1991年德国联邦物理技术研究院(PTB)开展了高分辨率高精度的新型角度比较仪的研制.其原因是,近年来角度测量技术已获得很大的进展,用于测量与生产技术的新型数字测角系统,受到了现有校准可能性的限制.大型望远镜新的测角系统,一再实现...1991年德国联邦物理技术研究院(PTB)开展了高分辨率高精度的新型角度比较仪的研制.其原因是,近年来角度测量技术已获得很大的进展,用于测量与生产技术的新型数字测角系统,受到了现有校准可能性的限制.大型望远镜新的测角系统,一再实现了更为精确的测量步骤.此外,惯性—角度测量技术,如激光陀螺仪和光纤陀螺仪,要求更高级的检测与校准设备.曾在1969年,Johannes Heidenhain公司向PTB提供了一种角度测量台,其分辨率为0.1 are sec.后来,将这一测角台装备了新的电子学系统,分辨能力达到0.01 aresec.1987年Heidenhain公司为PTB制造了一台分光仪,其测角台含0.01 are sec的测量步骤.该公司又于1991年与PTB合作,开发测量步骤为0.001 are sec的角度比较仪.展开更多
The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, dow...The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle.展开更多
文摘1991年德国联邦物理技术研究院(PTB)开展了高分辨率高精度的新型角度比较仪的研制.其原因是,近年来角度测量技术已获得很大的进展,用于测量与生产技术的新型数字测角系统,受到了现有校准可能性的限制.大型望远镜新的测角系统,一再实现了更为精确的测量步骤.此外,惯性—角度测量技术,如激光陀螺仪和光纤陀螺仪,要求更高级的检测与校准设备.曾在1969年,Johannes Heidenhain公司向PTB提供了一种角度测量台,其分辨率为0.1 are sec.后来,将这一测角台装备了新的电子学系统,分辨能力达到0.01 aresec.1987年Heidenhain公司为PTB制造了一台分光仪,其测角台含0.01 are sec的测量步骤.该公司又于1991年与PTB合作,开发测量步骤为0.001 are sec的角度比较仪.
基金Supported by National Natural Science Foundation of China (No. 51008116)State Key Laboratory of Coastal and Offshore Engineering (No. LP1014)+1 种基金Fundamental Research Funds for the Central Universities (No. 2009B14514)China Postdoctoral Science Foundation (No. 20090461062)
文摘The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle.