北仑电厂码头大管桩裂缝调查检测及修复加固方案设计

通过对北仑电厂码头大管桩的详细调查与检测,发现混凝土大管桩多处存在纵向裂缝和周向裂缝,直接影响码头混凝土结构的安全性、耐久性。在分析研究的基础上,对存在裂缝的大管桩提出合理的修复方案,为码头的安全运行提供保障。     

某火车站无站台柱雨棚钢结构设计

研究目的:根据某火车站在改建工程中站台雨棚要求无柱化,提高通透性、舒适性的特点,对该站台雨棚的设计进行研究。研究方法:结合现场条件,采用单跨全覆盖的建筑形式。主体结构平面为41 m×400 m,两侧仅设置落地支撑28个,结构内部不设支撑柱,采用空间结构分析软件进行结构计算的研究方法。研究结果:通过铁路站台雨棚首次采用螺栓球网壳和落地立体管桁相结合的空间结构受力体系的实践,提出了成功的设计经验和有针对性的细部构造措施。研究结论:无站台柱雨棚采用正放四角锥双层柱面网壳与落地管桁结构的综合受力体系,不仅可以合理地发挥杆件效用,而且还可充分地展现建筑效果。对于体形较大的结构,温度效应的影响十分显著,在设计过程中采取相应的处理措施能有效地改善结构在温度作用下的受力性能;结构中的细部设计也应用了合理的分析计算方法,确保了结构的安全适用。     

管道挂靠桥梁隐患的处治

针对公路桥梁大量管道挂靠的情况,分析其形成原因及处理不当的危害,并针对性地提出维修及处置办法、管理措施。     

李渡长江大桥主塔斜拉索套管测量定位技术

介绍重庆李渡长江大桥主塔斜拉索的套管定位测量技术及施工过程中减少测量误差的措施等。     

TB880E型掘进机应用研究

由铁道部出资7．3亿元购置的2台TB880E型掘进机，先后完成了秦岭特长Ⅰ线隧道、磨沟岭隧道、桃花铺1号隧道的掘进任务，累计掘进长度22162m。这2台掘进机自2002年工程完工后，维修、保养、存放至今。TB880E型掘进机的正常使用寿命应在8000台班左右，可以完成35～40km隧道的掘进任务。此文结合秦岭特长隧道、乌鞘岭特长隧道施工方案，对掘进机与钻爆法的优缺点进行对比分析，探讨TBM剩余寿命期的利用问题，以期为今后选择合理的隧道建设方案提供参考。     

圆柱形壳体上开大直径相贯圆孔的数控切割原理

对在圆柱形壳体上开大直径孔的数控切割原理进行了分析，主要是针对大直径开孔所涉及到的重要的空间几何关系和运动关系的计算，并介绍了DKK-1型大直径开孔数控火焰切割机的设计及实际使用情况。     

Multimode trip information detection using personal trajectory data

Handheld global positioning system (GPS) devices can serve as a new tool to collect an individual's trip information with advantages of low cost, accurate data, and intensive spatial coverage. Various machine learning algorithms have been explored to detected trip train information in previous studies; however, few of them focused on the evaluation and comparison of the performance and applicability of different models. Meanwhile, according to previous studies, car and bus mode detection is a thorny issue due to their similar travel characteristics, and algorithms still need to be well explored and improved to solve this problem. In this article, an innovative method is proposed to detect trip information, including trip modes, mode-changing time and location, and other attributes, from personal trajectory data. The method is a two-step process. A machine learning algorith-based module (including artificial neural network, support vector machine, random forests, and Bayesian network) is firstly used to identify walk, bicycle, and motorized trip modes (bus or car); we thoroughly compared the performance of these four algorithms. Then a second module, using critical points on the GPS trajectories, is further developed to distinguish car and bus mode, incorporated with GIS map information. Field test results show that the proposed machine learning models can all be applied for walk, bicycle, and motorized mode detection with high detection rates exceeding 90%; however, the algorithms work relatively poorly for bus and car mode detection, with results mostly below 75%. The proposed two-step method can greatly improve bus and car mode detection accuracy by 14–30%. As a result, the average mode detection rates for all the four modes are above 90%. Compared with mode detection results by using only the machine learning algorithm, the proposed two-step method has much better performance in both accuracy and consistency.     

专家PID控制方法在舰船动力装置控制中的应用

首先介绍了传统数字PID控制方法在舰船动力装置控制中的原理和应用情况,分析了传统数字PID控制方式的不足,在此基础上提出了一种专家PID控制方法,最后介绍了该方法在舰船动力装置控制中应用实效。     

美标抗震设计中钢管桩与上部结构连接的探讨

桩基与上部结构的连接形式一直是高桩码头设计中的重要一环。尤其是在码头抗震设计中,合理的桩与上部结构连接形式不仅能确保桩基与上部结构间力的有效传递,而且还能充分发挥结构位移能力,并对上部结构形成能力保护。我国桩基规范虽然对钢管桩与上部结构连接形式做了相关要求,但却没有提及具体的计算方法及地震作用下的设计要求。探讨美标抗震设计中几种钢管桩与上部结构连接形式。     

Accidents involving pedestrians with their backs to traffic or facing traffic: an evaluation of crash characteristics and injuries

This paper examines pedestrian anatomical injuries and crash characteristics in back‐to‐traffic and facing‐traffic crashes. Pedestrian crashes involving pedestrians walking along streets (i.e. with their backs to traffic or facing traffic) have been overlooked in literature. Although this is not the most frequent type of crash, the crash consequence to pedestrians is a safety concern. Combining Taiwan A1A2 police‐reported accident data and data from the National Health Insurance Database from years 2003–2013, this paper examines anatomical injuries and crash characteristics in back‐to‐traffic and facing‐traffic crashes. There were a total of 830 and 2267 pedestrian casualties in back‐to‐traffic and facing‐traffic crashes respectively. The injuries sustained by pedestrians and crash characteristics of these two crash types were compared with those of other crossing types of crashes (nearside crash, nearside dart‐out crash, offside crash, and offside dart‐out crash). Odds of various injuries to body regions were estimated using logistic regressions. Key findings include that the percentage of fatalities in back‐to‐traffic crashes is the highest; logistic models reveal that pedestrians in back‐to‐traffic crashes sustained more head, neck, and spinal injuries than did pedestrians in other crash types, and unlit darkness and non‐built‐up roadways were associated with an increased risk of pedestrian head injuries. Several crash features (e.g. unlit darkness, overtaking manoeuvres, phone use by pedestrians and drivers, and intoxicated drivers) are more frequently evident in back‐to‐traffic crashes than in other types of crashes. The current research suggests that in terms of crash consequence, facing traffic is safer than back to traffic. Copyright © 2016 John Wiley & Sons, Ltd.