The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this stu...The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this study,4 D seismic monitoring technology that is effective in reservoir development was used to monitor abnormal changes in coal-mine underground goaf to explore the feasibility of the method.Taking a coal mine in Hancheng,Shaanxi as an example,we used the aforementioned technology to dynamically monitor the abnormal changes in the goaf.Based on the 4 D seismic data obtained in the experiment and the abnormal change characteristics of the coal-mine goaf,the method of 4 D seismic data processing in reservoir was improved.A set of 4 D data processing flow for the goaf was established,and the anomalies in the surface elevation and overlying strata velocity caused by collapse were corrected.We have made the following improvements to the method of 4 D seismic data processing in the reservoir:(1)the static correction problem caused by the changes of surface elevation and destruction of the low-velocity layer has been solved through fusion static correction to comb the low-frequency components of elevation statics with the high-frequency components of refraction statics;(2)the problem of overlying strata velocity changes in the goaf caused by collapse has been solved through the velocity consistency method;(3)the problem of reflection event pull-down in the disturbance area has been solved through space-varying moveout correction based on cross-correlation;and(4)amplitude anomalies in the coal seam caused by the goaf have been addressed using the correction method of space-varying amplitude.Results show that the 4 D seismic data processing and interpretation method established in this study is reasonable and effective.展开更多
High-intensity earthquakes can cause severe damage to bridges,buildings,and ground surfaces,as well as disrupt human activities.Such earthquakes can create long-distance,high-intensity surface movements that negativel...High-intensity earthquakes can cause severe damage to bridges,buildings,and ground surfaces,as well as disrupt human activities.Such earthquakes can create long-distance,high-intensity surface movements that negatively impact bridge structures.This article delves into the seismic reduction and isolation design strategies for bridges in high-intensity earthquake areas.It analyzes various seismic reduction and isolation technologies and provides case studies to help relevant units understand the design strategies of these technologies.The results of this article can be used as a guideline to effectively enhance the seismic performance of bridges in high-intensity earthquake areas.展开更多
At present,earthquakes are a serious problem for building.Severe damages and collapses of buildings were caused by earthquakes in different degrees.It is reported that there are more than 68,858 deaths and hundreds of...At present,earthquakes are a serious problem for building.Severe damages and collapses of buildings were caused by earthquakes in different degrees.It is reported that there are more than 68,858 deaths and hundreds of billions RMB losses in the May 12,2008 Great Wenchuan Earthquake[16].So,more attention should be paid to seismic technology.In order to face the challenges of earthquake on building,the seismic retrofitting was put forward,which“is the modification of existing structures to make them more resistant to seismic activity,ground motion,or soil failure due to earthquakes”[2].展开更多
Compaction correction is a key part of paleogeomorphic recovery methods. Yet, the influence of lithology on the porosity evolution is not usually taken into account. Present methods merely classify the lithologies as ...Compaction correction is a key part of paleogeomorphic recovery methods. Yet, the influence of lithology on the porosity evolution is not usually taken into account. Present methods merely classify the lithologies as sandstone and mudstone to undertake separate porositydepth compaction modeling. However, using just two lithologies is an oversimplification that cannot represent the compaction history. In such schemes, the precision of the compaction recovery is inadequate. To improve the precision of compaction recovery, a depth compaction model has been proposed that involves both porosity and clay content. A clastic lithological compaction unit classification method, based on clay content, has been designed to identify lithological boundaries and establish sets of compaction units. Also, on the basis of the clastic compaction unit classification, two methods of compaction recovery that integrate well and seismic data are employed to extrapolate well-based compaction information outward along seismic lines and recover the paleo-topography of the clastic strata in the region. The examples presented here show that a better understanding of paleo-geomorphology can be gained by applying the proposed compaction recovery technology.展开更多
The Ordos basin is rich in oil and gas resources. The structures in the basin are generally rather gentle. Most of the oil and gas pools already found are belong to the types of lithologic, lithostratigraphic and pale...The Ordos basin is rich in oil and gas resources. The structures in the basin are generally rather gentle. Most of the oil and gas pools already found are belong to the types of lithologic, lithostratigraphic and paleo-geomorphic with thin reservoirs. The geology of oil and gas and the generation and distribution of oil and gas resources in the Ordos basin is analyzed in detail in the paper. It is also pointed out in the paper that what direction should be taken in oil and gas exploration in the basin, and that the important role of the seismic prospecting technologies in the discovery of large oil and gas fields in the basin could not be replaced.展开更多
This paper proposes an innovative low-cost isolator with lightweight and cost-effective features for use in low-rise residential buildings.The low-cost laminated isolator is formed by plastic shims with unsaturated po...This paper proposes an innovative low-cost isolator with lightweight and cost-effective features for use in low-rise residential buildings.The low-cost laminated isolator is formed by plastic shims with unsaturated polyester fiber reinforcement between rubber layers.Performance tests are systematically carried out to characterize the isolator in terms of mechanic behavior(e.g.,compression,shear,and their relationship),dynamic properties(e.g.,damping),and ultimate states.A design guideline and associated criteria of the low-cost isolator are also provided and discussed in this study.To investigate more detailed behavior,a finite element model of the isolator is developed in ABAQUS and calibrated by the experimental data.The research presented in this paper makes significant contributions to the evaluation of the peak stress and strain demands on isolator’s components and provides technical support for the design and manufacturing of this new type of isolator.展开更多
基金funded by the National Key Research and Development Program Subject(No.2018YFC0807804)。
文摘The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this study,4 D seismic monitoring technology that is effective in reservoir development was used to monitor abnormal changes in coal-mine underground goaf to explore the feasibility of the method.Taking a coal mine in Hancheng,Shaanxi as an example,we used the aforementioned technology to dynamically monitor the abnormal changes in the goaf.Based on the 4 D seismic data obtained in the experiment and the abnormal change characteristics of the coal-mine goaf,the method of 4 D seismic data processing in reservoir was improved.A set of 4 D data processing flow for the goaf was established,and the anomalies in the surface elevation and overlying strata velocity caused by collapse were corrected.We have made the following improvements to the method of 4 D seismic data processing in the reservoir:(1)the static correction problem caused by the changes of surface elevation and destruction of the low-velocity layer has been solved through fusion static correction to comb the low-frequency components of elevation statics with the high-frequency components of refraction statics;(2)the problem of overlying strata velocity changes in the goaf caused by collapse has been solved through the velocity consistency method;(3)the problem of reflection event pull-down in the disturbance area has been solved through space-varying moveout correction based on cross-correlation;and(4)amplitude anomalies in the coal seam caused by the goaf have been addressed using the correction method of space-varying amplitude.Results show that the 4 D seismic data processing and interpretation method established in this study is reasonable and effective.
文摘High-intensity earthquakes can cause severe damage to bridges,buildings,and ground surfaces,as well as disrupt human activities.Such earthquakes can create long-distance,high-intensity surface movements that negatively impact bridge structures.This article delves into the seismic reduction and isolation design strategies for bridges in high-intensity earthquake areas.It analyzes various seismic reduction and isolation technologies and provides case studies to help relevant units understand the design strategies of these technologies.The results of this article can be used as a guideline to effectively enhance the seismic performance of bridges in high-intensity earthquake areas.
文摘At present,earthquakes are a serious problem for building.Severe damages and collapses of buildings were caused by earthquakes in different degrees.It is reported that there are more than 68,858 deaths and hundreds of billions RMB losses in the May 12,2008 Great Wenchuan Earthquake[16].So,more attention should be paid to seismic technology.In order to face the challenges of earthquake on building,the seismic retrofitting was put forward,which“is the modification of existing structures to make them more resistant to seismic activity,ground motion,or soil failure due to earthquakes”[2].
文摘Compaction correction is a key part of paleogeomorphic recovery methods. Yet, the influence of lithology on the porosity evolution is not usually taken into account. Present methods merely classify the lithologies as sandstone and mudstone to undertake separate porositydepth compaction modeling. However, using just two lithologies is an oversimplification that cannot represent the compaction history. In such schemes, the precision of the compaction recovery is inadequate. To improve the precision of compaction recovery, a depth compaction model has been proposed that involves both porosity and clay content. A clastic lithological compaction unit classification method, based on clay content, has been designed to identify lithological boundaries and establish sets of compaction units. Also, on the basis of the clastic compaction unit classification, two methods of compaction recovery that integrate well and seismic data are employed to extrapolate well-based compaction information outward along seismic lines and recover the paleo-topography of the clastic strata in the region. The examples presented here show that a better understanding of paleo-geomorphology can be gained by applying the proposed compaction recovery technology.
文摘The Ordos basin is rich in oil and gas resources. The structures in the basin are generally rather gentle. Most of the oil and gas pools already found are belong to the types of lithologic, lithostratigraphic and paleo-geomorphic with thin reservoirs. The geology of oil and gas and the generation and distribution of oil and gas resources in the Ordos basin is analyzed in detail in the paper. It is also pointed out in the paper that what direction should be taken in oil and gas exploration in the basin, and that the important role of the seismic prospecting technologies in the discovery of large oil and gas fields in the basin could not be replaced.
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2012CB723304)Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT13057)+1 种基金the Ministry of Education Program for New Century Excellent Talents(Grant No.NCET-11-0914)the National Natural Science Foundation of China(Grant No.51278138)
文摘This paper proposes an innovative low-cost isolator with lightweight and cost-effective features for use in low-rise residential buildings.The low-cost laminated isolator is formed by plastic shims with unsaturated polyester fiber reinforcement between rubber layers.Performance tests are systematically carried out to characterize the isolator in terms of mechanic behavior(e.g.,compression,shear,and their relationship),dynamic properties(e.g.,damping),and ultimate states.A design guideline and associated criteria of the low-cost isolator are also provided and discussed in this study.To investigate more detailed behavior,a finite element model of the isolator is developed in ABAQUS and calibrated by the experimental data.The research presented in this paper makes significant contributions to the evaluation of the peak stress and strain demands on isolator’s components and provides technical support for the design and manufacturing of this new type of isolator.
