.51978588).
文摘The high and steep slopes along a high-speed railway in the mountainous area of Southwest China are mostly composed of loose accumulations of debris with large internal pores and poor stability,which can easily induce adverse geological disasters under rainfall conditions.To ensure the smooth construction of the high-speed railway and the subsequent safe operation,it is necessary to master the stability evolution process of the loose accumulation slope under rainfall.This article simulates rainfall using the finite element analysis software’s hydromechanical coupling module.The slope stability under various rainfall situations is calculated and analysed based on the strength reduction method.To validate the simulation results,a field monitoring system is established to study the deformation characteristics of the slope under rainfall.The results show that rainfall duration is the key factor affecting slope stability.Given a constant amount of rainfall,the stability of the slope decreases with increasing duration of rainfall.Moreover,when the amount and duration of rainfall are constant,continuous rainfall has a greater impact on slope stability than intermittent rainfall.The setting of the field retaining structures has a significant role in improving slope stability.The field monitoring data show that the slope is in the initial deformation stage and has good stability,which verifies the rationality of the numerical simulation method.The research results can provide some references for understanding the influence of rainfall on the stability of loose accumulation slopes along high-speed railways and establishing a monitoring system.
基金the National Natural Science Foundation of China(No.4207741741671042)。
文摘Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.
基金supported by the National Natural Science Foundation of China (No.42077417,41671042).
文摘Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and tree-ring chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June-August and the com-bination of temperatures and moisture in the current May-July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBLO1 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBLO2 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May-July,while on the western slope,it was affected by the relative humidity in the previous June-August,the current May-July and the precipitation in the current May-July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.
基金supported by the National Natural Science Foundation of China(Nos.52204135 and 52374124)Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2023QNRC001)+2 种基金Basic Research Project of Liaoning Provincial Department of Education,China(No.LJ222410147010)2022 China Liaoning International Science and Technology Cooperation Plan Project(No.2022JH2/10700004)Ordos Major Science and Technology Program,(No.JBGS-2023-003)。
文摘The stability of open-pit mine slopes is crucial for safe and efficient mining operations.However,the presence of weak interlayers poses significant challenges in maintaining the stability of slopes.To explore the impact of the rock arching effect on slopes during excavation,understand the deformation zones and evaluation stages in such environments,and analyze the formation and characteristics of cracks,this study investigated the instability mechanism of open-pit mine slopes with weak interlayers through physical and numerical modeling.Focusing on the Zaharnur open-pit coal mine in China as a prototype,a sophisticated physical model test employing particle image velocimetry and Brillouin optical frequency domain analysis was conducted to comprehensively analyze the displacement and strain variation characteristics of open-pit mine slopes.The displacement,strain,stress redistribution,and failure processes of slopes under excavation were comprehensively analyzed through physical and numerical modeling.The results showed that the slope model exhibited a strain pattern in which the strain incrementally increased from its center toward the edges,and the landslide thrust was converted into an internal force along the arch axis and transmitted to the supports.The concept of the rock arching effect specific to soft rocks was proposed,shedding new light on an important phenomenon specific to open-pit slopes with weak interlayers.Based on its deformation characteristics,the slope could be divided into three areas:The excavation influence area,the crack area and the failure area.In addition,the ratios of the height and width of the outermost cracks to the excavation width fluctuated in the ranges of 0.36–0.49 and0.72–1.00,respectively.These findings contribute to a better understanding of the instability mechanisms in open-pit mine slopes with weak interlayers and provide valuable guidelines for safe mining practices.
