自升式可移动钻井船海管登平台技术

鉴于采用常规固定式平台进行浅海海洋石油工程开发周期长、经济门槛高的工程现状,本文创造性地提出采用自升式可移动钻井船并利用海底管道对新发现的构造进行快速开发,实现油气回收,同时考虑项目工期、成本和可操作性要求,以及自升式可移动钻井船水平位移大等难点,首次提出了“刚性立管+软管膨胀弯”的混合海管登平台方案,计算分析了其可行性,并与传统的“动态软管”、“刚性立管膨胀弯”和“软管穿护管”海管登平台等方案进行优缺点对比。该混合海管登平台方案不仅解决钻井船大位移技术挑战,而且利于国内采办,为今后类似边小油气田快速开发提供很好的借鉴作用。     

Real-time implementation of a traction control algorithm on a scaled roller rig

Traction control is a very important aspect in railway vehicle dynamics. Its optimisation allows improvement of the performance of a locomotive by working close to the limit of adhesion. On the other hand, in case the adhesion limit is surpassed, the wheels are subjected to heavy wear and there is also a big risk that vibrations in the traction occur. Similar considerations can be made in the case of braking. The development and optimisation of a traction/braking control algorithm is a complex activity, because it is usually performed on a real vehicle on the track, where many uncertainties are present due to environmental conditions and vehicle characteristics. This work shows the use of a scaled roller rig to develop and optimise a traction control algorithm on a single wheelset. Measurements performed on the wheelset are used to estimate the optimal adhesion forces by means of a wheel/rail contact algorithm executed in real time. This allows application of the optimal adhesion force.     

抛石挤淤结合强夯置换法在道路软基处理中的应用

以泉州市泉港区某道路采用抛石挤淤结合强夯法置换处理软基为例,阐述了软基处理方案的选择、设计与施工。采用钻孔揭露结合瑞雷波法对软基处理效果进行检测,通过计算校核检测结果,表明采用该方法处理软基科学合理,能满足工程要求。     

Fabrication and drilling tests of chemical vapor deposition diamond coated drills in machining carbon fiber reinforced plastics

Chemical vapor deposition (CVD) diamond coated drills are fabricated by depositing diamond films on Co-cemented tungsten carbide (WC-Co) drills. The characteristics of as-deposited diamond coatings are investigated by scanning electron microscope (SEM) and Raman spectra. To evaluate the cutting performance of diamond coated drills, comparative drilling tests are conducted using diamond coated and uncoated WC-Co drills, with carbon fiber reinforced plastics (CFRPs) as the workpiece on a high-speed computer numerical control (CNC) machine. Thrust force and tool wear are measured during the drilling process. The results show that diamond coated drill exhibits better cutting performance, compared with the uncoated drill. The value of flank wear is about 70 μm after machining 90 holes, about a half of that of theWC-Co drill with 145μm after drilling only 30 holes. The wear rate of WC-Co drill is higher than that of diamond coated drill before diamond films peeling off. The diamond coated drill achieves more predictable hole quality. The improved cutting performance of the diamond coated drill is due to the high hardness, wear resistance and low coefficient of friction.     

旋挖钻机施工工艺在城市人行天桥桩基施工中的应用

该文以广州市增槎路-水产批发市场人行天桥为例,介绍了旋挖钻机施工工艺在城市人行天桥桩基施工中的应用。该文结合工程的结构特点和地质情况,总结了旋挖钻机在钻孔灌注桩施工中的工艺和操作流程,并提出了旋挖钻机施工过程中的质量控制措施及注意事项,可为以后的城市人行天桥桩基施工提供参考。     

旋挖钻机在地铁三号线4标钻孔桩施工中的应用

通过旋挖钻机在广州市轨道交通三号线北延段4标钻孔桩施工中的成功应用,充分证实了旋挖钻机性能的优越,但也经常出现一些问题。根据经验总结成孔中的注意事项以及施工中经常遇到的不良现象和预防措施,以便于在以后施工中有针对性地采取对策,更充分发挥旋挖钻机的优势。     

隧道硬岩掘进经济成本对比分析

目前国内山岭隧道多数采用人工开挖,机械化、自动化水平低,不能满足隧道快速施工的要求。结合某隧道施工实践,介绍了人工开挖和双台车开挖机械设备配套、光面爆破技术,统计隧道开挖各工序的消耗时间,预估单台车开挖的时间消耗,并以此为基础详细分析、计算了各自施工成本组成,得出了台车开挖施工成本低,节约循环时间,更有利于快速掘进的结论。     

钻孔施工设备的新选择——旋挖钻机

本文介绍了钻孔灌注桩施工中的一种新设备。     

机车整车动态试验检测装置代替机车线路运行试验若干问题的探讨

阐述利用机车整车试验动态检测装置代替机车线路运行试验的必要性、可行性和发展过程。分析比较机车试验台轨道型式、轨道轮直径和黏着系数的适用条件。推荐机车试验台的试验内容和方法。     

桩基清除对周边环境影响的数值模拟分析

上海某轨道交通盾构顶进时下穿一高架桥梁,穿越断面与一桥梁桩基相交,因此须将影响盾构推进的桩基拔除.利用弹塑性有限元,分析全回转钻机清除桩基及孔洞回填对已建污水总管的影响,在预计的挤土效应内,污水总管的位移跟套管挤土位移基本呈线性关系,孔洞回填使污水管位移有所恢复,污水管最大位移在套筒挤土过程中产生.