皮带机铸焊结构滚筒断裂原因及制作改进工艺

港口生产中皮带机的改向滚筒经常发生断裂,影响生产,浪费人力物力,必须加以解决。阐述滚筒的结构,分析滚筒的受力情况和断裂原因。提出提高滚筒的刚度和强度,改进支撑点,改进滚筒制作工艺等措施。经过改造,滚筒使用寿命显著提高。     

4000A舰船用智能型框架断路器

4000A舰船用智能型框架断路器是近期研制开发的舰船用新产品,具有容量大、短路分断能力高、零飞弧、能实现智能化保护的特点,介绍该产品的结构特点、基本参数、技术性能及主要应用．     

海底隧道基岩突起段地层典型滚刀破岩实验研究

为制定高强度花岗岩基岩突起地层的盾构掘进方案,在汕头海湾隧道现场取回花岗岩岩样,测试出CAI值及元素成分,进行滚刀破岩实验,对比分析相同工况下48.26 cm（19英寸）2种典型盘形滚刀（镶齿和一般平刃）的破岩效果,研究48.26 cm（19英寸）一般平刃在不同推力和刀间距下的掘进参数变化情况。实验结果表明： 1）工程现场的花岗岩岩样Si元素平均含量为37.35%,CAI值为3.56~3.91,为高磨蚀性岩石; 2）相同工况下,一般平刃滚刀具有更高的掘进效率; 3）单把滚刀总推力为300 kN时,掘进速度为4.1 mm/min。     

沉箱式防波堤的稳定性分析

运用有限元方法和动力分析方法,对沉箱式防波堤在近破波作用下的动力响应进行了研究。在确定滑移位移和转角为防波堤的主要参考动力响应参量的情况下,对能够产生运动的滑移和摇摆两种运动形式进行了动力分析,并提出了滑移位移和转角随时间历程的变化趋势。     

破碎波对直立堤作用的实验研究(英文)

Breaking waves can have tremendous destructive impact on vertical walls,yet they are poorly understood.By using particle imaging velocimetry(PIV) technology and high-precision pressure transducers,actual breaking wave loads on vertical walls were studied.By simultaneously comparing the flow field structure and wave pressure,the mechanisms of breaking wave pressure could be analyzed.The probability distribution of the peak value of the first impact of a breaking wave was investigated.The results showed that the impact pressure p is mainly distributed in the range of 0.25-2.75 ρν 2,with the greatest possible probability at p/ρ v2= 0.75.     

An experimental study of wave-in-deck loading and its dependence on the properties of the topside structure

This paper concerns the largest and arguably the most threatening wave loading component experienced by a broad range of offshore structures. It arises when an incident wave crest exceeds the elevation of the underside of the deck structure, leading to direct wave-in-deck (WID) loading. The extent of this loading may be limited to the partial submergence of some of the lowermost deck beams, or could involve the large-scale inundation of the entire deck area. Either way, very large loads can arise which must be taken into account when assessing the reliability of the structure. In an earlier contribution Ma and Swan (2020) provided an extensive laboratory study exploring the variation of these loads with the properties of the incident wave. The present paper describes a second stage of this experimental study in which the variation of the WID loads with the properties of the topside structure is addressed. Specifically, it considers the porosity, position and orientation of the topside relative to the incident wave conditions, and seeks to explore both the variations in the maximum load and the loading time–history resulting from these changes.Given the highly transitory nature of a WID loading event, coupled with the fact that the problem is governed by flow conditions at, or very close to, the instantaneous water surface, the loading process is driven by an exchange of momentum from the wave crest to the topside structure. A recently developed WID load model, based on exactly these arguments (Ma and Swan 2020), is used alongside the laboratory data to provide a break-down of the load into its component parts. This provides an enhanced physical understanding of the resulting load time–history. The first part of the study is based upon an idealised generic topside structure, allowing a systematic variation in key parameters, particularly porosity. The second part addresses a realistic topside structure demonstrating the practical relevance of earlier work. Taken together, the analysis clearly establishes the importance of the topside porosity, clarifies the spatial effects associated with the evolution of a large ocean wave beneath the plan area of a structure and explains the unexpected occurrence of impact-type loading on topside structures having a high porosity. Most importantly, the paper highlights those properties of a topside structure which must be incorporated if the WID loads are to be accurately predicted.     

预应力混凝土T梁翼板断裂后的加固

结合颖河桥桥面断裂塌陷成洞等病害，在分析病害原因的基础上，对桥梁进行了加固。介绍利用老桥结构且不中断交通进行加固、新老构造结合的设计与施工及加固过程中保持原预应力混凝土梁受力平衡的加固方法。     

考虑开挖情况主动土压力计算

在挖方工程中,开挖面形状、开挖面角度直接影响到滑动面的形状和滑动面的计算参数。由于开挖的影响,滑动面可能发生在老填土或者新填土中,滑动面上的应力状态不是库伦主动状态,因而不能采用传统的库伦土压力理论计算主动土压力。探讨了不同情况下土压力计算参数的取值和计算方法,提出了建议。     

隧道掘进机刀具破岩综合试验台电气系统的研制

针对不同地质,为相应的工程配置不同材质的刀具,满足不同的施工需求,研制隧道掘进机刀具破岩综合检测试验台。详细介绍该试验台的电气控制方案。该方案以操作台和上位机组成电气控制系统,采用Profibus总线控制方式建立连接,通过比例阀,电磁阀等执行机构实现系统的精确控制。重点研究并介绍供配电系统、PLC控制系统、数据采集测量系统等的设计思路及能完成的试验结果。试验结果表明控制系统可靠、实用。