大型门式起重机安装施工技术分析

龙门起重机作为造船厂的主要支撑设备,对跨度,起升重量和起升高度都有很高的要求。本文结合大连华锐重工2台600 t-57 m通用门式起重机项目实例,分析了龙门起重机安装施工过程步骤,为龙门起重机的施工提供参考。     

关于桥梁现浇盖梁施工方法的探讨

盖梁是钢筋砼筒支梁桥中下部结构的主要受力构件,是梁板的支撑平台,盖梁-般设于墩柱顶部.本文介绍了包箍挑架式、预留托架式两种无支架现浇盖梁施工方法.     

武都高架特大桥双幅双柱整体式盖梁施工方案

本文介绍了双幅整体式盖梁采用"托架法"施工,不设支架,托架支点采用"抱箍"法施工的工艺.     

桥梁工程独柱低墩盖梁施工托架的设计与计算

阐述了在特殊情况下独柱低墩盖梁采用托架施工方案的确定,并结合工程实例,介绍了独柱低墩盖梁托架的整体设计及各杆件的设计计算方法.     

托架体的有限元分析

本文应用SolidWorks软件的有限元分析模块COSMOSWorks，对托架体进行了应力、应变和位移分析，并通过应力分布图、应变分布图和位移分布图分析最大应力、应变、位移发生位置，为托架体的开发提供了设计依据。     

天桥桁架梁悬索吊装施工技术

介绍了平邑站人行天桥桁架梁采用悬索配以吊机吊装的施工技术.     

FPSO搭载过程中的脚手架布置

FPSO液货舱舱壁上安装脚手耳板,再安装预制的脚手支撑托架来搭设工装脚手;在甲板反顶安装脚手吊环,再安装挂钩,搭设悬挂脚手,从而只需要在结构装焊以及舾装作业面,搭设脚手.相对于扣件式钢管脚手架的常规搭设方法,采用本文所提出的工装脚手搭设方法来搭设液货舱脚手架,可节省大量的脚手架搭设工程量和搭设时间.     

屯门拍案称奇

今年元宵节前夕的2月19日晚，香港屯门内河码头发生了一起离奇劫案。据香港媒体报道：5名计划周详的海盗，深夜乘船如入无人之境，直闯屯门海面，摸黑潜登载有货柜的趸船。5海盗分头行动，先将船上电源截断，再将看更杀个措手不及。海盗操作吊机只花了20分钟，将7个载有各式各样货物的货柜运走，神不知鬼不觉乘船离开。香港媒体说，劫匪出动吊机将货柜整个搬走，罕有所闻。     

拱板仓拱板伸缩缝的气密处理

针对拱板仓拱板间伸缩缝的密封处理问题,介绍了几种拱板伸缩缝的处理方法.     

片岩地区隧道塌方原因分析及处理

以某高速公路白鹤隧道施工为例,针对白鹤隧道YK92+818～YK92+825段的塌方事故,分析了片岩地区隧道塌方发生的原因,提出了相应的应急处理措施,确定了设置临时支撑进行加强初期支护和浇筑混凝土护拱通过塌方的综合处理方案。同时,通过工程实践对该综合处理方案处理效果进行了评价,证明了该方案的可行性。     

青海省天峻县龙门地区钨多金属矿找矿前景分析

从地质、物探、化探等方面对青海天峻龙门地区的钨及多金属矿找矿前景做初步分析。区内出露地层主要为志留系巴龙贡噶尔组杂砂岩、云母石英片岩夹板岩、凝灰质板岩和少量中性火山岩．断裂构造主要为一组北北东向断裂．侵入岩主要为基性一超基性岩及隐伏的酸性花岗岩。1：5万水系沉积物“龙门HS49”综合异常显示W、Bi、Mo等元素有不同规模的明显异常,且W异常规模最大。通过土壤化探测量可以得知化探异常与物探异常重叠较好。磁异常显示该区是热液成矿的有利部位．为这些金属矿的深部找矿预测提供了有利证据。     

浅谈桥架式起重机安全性能的改善

随着现代电气设备的不断进步和发展，方便、安全的节能产品相继面世，安全生产依旧是考虑的关键。桥架式起重机由于具有起重灵活、操作简单、装卸转移运输方便等特点被广泛应用。因此确保桥架式起重机的安全运转，可以提高工作效率、降低生产成本、防止人身伤亡、树立良好的企业信誉。然而由于种种原因，桥架式起重机在使用过程中会出现各种事故，给施工企业造成不必要的损失。本文主要介绍了桥架式起重机安全性能上的缺陷性能特点及不足之处，并提出改进的方法和行车改造后的使用情况。     

制动器拉杆断裂的原因及对策措施

通过对门机起升制动器拉杆断裂现象的分析，提出解决方法、对起升制动器拉杆进行改造，消除门机由于拉杆断裂引起的故障，减少了停工损失。     

浅谈旋转变频液压推杆制动器在港口门机上的应用

随着近几年港口生产的发展，门座式起重机的应用不断增加，而且逐步向大吨位门机25t以上的方向发展。本文详细阐述了变频液压推杆制动器在门机中的应用，不仅减小了劳动强度而且节约了维修成本。     

吊车系统的输入整形防摆控制

本文针对传统吊车防摆闭环控制方法存在的控制器设计复杂、控制效果不理想、不易实现等问题,提出了一种经典控制理论与前馈输入整形技术相结合的控制技术。首先,对吊车系统进行建模并简化数学模型,采用经典控制理论设计吊车的伺服控制系统。其次,引入输入整形技术设计吊车系统的ZV输入整形器。最后,通过MATLAB仿真验证所提出控制技术的有效性。     

Möglichkeiten zur Kompensation der kalten Progression: Wirkung in Österreich

Regardless of the latest tax reform the fiscal drag brings an additional tax burden of € 6.2 billion for the period 2016-2021 to Austrian taxpayers. In 2021 alone this fiscal drag will levy an additional € 2.17 billion. The study in hand gives an overview how other countries control the fiscal drag and analyses the effect of such adjustments in the Austrian tax system. Depending on the adjustment model, the range of the fiscal drag by 2021 lies between a tax burden of € 4 billion (tax brackets adjusted once the cumulative inflation reaches the 5 percent threshold) and between a tax reduction of € 1.6 billion (the tax system is adjusted to the development of nominal wages). In the latter case an adjustment leads to an over-compensation of the fiscal drag yielding a constant tax burden relative to income. For the entire elimination of the fiscal drag an annual inflationary adjustment of the tax brackets, tax credits and deductibles is necessary.     

液压助力式动力转向系统的故障诊断与排除

本文以大中型起重机搬运机械为例,介绍了液压助力式动力转向系统常见的故障诊断与排除方法.     

The Relationship between task complexity and information search: The role of self‐efficacy

Prior research suggests the complexity of a product choice task is inversely related to the extent of consumers' external information search. The resource‐matching perspective holds that cognitive effort (e.g., external information search) is greatest when available cognitive resources (e.g., as determined by self‐efficacy) match the cognitive demands of a task (e.g., perceived task complexity). Within a brand‐choice context, the relationship between self‐efficacy and extent of information search appears nonmonotonic. In support of the resource‐matching perspective, consumers conduct the most extensive information search when their self‐efficacy matches perceived task difficulty. © 2007 Wiley Periodicals, Inc.     

Modelling safety of gantry crane operations using Petri nets

Being a powerful tool in modelling industrial and service operations, Petri net (PN) has been extremely used in different domains, but its application in safety study is limited. In this study, we model the gantry crane operations used for industrial activities using generalized stochastic PNs. The complete cycle of operations of the gantry crane is split into three parts namely inspection and loading, movement of load, and unloading of load. PN models are developed for all three parts and the whole system as well. The developed PN models have captured the safety issues through reachability tree. The hazardous states are identified and how they ultimately lead to some unwanted accidents is demonstrated. The possibility of falling of load and failure of hook, sling, attachment and hoist rope are identified. Possible suggestions based on the study are presented for redesign of the system. For example, mechanical stoppage of operations in case of loosely connected load, and warning system for use of wrong buttons is tested using modified models.     

大跨度空间结构拱形基础底面尺寸的确定

结合工程设计实例,简要阐述空间结构拱形基础的简单计算,给初次设计者提供简便的设计手法,增强其对拱形建筑的理解,为以后复杂的基础结构设计打下良好的基础。