边角后方交会在高铁板式无碴轨道放样中的应用     

陈慧建  周世健 《测绘与空间地理信息》2015,(4)

智能型全站仪结合边角后方交会原理在高速铁路测量工作中得到广泛应用,其在CPⅢ高精度铺轨控制网的基础上进行自由重叠设站的精度能满足高铁测量的精度要求。在板式无碴轨道底板放样和轨道板安装时,可以根据仪器误差参数计算得出每个测站进行放样时误差不超限的最远放样距离,供测量人员参考。  相似文献   

尼泊尔Ms8.1地震构造背景及对周边地区地震活动趋势的影响     

雷东宁  蔡永建  李恒  吴建超  乔岳强  余松  廉超 《大地测量与地球动力学》2015,35(5):738-741

分析印度板块与欧亚板块俯冲带、尼泊尔Ms8.1地震震中区地震构造及地震发震构造,讨论主震对余震触发及余震的时空强特征和地震对周边地区地震活动趋势的影响。初步分析认为,主边界断裂为本次地震的发震构造,属于低角度逆冲断层地震;余震分布范围与震源破裂面积和方式基本一致,具有向东迁移的时空特征;西藏定日Ms5.9、聂拉木Ms5.3地震不属于尼泊尔地震余震,是应力扰动的结果;沿俯冲带向东至喜马拉雅东构造结是大震发生的危险地段。  相似文献   

基于栅格叠置分析的分版审校模型的建立与应用     

汶建龙  史瑞芝 《测绘工程》2011,20(5):49-52

地图分版错误一直是困扰地图出版的重要因素之一,而目前的地图分版审校工作主要还是沿用传统的手工方式进行作业,因此,急需改进和完善,以满足当前数字化条件下地图快速生产的需求.文中提出并设计基于栅格叠置分析的分版审校模型,并通过实践进行验证.该模型与传统的手工分色版审校模式相比较,自动化、智能化程度进一步增强,大大提高审校的...  相似文献   

青藏高原东缘重力导纳模型均衡异常时空特征   总被引：13，自引：7，他引：6       下载免费PDF全文

陈石  王谦身  祝意青  蒋长胜  王武星  卢红艳  刘端法  郭凤义 《地球物理学报》2011,54(1):22-34

青藏高原东缘地处南北地震带,在卫星自由空气重力异常图上对应明显的正负异常梯级带变化特征,沿着异常梯级带分布多条深大断裂,属于构造单元的边界区域.本文利用重力导纳分析方法,计算了该区重力导纳模型均衡异常背景场;通过与Airy模型和弹性板模型的均衡重力异常特征对比,结合地震活动性分布特点,评价均衡重力异常计算结果和选择计算...  相似文献   

半刚接框架-斜加劲钢板剪力墙低周反复荷载试验研究     

郭宏超  郝际平  李峰 《地震工程与工程振动》2011,31(1):54-60

对一榀单跨两层半刚接框架-斜加劲钢板剪力墙结构进行了低周反复荷载试验,分析结构破坏模式和耗能机理,得到了承载力、延性、刚度、耗能能力等指标.结果表明:该种结构具有良好的延性和耗能性能,安全储备高;半刚框架和墙板协同工作良好;斜加劲肋的设置缓解了钢板沿拉力带方向的面外变形,提高了墙体的弹性屈曲倚载及初始刚度,减轻了滞回曲...  相似文献   

In situ stress field of eastern Australia     

R. R. Hillis  J. R. Enever  S. D. Reynolds 《Australian Journal of Earth Sciences》2013,60(5):813-825

New in situ data based on hydraulic fracturing and overcoring have been compiled for eastern Australia, increasing from 23 to 110 the number of in situ stress analyses available for the area between and including the Bowen and Sydney Basins. The Bowen Basin displays a consistent north‐northeast maximum horizontal stress (σ_H) orientation over some 500 km. Stress orientations in the Sydney Basin are more variable than in the Bowen Basin, with areas of the Sydney Basin exhibiting north‐northeast, northeast, east‐west and bimodal σ_H orientations. Most new data indicate that the overburden stress (σ_V) is the minimum principal stress in both the Bowen and Sydney Basins. The Sydney Basin is relatively seismically active, whereas the Bowen Basin is relatively aseismic. Despite the fact that in situ stress measurements sample the stress field at shallower depth than the seismogenic zone, there is a correlation between the stress measurements and seismicity in the two areas. Mohr‐Coulomb analysis of the propensity for failure in the Sydney Basin suggests 41% of the new in situ stress data are indicative of failure, as opposed to 13% in the Bowen Basin. The multiple pre‐existing structural grains in the Sydney Basin further emphasise the difference between propensity for failure in the two areas. Previous modelling of intraplate stresses due to plate boundary forces has been less successful at predicting stress orientations in eastern than in western and central Australia. Nonetheless, stress orientation in the Bowen Basin is consistent with that predicted by modelling of stresses due to plate boundary forces. Variable stress orientations in the Sydney Basin suggest that more local sources of stress, such as those associated with the continental margin and with local structure, significantly influence stress orientation. The effect of local sources of stress may be relatively pronounced because stresses due to plate boundary forces result in low horizontal stress anisotropy in the Sydney Basin.  相似文献   

Metamorphic evolution of the Naga Hills eclogite and blueschist, Northeast India: implications for early subduction of the Indian plate under the Burma microplate     

N. CHATTERJEE  N. C. GHOSE 《Journal of Metamorphic Geology》2010,28(2):209-225

Tectonic slices and lenses of eclogite within mafic and ultramafic rocks of the Early Cretaceous–Eocene Naga Hills ophiolite were studied to constrain the physical conditions of eastward subduction of the Indian plate under the Burma microplate and convergence rate prior to the India–Eurasia collision. Some of the lenses are composed of eclogite, garnet-blueschist, glaucophanite and greenschist from core to margin, representing a retrograde hydrothermal alteration sequence. Barroisite, garnet, omphacite and epidote with minor chlorite, phengite, rutile and quartz constitute the peak metamorphic assemblage. In eclogite and garnet-blueschist, garnet shows an increase in Mg and Fe and decrease in Mn from core to rim. In chlorite in eclogite, Mg increases from core to rim. Inclusions of epidote, glaucophane, omphacite and quartz in garnet represent the pre-peak assemblage. Glaucophane also occurs profusely at the rims of barroisite. The matrix glaucophane and epidote represent the post-peak assemblage. The Fe³⁺ content of garnet-hosted omphacite is higher than that of matrix omphacite, and Fe³⁺ increases from core to rim in matrix glaucophane. Albite occurs in late stage veins. P – T pseudosection analysis indicates that the Naga Hills eclogites followed a clockwise P – T path with prograde metamorphism beginning at ∼1.3 GPa/525 °C and peaking at 1.7–2.0 GPa/580–610 °C, and subsequent retrogression to ∼1.1 GPa/540 °C. A comparison of these P – T conditions with numerical thermal models of plate subduction indicates that the Naga Hills eclogites probably formed near the top of the subducting crust with convergence rates of ∼ 55–100 km Myr⁻¹, consistent with high pre-collision convergence rates between India and Eurasia.  相似文献   

江苏省区域旅游产业差异及“板块旅游”发展战略   总被引：5，自引：0，他引：5  

汪德根  刘昌雪 《地理与地理信息科学》2008,24(5)

建构区域旅游产业竞争力评价三级指标体系,运用层次分析法和聚类分析法测度江苏省区域旅游产业竞争力,并采用锡尔I(O)系数方法对旅游产业竞争力水平差异进行分解,从市场、效益、贡献、资源、设施、人才、经济、交通和环境9个细分指标揭示苏南、苏中和苏北地区旅游产业发展水平的差异。分析发现,苏南、苏中和苏北地区间差异明显,地区内部城际差异相对较小;苏南地区的整体旅游产业竞争力较强,而苏中和苏北地区相对较弱,苏南与苏中、苏北的旅游发展整体水平差距大,苏中与苏北的差距相对较小;江苏旅游产业竞争力的空间分异特点是"南强北弱"、"沿江强沿海弱"。提出重点打造四大旅游板块并构建跨区域旅游板块的"板块旅游"模式区域发展战略,旨在实现苏南、苏中和苏北旅游产业的相对均衡协调发展和旅游产业竞争力水平的整体提升。  相似文献   

法向承力锚拖曳安装过程的整体模拟     

王立忠  斯丽莎  国振  李玲玲  袁峰 《海洋工程》2012,30(3):18-28

法向承力锚(Vertically Loaded Plate Anchor,VLA)是一种适用于深水的新型系泊基础,它的拖曳安装过程直接决定了其系泊定位的精度和锚体的最终承载能力。综合考虑VLA锚体、锚泊线和上部船体的运动,建立了一种新的准静力整体分析模型。模型包括不断贯入海床的锚体、锚泊线(土中反悬链段和水中悬链段)和安装船体三部分,针对确定的锚泊线长度,安装船运动张紧锚泊线进行安装的过程,计算了此过程中锚体的运动轨迹、锚泊线形态和作用在船体上的锚泊线张力矢量的变化,重点分析了不同抛链长度和海床土体的参数对安装过程控制的影响,发现链长与水深之比达到5时,接近极限贯入深度。  相似文献   

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刘玉虎  刘兴旺  杨鑫  郑建京  王亚东  苏龙 《大地测量与地球动力学》2012,32(1):31-37

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