Using the spatial structure of the external staggered split-level panel layout,a combined support technology for adjacent roadways was developed and analyzed for a rock bolt and anchor cable mechanism.The influence of...Using the spatial structure of the external staggered split-level panel layout,a combined support technology for adjacent roadways was developed and analyzed for a rock bolt and anchor cable mechanism.The influence of the side rock bolt and anchor cable parameters on the mechanical properties of the anchorage body and the support stress distribution of the lateral coal body were revealed using the FLAC3D software.The optimal support parameters of the side rock bolts and anchor cables were subsequently determined,and the support effect of gob-side entry in a mining scenario was verified.The results show that the support of the side rock bolts and anchor cables improves the mechanical properties and stress state of the anchorage body,producing a good protective effect on the coal body of the air-intake entry roof and side wall.This is beneficial to the stability of the side wall and the realization of the suspension effect for roof rock bolts and anchor cables,which in turn makes the surrounding rock maintenance of the gob-side entry to a thick coal seam more favorable.展开更多
基于三维高斯泼溅(3DGS)的文本到三维模型生成方法虽在渲染效率与外观保真上取得进展,但因现有克隆分裂策略(如Pixel-GS、AbsGS、EDC)仅依赖梯度进行密度控制、缺乏局部几何复杂度感知,仍有在高曲率区域细节表现不足、低曲率区域冗余加...基于三维高斯泼溅(3DGS)的文本到三维模型生成方法虽在渲染效率与外观保真上取得进展,但因现有克隆分裂策略(如Pixel-GS、AbsGS、EDC)仅依赖梯度进行密度控制、缺乏局部几何复杂度感知,仍有在高曲率区域细节表现不足、低曲率区域冗余加密问题。为此,提出曲率引导的克隆分裂策略(curvature-guided cloning and splitting,CGCS),构建层次感知的显著性评分机制,结合协方差分析、结构张量与最小二乘曲率拟合等结构估计方法,提取候选点的法向、主方向与曲率响应,引导扰动方向与分裂幅度。进一步地,设计基于结构响应的扰动引导策略以增强高频区域细节,并引入法向一致性与排斥正则项,提升结构一致性并抑制冗余增长。CGCS可无缝集成至LucidDreamer与MV-TCO等主流文生3D框架,实验结果表明,其在提升语义一致性的同时将平均点数减少32.6%,并在CLIPScore、MV-SSIM等多项指标上均优于现有梯度驱动的自适应密度控制方法,展现出更强的结构适应性与部署效率。展开更多
Ground subsidence caused by extraction of longwall panels has always been a great concern all over the world.Conventional longwall mining system(CLMS)gives rise to wavy subsidence causing great damage to surface struc...Ground subsidence caused by extraction of longwall panels has always been a great concern all over the world.Conventional longwall mining system(CLMS)gives rise to wavy subsidence causing great damage to surface structures.A coal mine in Shanxi,China,utilizes a split-level longwall layout(SLL)for a sub-horizontal No.8 coal seam to improve the cavability of mudstone interlayer and top coal.This layout,however,also produced unexpectedly favorable surface subsidence.Subsidence of No.6 and No.8 longwall panels was monitored while mining was conducted.Field instrumentation and numerical simulation were carried out.It is demonstrated that an asymmetric subsidence profile with stepped subsidence and cracks occurred on the tailgate side but relatively mild and smooth deformation on the other.Due to elimination of conventional parallelepiped gate pillar,No.6 and No.8 gobs were connected.Extraction of two SLL panels acted as one supercritical panel.The maximum possible subsidence was reached which lowers the likelihood of potential future secondary subsidence as underground gob fractures and voids have closed.Therefore,SLL is more favorable for postmining land reuse as gobs are more consolidated underground.展开更多
基金National Natural Science Foundation of Surface Project of China(Grant Nos.5177428952074291)+2 种基金The National Natural Science Foundation of the Youth Science Foundation of China(Grant No.51404270)The Fundamental Research Funds for the Central Universities(Grant No.2011QZ06)The Open Fund of State Key Laboratory of Coal Resources in Western China(Grant No.SKLCRKF1903).
摘要Using the spatial structure of the external staggered split-level panel layout,a combined support technology for adjacent roadways was developed and analyzed for a rock bolt and anchor cable mechanism.The influence of the side rock bolt and anchor cable parameters on the mechanical properties of the anchorage body and the support stress distribution of the lateral coal body were revealed using the FLAC3D software.The optimal support parameters of the side rock bolts and anchor cables were subsequently determined,and the support effect of gob-side entry in a mining scenario was verified.The results show that the support of the side rock bolts and anchor cables improves the mechanical properties and stress state of the anchorage body,producing a good protective effect on the coal body of the air-intake entry roof and side wall.This is beneficial to the stability of the side wall and the realization of the suspension effect for roof rock bolts and anchor cables,which in turn makes the surrounding rock maintenance of the gob-side entry to a thick coal seam more favorable.
摘要基于三维高斯泼溅(3DGS)的文本到三维模型生成方法虽在渲染效率与外观保真上取得进展,但因现有克隆分裂策略(如Pixel-GS、AbsGS、EDC)仅依赖梯度进行密度控制、缺乏局部几何复杂度感知,仍有在高曲率区域细节表现不足、低曲率区域冗余加密问题。为此,提出曲率引导的克隆分裂策略(curvature-guided cloning and splitting,CGCS),构建层次感知的显著性评分机制,结合协方差分析、结构张量与最小二乘曲率拟合等结构估计方法,提取候选点的法向、主方向与曲率响应,引导扰动方向与分裂幅度。进一步地,设计基于结构响应的扰动引导策略以增强高频区域细节,并引入法向一致性与排斥正则项,提升结构一致性并抑制冗余增长。CGCS可无缝集成至LucidDreamer与MV-TCO等主流文生3D框架,实验结果表明,其在提升语义一致性的同时将平均点数减少32.6%,并在CLIPScore、MV-SSIM等多项指标上均优于现有梯度驱动的自适应密度控制方法,展现出更强的结构适应性与部署效率。
基金This study was funded by the General Program of the National Natural Science Foundation of China(52274092)Hu-Bao-E National Independent Innovation Demonstration Zone Construction Science and Technology Support Project(2023XM08)Funds for Talents Supported by the China Association for Science and Technol-0gy(YESS20200211).
摘要Ground subsidence caused by extraction of longwall panels has always been a great concern all over the world.Conventional longwall mining system(CLMS)gives rise to wavy subsidence causing great damage to surface structures.A coal mine in Shanxi,China,utilizes a split-level longwall layout(SLL)for a sub-horizontal No.8 coal seam to improve the cavability of mudstone interlayer and top coal.This layout,however,also produced unexpectedly favorable surface subsidence.Subsidence of No.6 and No.8 longwall panels was monitored while mining was conducted.Field instrumentation and numerical simulation were carried out.It is demonstrated that an asymmetric subsidence profile with stepped subsidence and cracks occurred on the tailgate side but relatively mild and smooth deformation on the other.Due to elimination of conventional parallelepiped gate pillar,No.6 and No.8 gobs were connected.Extraction of two SLL panels acted as one supercritical panel.The maximum possible subsidence was reached which lowers the likelihood of potential future secondary subsidence as underground gob fractures and voids have closed.Therefore,SLL is more favorable for postmining land reuse as gobs are more consolidated underground.