Study on Key Technology of Using Shell Sand as Backfill for Sea Reclamation   总被引：1，自引：0，他引：1  

郦能惠瞿亦容  何文钦陈晖 《中国海洋工程》2005,19(4):647-658

1 .IntroductionEpicontinental sea or land could formfromcontinental shelf because of the decreasing sea levelduring Quaternary.There is a large-area shell sand deposit more than ten meters thick in the neriticzone of China .To use the abundant marine shell sandresource as engineering material for ocean engi-neering and port engineeringis veryimportant .Sand (Gred and Bjorn,1999) ,fine sand (Zhangetal .,2002) , mediumand coarse sand (Qiuet al .,1995) ,highly weathered stone ballast (Zhanetal…  相似文献   

西藏崩错8级地震地表破裂的变形特征及其破裂机制   总被引：7，自引：2，他引：5       下载免费PDF全文

吴章明  邓起东 《地震地质》1989,11(1):15-25

1951年11月18日,西藏那曲崩错附近发生了一次8级地震,地表产生了长达约91公里的破裂带。本文总结了该破裂的几何、位移分布特征,讨论了破裂的形成机制和崩错地震的发震构造条件  相似文献   

On the instability of “folded” equilibria of a flexible nonstretchable thread attached to the satellite in a circular orbit     

Stanislav D. Furta 《Celestial Mechanics and Dynamical Astronomy》1992,53(3):255-266

The author considers a problem of Lyapunov's stability of relative equilibria of a flexible nonstretchable thread attached to the satellite moving in a circular Keplerian orbit in the first approximation. When it is in the position of relative equilibrium, the thread is known to be situated either along the radius vector of the orbit (the radial equilibrium) or along the circular orbit (the tangential equilibrium) and in each case the thread can be in a folded state. The author shows that folded radial equilibria of the thread are always unstable while tangential ones are unstable if the thread is sufficiently short in comparison with the radius of the orbit. The generalized Chetaev functional has been constructed to prove the instability.  相似文献   

GPS技术在山区石油地震勘探测量中的应用     

刘兵  施昆  韦瑞表  缪祥柱 《测绘工程》2008,17(6):63-66

针对GPS技术在山区石油地震勘探测量中的工作方式,结合2007年度南盘江一桂中地区二维地震大剖面资料采集应用GPS的工程实例,介绍GPS技术应用的新进展。通过GPS静态测量和应用RTK技术放样物理点,从测前准备、数据处理、精度分析等方面,阐述提高作业精度、有效进行质量控制的方法,旨在最大限度地发挥GPS技术在山区施工中的作用。  相似文献   

四川汶川大地震的构造分析   总被引：6，自引：0，他引：6  

王振荣  兰江华 《矿物岩石》2008,28(2):1-5

2008年5月12日在汶川映秀(北纬31.0°,东经103.4°)发生8级大地震,而后发生万余次余震,其最大震级为6.4级.此次地震属主震-余震型地震.通过构造分析认为.汶川大地震是构造地震,主要受龙门山断裂带的强烈活动控制.它是一种板内地震,其动力来源来自印度板块与欧亚板块的碰撞.而成都平原处于稳定地块中,尽管离震中较近,然受地震的影响有限,是比较安全的.  相似文献   

"5.12"汶川大地震震中区映秀镇地震灾情及次生地质灾害遥感初步调查   总被引：4，自引：0，他引：4  

王治华  周英杰  徐斌  贾斌 《国土资源遥感》2008,(2):1-6

"5.12"四川汶川8级大地震发生后,中国国土资源航空物探遥感中心立即采用"赛斯纳"高空遥感飞机,携带高清晰彩色数码相机及先进的POS系统,迅速获取了重灾区的航摄图像数据。本文以震中附近的映秀镇地区为例,简要介绍了以该高质量航摄数据为基础,采用数字滑坡技术,快速进行震后重灾区灾情及次生地质灾害遥感调查的成果。  相似文献   

Using Topological Relationships to Inform a Data Integration Process   总被引：2，自引：0，他引：2  

Sue Hope  Allison Kealy 《Transactions in GIS》2008,12(2):267-283

When spatial datasets are overlaid, corresponding features do not always coincide. This may be a result of the datasets having differing quality characteristics, being captured at different scales or perhaps being in different projections or datums. Data integration methods have been developed to bring such datasets into alignment. Although these methods attempt to maintain topological relationships within each dataset, spatial relationships between features in different datasets are generally not considered. The preservation of inter‐dataset topology is a research area of considerable current interest. This research addresses the preservation of topology within a data integration process. It describes the functional models established to represent a number of spatial relationships as observation equations. These are used to provide additional information concerning the relative positions of features. Since many topological relationships are best modelled as inequalities, an algorithm is developed to accommodate such relationships. The method, based on least squares with inequalities (LSI), is tested on simulated and real datasets. Results are presented to illustrate the optimal positioning solutions determined using all of the available information. In addition, updated quality parameters are provided at the level of the individual coordinate, enabling communication of local variation in the resultant quality of the integrated datasets.  相似文献   

附加约束条件的序贯平差   总被引：1，自引：0，他引：1  

曾安敏  杨元喜  欧阳桂崇 《武汉大学学报(信息科学版)》2008,33(2):183-186

从观测量分组的参数平差出发,详细推导了附加约束条件的序贯平差及其精度估计,讨论了附加约束条件的抗差序贯平差的计算过程.算例表明,推导的公式正确有效,简单实用,附加约束条件的序贯平差抗差估计能有效地抵制粗差的影响.  相似文献   

斜坡非饱和带低渗透岩石结构体风化前锋扩展过程   总被引：2，自引：0，他引：2  

徐则民 《地学前缘》2008,15(4):258-268

非饱和带低渗透岩石结构体风化前锋扩展是斜坡灾害孕育过程中的关键环节之一。到目前为止,化学风化领域的研究成果主要集中在高水-岩比的饱和环境下单矿物及矿物成分单一的碳酸盐岩的风化动力学方面,非饱和环境下的岩石风化研究还主要限于风化产物的特性描述方面。斜坡非饱和带低渗透岩石结构体风化前锋扩展是一种高度复杂的THMC过程。由于在溶解对象、溶解液及溶解过程的水动力-水化学环境等方面存在的显著差异,既有的地质材料风化动力学成果为探索这一复杂过程提供了理论储备,但还不能阐明其核心机理。斜坡非饱和带低渗透岩石结构体风化前锋的扩展过程研究不仅可以加深人们对斜坡灾害孕育的理解,为灾害预报-预警及其控制提供理论依据,同时可以促进岩石-岩体力学及浅表生水文地球化学等相关学科的交叉与发展。  相似文献   

汶川特大地震后成都盆地内隐伏断层活动性分析   总被引：5，自引：1，他引：4       下载免费PDF全文

董顺利  李勇  乔宝成  马博琳  张毅  陈浩  闫亮 《沉积与特提斯地质》2008,28(3):1-7

成都盆地内主要有3条隐伏的活动断裂带,包括大邑断裂带、蒲江-新津断裂带和龙泉山断裂带,它们在第四纪都表现出了一定的活动性."512"汶川特大地震后,笔者实地考察的结果表明,在汶川特大地震中成都盆地中的隐伏断裂没有产生新的活动性,目前成都盆地不存在发生特大地震的危险性,是安全的.  相似文献