用顶升法检测轴系安装的质量

介绍了在轴系按校中计算安装后,通过顶升法检测轴系中轴承所承受的负荷,来检查轴系安装是否正确。并结合顶升法在1000TEU船上的应用实例,对其进行阐述。     

CJ46自升式钻井平台总体布置的优化设计

针对CJ46自升式平台总体布置中通道不合理、生活楼薄板变形、作业效率不高、适用性不强等问题分析原因,结合规范法规要求,综合优化制定相应的解决方案,重点对脱险通道、泥浆池、钻台面、生活楼、飞机平台和潜水泵塔等关键区域进行综合优化改进,提高了钻井作业的效率和适用性,大幅提升了市场竞争力,亦可为其他类型的自升式钻井平台设计提供参考。     

自升式平台桩腿海上对接过程中的碰撞问题

碰撞现象在海上作业中时有发生,给人员和财产安全带来极大威胁。本文基于非线性有限元理论,研究自升式平台桩腿吊装过程中浮吊船与平台的碰撞问题以及桩腿移动就位时对平台上层建筑的碰撞问题；分析撞击过程中平台的变形与应力变化及结构失效等情况,给出使平台不同区域发生破坏的临界碰撞速度；给出了浮吊船在就位过程中的安装制动距离以及移动过程中与上层建筑间的安全距离和移动速度限制,为桩腿海上吊装作业方案设计提供参考。     

海上吊物六自由度系统动力学特性分析

自升式风电安装平台由于作业臂长度的限制,在进行海上钻井和维修作业时会紧靠导管架平台。风电安装平台桩靴插桩过程中会排开大量土体,对临近平台桩基产生很大的挤压荷载。以某自升式风电安装平台和其临近固定平台为研究对象,探讨了风电安装平台桩靴入泥带来的挤土荷载与环境荷载的耦合作用对平台桩基强度的影响。分析结果表明,在靠近泥面一定范围之内,在进行导管架钢桩设计时必须考虑挤土荷载与环境荷载的耦合作用,以满足导管架平台桩基强度要求。     

The weldability of steels used in jack-up drilling platforms

Weldability problems in jack-up rigs arise principally in leg construction where particularly high-strength steels (690 N mm⁻² yield) are used for chords and racks. Attainment of mechanical properties is not usually difficult, although procedural trials are advisable.

Of potential fabrication problems, hydrogen cracking (heat-affected zones or weld metal) is of greatest concern, and consideration of solidification cracking is advisable. Lamellar tearing is not generally a problem with modern steels, and the risk of stress-relief cracking will be confined to the limited number of joints which can be heat-treated.

Fatigue cracking is probably the major cause of service failure of jack-up rigs, and the use of high-strength steels, which permits higher static stress limits, can exacerbate this problem. Hydrogen-induced stress corrosion can also occur, either due to cathodic polarisation or corrosion, particularly in the presence of H₂S in foul sea-water. For this reason weld hardness limits need to be maintained.     

Collision damage of jack-ups

North Sea collision accident records covering a period of ten years indicate that the risk of collisions involving jack-ups is not dissimilar to that for semi-submersibles or fixed jacket structures. However, jack-ups are much more flexible than jackets and have a much lower degree of redundancy. Their response to collisions and their ability to absorb impact energy is, therefore, expected to be considerably different in comparison to jackets. This paper examines available data and information regarding the capability of jack-ups to withstand collision impacts and investigates the level of local damage that can potentially be caused to jack-up legs due to accidental collisions.     

某自升式平台升降系统结构强度评估

以渤海自立号沉垫自升式平台为评估对象,采用检测、测厚和建模分析等方法对平台升降结构强度进行评估,得到升降结构允许单桩最大起升能力和受力最大位置,为延长升降系统的安全使用寿命提供理论依据。     

某预应力混凝土曲线连续箱梁桥加固

某预应力曲线连续箱梁桥,在施工支架拆除后,过渡墩圆曲线内侧支座脱空2cm,中间固结钢管混凝土墩向圆曲线外侧偏6.4cm,通过加固满足了桥梁安全和使用性能的要求。分析问题出现的原因,介绍切实可行的加固方案,可为有类似问题桥梁的处理提供一定的参考。     

基于不中断交通的桥梁支座更换技术研究

结合江阴大桥北引桥支座更换维护项目,采用SPLC-8计算机控制的液压整体同步顶升技术进行桥梁支座的更换施工。对不中断交通条件下的整体同步控制技术、顶升方案、施工工艺、支座更换施工以及施工中的关键性问题等进行了分析与探讨,工程实践表明在不中断交通状态下采用SPLC-8计算机控制的液压整体同步顶升技术进行桥梁支座更换是可以实现的。     

Extreme-response analysis of jack-up platforms

The extreme wave and current response of a typical North Sea jack-up drilling platform has been calculated using nonlinear, stochastic, time-domain analysis techniques. A statistical treatment of the response-time histories has been performed. Appropriate probability distributions have been fitted to simulated response amplitudes and extrapolated to determine extreme values in storms of 3 or 6 h duration. Nonlinear geometric effects and dynamic effects are also addressed.

The results of the nonlinear time-domain analyses are compared to the results of more simplified methods used in jack-up designs.