The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investi- gate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical a...The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investi- gate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carried out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lat- eral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.展开更多
Traditional construction techniques have a significant impact on the environment and are associated with long construction durations in the construction of municipal rainwater pipelines.Pipe jacking technology,a new t...Traditional construction techniques have a significant impact on the environment and are associated with long construction durations in the construction of municipal rainwater pipelines.Pipe jacking technology,a new type of pipeline construction method,enables non-excavation construction and can address the shortcomings of traditional pipeline construction.This article analyzes the concept and application advantages of pipe jacking technology.Combining engineering examples,it explores the application strategies of pipe jacking technology in the construction process of municipal rainwater pipelines for reference.展开更多
在驾驶舱的设计中应用人机工效学原理,利用JACK软件对舱内布局设计进行仿真及舒适性、可达域、可视域等工效进行评价,并提出修改意见。首先将基于人机工效学设计的驾驶舱的CATIA模型导入JACK软件中创建分析对象;然后基于JACK软件建立用...在驾驶舱的设计中应用人机工效学原理,利用JACK软件对舱内布局设计进行仿真及舒适性、可达域、可视域等工效进行评价,并提出修改意见。首先将基于人机工效学设计的驾驶舱的CATIA模型导入JACK软件中创建分析对象;然后基于JACK软件建立用于仿真工效分析的数字人模型(Digital Human Model),将数字人模型调整成驾驶员工作时的最优姿势,仿真驾驶员位于驾驶舱的虚拟环境。最后应用JACK软件的人机工效分析工具对驾驶舱内部进行分析并提出改进意见,这样既缩短了设计周期,又减少了设计制造费用。展开更多
基金Projects 2006BAB16B02 and 2006BAK03B06 supported by the National Scientific & Technological Foundation of China
文摘The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investi- gate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carried out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lat- eral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.
文摘Traditional construction techniques have a significant impact on the environment and are associated with long construction durations in the construction of municipal rainwater pipelines.Pipe jacking technology,a new type of pipeline construction method,enables non-excavation construction and can address the shortcomings of traditional pipeline construction.This article analyzes the concept and application advantages of pipe jacking technology.Combining engineering examples,it explores the application strategies of pipe jacking technology in the construction process of municipal rainwater pipelines for reference.
文摘在驾驶舱的设计中应用人机工效学原理,利用JACK软件对舱内布局设计进行仿真及舒适性、可达域、可视域等工效进行评价,并提出修改意见。首先将基于人机工效学设计的驾驶舱的CATIA模型导入JACK软件中创建分析对象;然后基于JACK软件建立用于仿真工效分析的数字人模型(Digital Human Model),将数字人模型调整成驾驶员工作时的最优姿势,仿真驾驶员位于驾驶舱的虚拟环境。最后应用JACK软件的人机工效分析工具对驾驶舱内部进行分析并提出改进意见,这样既缩短了设计周期,又减少了设计制造费用。
