GIS技术在有线电视网络中的应用     

朱斌 《物探化探计算技术》2005,27(2):160-162

一个现代化大城市的有线电视网络是十分庞大复杂的,为了对有线电视网络资源进行有效管理和维护,利用地理信息系统(GIS)的网络规划设计管理等功能,建立有效的有线电视网格信息系统是十分必要的。在这里,以有线电视网为背景,讨论了地理信息系统的发展现状,地理信息系统的组成,GIS系统在有线电视网络管理中的必要性和优越性。针对有线电视网络的特点,描述了有线电视GIS综合管理系统的模块功能,如系统资源管理、信息查询等内容。  相似文献   

VC++调用Matlab实现三维欧拉反褶积运算   总被引：1，自引：0，他引：1  

张浩平  付媛媛 《物探化探计算技术》2006,28(2):178-181

磁性地质界面的反演是地球物理勘探的重要方法之一。这里介绍了在V isual C 6.0调用Matlab engine的详细步骤,实现了以VC为主界面,调用Matlab反演磁性界面的三维欧拉算法,并应用到不同延深的单体模型和多体模型实验中。结果表明,程序的开发周期和工作量大为缩短,复杂分布的磁性体也可用该方法确定水平位置和深度。该程序为开发地球物理分析软件提供了一条高可靠性、低开发周期的有效途径。  相似文献   

Magnetic Detection Method for Seabed Cable in Marine Engineering Surveying     

YU Bo LIU Yanchun ZHAI Guojun BIAN Gang XIAO Fumin 《地球空间信息科学学报》2007,10(3):186-190

The detection and identification of the seabed cable is becoming an important task in the marine engineering. The features of the magnetic anomaly can be used to detect the existence of the seabed cable. The magnetic field model is presented, and the consistency of the magnetic anomaly distribution between the simulation of the model and the observed data is verified. The comparison shows that the seabed cable can be effectively detected and identified with reasonable method.  相似文献   

超弹性-复摩擦摆隔震支座的性能试验与数值模拟          下载免费PDF全文

庄鹏  王尉  韩淼 《世界地震工程》2022,38(1):099-109

利用复摩擦支座（Double friction pendulum bearing,DFPB）和形状记忆合金（Shape Memory alloy,SMA）拉索,提出了一种超弹性-复摩擦支座（Superelastic-double friction pendulum bearing,SDFPB）。该新型滑动隔震支座在水平方向可适应多水准地震激励,且在竖向拥有抵抗拉拔的功能。阐述了SDFPB的构造特点和工作原理。通过性能试验考察了这一隔震装置的力学特性。建立了SDFPB的恢复力模型,利用其模拟了试验条件下的滞回响应。研究结果表明:SDFPB的耗能能力优良,且具有较好的多级抗震自适应能力;模拟值与试验值吻合较好,验证了上述力学模型的正确性。  相似文献   

悬索桥主缆架设测量方法与误差修正     

葛文  黄腾  欧乐  朱春宁 《测绘与空间地理信息》2015,(7):220-224

分析了悬索桥主缆架设测量的主要误差来源,提出了几种相应的改进方法。在主缆基准索股架设测量过程中,综合考虑测量误差,采取反推仪器高法修正仪器高量取误差;垂度测量时,采用上下安装棱镜的夹具工装,即通过测上下棱镜的标高,取其平均值推算出基准索股垂度;一般索股采用改进的相对基准索股法进行测量调整。上述方法在实际应用中获得了较好的结果,能满足主缆架设测量的精度要求,可供类似桥梁工程借鉴。  相似文献   

A Geometrically Exact Formulation for Three-Dimensional Numerical Simulation of the Umbilical Cable in A Deep-Sea ROV System     

全伟才  张竺英  张艾群  张奇峰  田宇 《海洋工程》2015,29(2):223-240

This paper proposes a geometrically exact formulation for three-dimensional static and dynamic analyses of the umbilical cable in a deep-sea remotely operated vehicle (ROV) system. The presented formulation takes account of the geometric nonlinearities of large displacement, effects of axial load and bending stiffness for modeling of slack cables. The resulting nonlinear second-order governing equations are discretized spatially by the finite element method and solved temporally by the generalized- implicit time integration algorithm, which is adapted to the case of varying coefficient matrices. The ability to consider three-dimensional union action of ocean current and ship heave motion upon the umbilical cable is the key feature of this analysis. The presented formulation is firstly validated, and then three numerical examples for the umbilical cable in a deep-sea ROV system are demonstrated and discussed, including the steady configurations only under the action of depth-dependent ocean current, the dynamic responses in the case of the only ship heave motion, and in the case of the combined action of the ship heave motion and ocean current.  相似文献   

LOAD DISTRIBUTION ALONG FULLY GROUTED BOLTS,WITH EMPHASIS ON CABLE BOLT REINFORCEMENT     

A. J. HYETT  M. MOOSAVI  W. F. BAWDEN 《国际地质力学数值与分析法杂志》1996,20(7):517-544

Explanation for the widely reported observation that fully grouted reinforcement is more effective in hard rock that behaves as a discontinuum than in soft rock is presented. Analytical solutions are presented for the distribution of displacement and load along an untensioned fully grouted elastic bolt, of specified bond stiffness, which is activated during excavation by either a continuous or discontinuous distribution of rock displacement. The results indicate that significantly higher axial loads are developed for the discontinuous case. Since the mechanics of bond failure depend on the type of bolt and grout used, in the second part of the paper a finite difference formulation is introduced and combined with a non-linear model for the bond behaviour of a cement grouted seven-wire strand cable bolt. The results of a parametric study indicate that, because the bond is frictional and depends on confinement at the borehole wall, for the same profile of rock mass displacement lower loads are developed in soft rock. Furthermore, in soft rock, excavation induced stress changes can cause a dramatic reduction in bond strength, so that, even after significant rock mass displacement, the axial load developed is significantly less than the tensile strength of the cable. A combination of these effects can explain why failures of cable bolted ground involve debonding at the cable–grout interface in soft rock, and why instances of cable rupture are confined to hard, blocky rock masses.  相似文献   

锚索预应力初期与长期损失的预测模型研究     

徐毅青  邓绍玉  葛琦 《岩土力学》2020,41(5):1663-1669

采用预应力锚索加固边坡是一种切实有效的方法。考虑锚索预应力变化与坡体蠕变之间的耦合效应,建立两种耦合模型并推导模型的本构方程和有效预应力的变化公式。基于实际锚固工程的预应力监测数据,采用反分析方法得到坡体的蠕变参数,划分预测阶段后采用相应的理论模型,通过理论计算值与实际监测值的对比分析,验证了分段预测模型的合理性和准确性。研究表明：在预应力预测的全周期采用单一的耦合模型,随着时间发展产生的偏差也随之增大;弹性模型与广义Kelvin模型并联（H-K模型）预应力曲线下降较快,适用于预测锚索锚固初期的预应力损失;弹性体上并联广义Kelvin（H-2K模型）能更好地拟合锚索预应力的长期变化。合理的分阶预测能够准确地评价锚索预应力的损失变化,为及时采取措施以保证边坡的稳定与安全提供科学依据。  相似文献   

黄陵矿业集团矿工公寓楼基坑支护工程设计          下载免费PDF全文

王伟  樊亚萍  王腾飞 《探矿工程》2020,47(9):57-62

黄陵矿业集团矿工公寓楼基坑设计开挖深度837 m。南侧安全等级为一级,不具备放坡条件,设计采用排桩+预应力锚索格构支护方案;东、西、北三侧区段安全等级为二级,具备放坡条件,设计采用放坡+土钉墙支护方案;采用坑外管井降水+坑内集水明排组合降水方法。介绍了不同支护方案和降水方案的设计情况,同时介绍了土钉墙、支护桩、预应力锚索、降水井及观测井的施工技术要求。  相似文献   

Semiactive variable stiffness control for parametric vibration of cables     

李惠  陈文礼  欧进萍 《地震工程与工程振动(英文版)》2006,5(2):215-222

In this paper, a semiactive variable stiffness （SVS） device is used to decrease cable oscillations caused by parametric excitation, and the equation of motion of the parametric vibration of the cable with this SVS device is presented. The ON/OFF control algorithm is used to operate the SVS control device. The vibration response of the cable with the SVS device is numerically studied for a variety of additional stiffness combinations in both the frequency and time domains and for both parametric and classical resonance vibration conditions. The numerical studies further consider the cable sag effect. From the numerical results, it is shown that the SVS device effectively suppresses the cable resonance vibration response, and as the stiffness of the device increases, the device achieves greater suppression of vibration. Moreover, it was shown that the SVS device increases the critical axial displacement of the excitation under cable parametric vibration conditions.  相似文献