封一/四

为了解决FRP筋弹性模量低、剪切强度低和延性差的问题,设计和制备了多种规格的FRP-钢筋复合筋,并通过拉伸和剪切试验研究了含钢率和直径对其拉伸性能和剪切性能的影响。然后根据FRP-钢筋复合筋的性能特点及其增强混凝土构件的性能要求,提出了此类构件与相同钢筋混凝土构件的配筋总刚度相等的等效刚度设计法,并试验对比和分析了等承载力与等效刚度2种不同等效设计法设计的FRP-钢筋复合筋增强混凝土梁的受弯性能。结果表明:与FRP筋相比,FRP-钢筋复合筋的弹性模量、延性和剪切性能都明显提高。FRP-钢筋复合筋的弹性模量可达到FRP筋弹性模量的3倍以上,这为等效刚度设计法的实现提供了良好基础。等效刚度设计的FRP-钢筋复合筋增强混凝土梁具有和钢筋混凝土梁接近的屈服前受力性能(挠度和最大裂缝宽度)和良好的延性,并且可使其极限承载力提高30%。即等效刚度设计的此类构件不仅可满足安全性和适用性要求,而且具有更大的承载力储备和更好的耐久性。由于等效刚度设计法可参考现有的钢筋混凝土结构设计规范进行设计,其有望为此类构件和结构设计与工程应用提供简便适用的计算分析和设计方法。     

基于FRP-OFBG复合智能筋的基桩内力监测

桥梁深水基础的基桩是整桥的重要组成部分,其受力状态是评价基础工程乃至整桥安全性的关键指标之一.本文以南京长江第三大桥南塔基桩受力计算及分析为基础,选择群桩中的2根边桩作为监测对象并确定出合理的监测断面.为克服传统传感器在抗干扰能力及寿命方面的缺点,尝试采用纤维增强塑料封装的光纤布拉格光栅应变传感器.监测结果表明:传感器布设工艺可靠,基桩内力量测值合理,且承载力余量尚大.     

斜拉索磁流变智能阻尼控制系统分析与设计

在结构主动、半主动和智能控制系统优化设计方法的基础上,研究了斜拉索磁流变智能阻尼控制系统的设计方法,并采用所建立的设计方法完成了山东滨州黄河公路大桥斜拉索磁流变智能阻尼减振系统的优化设计。采用限界HROVAT最优控制算法确定磁流变阻尼器的半主动控制力,数值计算了斜拉索磁流变阻尼控制系统的风振反应。进一步分析比较了主动控制、半主动控制、Passive-on被动控制和Passive-off被动控制策略下的磁流变阻尼器控制斜拉索风致振动的控制效果,验证了磁流变阻尼器优化设计方法的正确性和磁流变阻尼器控制策略的有效性。     

具有粗砂层的FRP板与混凝土粘结性能试验研究

纤维增强复合材料板与混凝土的有效粘结是保证FRP-混凝土组合结构正常工作的基础.采用FRP板-混凝土块搭接接头的单剪试验方法研究FRP板与混凝土的粘结性能,为增强粘结效果,对FRP板表面采取了粘结粗砂的措施,试验同时考虑粘砂长度对粘结性能的影响.试验结果表明:(1)粘结破坏为典型的脆性破坏;(2)平均粘结强度与粘砂长度近似成反比;(3)粘结粗砂法可作为FRP-混凝土组合结构中有效的组合界面连接措施.提出的抗剪设计方法可用于FRP-混凝土组合结构中组合界面抗剪设计.     

东营黄河公路大桥振动监测系统设计与实现

振动监测系统是桥梁健康监测系统的必要组成部分。详细论述东营黄河公路大桥振动监测系统中加速度传感器子系统、数据采集及传输子系统、数据在线分析子系统、数据存储与管理子系统的设计与实现中的关键技术问题,可为同类桥梁振动监测系统的建立提供有益的借鉴。     

Analysis of Key Factors in Cable Force Calculation for Cable-Stayed Bridges

Three methods for calculating cable force (analytic method, fitting method and finite element method) are analyzed and compared. The effects of boundary condition, spectrum resolution, sampling time, and number of sampling points on the precision of cable force identification are discussed, and error analysis is conducted. The results of three methods applied to a practical project are significantly less than the design value. Comparatively, the result of finite element method is the closest to the design value. Moreover, their computational precision and error are compared and analyzed. The precision of frequency identification of cables, long cables in particular, is strongly affected by frequency resolution. If the frequency resolution is included in calculating the cable force, the identification error can be reduced greatly.     

一新型深吃水平台的概念设计(英文)

The authors analyzed requirements for a new deepwater platform, from conceptual design to hydrodynamic analysis. The design incorporated Deep Draft Multi-Spar (DDMS) that allowed easy fabrication, reduced costs, and provided favorable motion performance. It also provided a dry tree system and other benefits. The conceptual design process included dimension estimation, general arrangements, weight estimation, weight distribution, stability analysis, etc. A high order boundary element method based on potential theory and the modified Morison equation was used to predict the hydrodynamic and viscous effects of this new concept platform. The response amplitude operators (RAOs) were acquired and compared with those of a typical Truss Spar. The response of the platform to the JONSWAP spectra of 3 different extreme ocean conditions was analyzed to evaluate the seakeeping ability of the new concept. The results revealed favorable motion performance due to all the degrees of freedom available.     

深吃水多立柱式平台的运动响应分析

提出了一种新型深吃水多立柱式平台DDMS(Deep Draft Multi-spars),介绍了DDMS平台的创新概念,并描述了平台的交互式设计方法和设计流程。使用基于绕射和辐射理论的高阶边界元方法,得到了平台波频激振力和水动力系数,在频域获得了幅值响应算子RAO。利用平均波浪漂移力和Newman近似方法预报了平台的二阶波浪慢漂激振力,在时域进行了DDMS平台运动响应的数值模拟。计算结果验证了DDMS平台设计的合理性,显示了平台良好的运动性能。     

Wave Forces and Moments on a Gravity Pier Foundation

In order to understand the wave forces and moments on a gravity pier foundation which consists of an upper column and a bottom gravity base,a model experiment with a scale of 1:60 has been conducted in a laboratory flume.A corresponding numerical calculation by using the boundary element method has been carried out to provide a comparative analysis.It is shown by the comparisons that the numerical wave forces and moments agree well with the experimental results.It is proved that the wave forces and moments acting on the foundation are completely in their inertia dominative areas for wave loads.With the diffraction effects considered into the inertia item,appropriate inertia coefficients are assessed by the experimental results for the inertia item of the Morison equation.The formula of the inertia item can be used to estimate wave forces and moments on such gravity foundations.     

深水悬链复合锚泊线疲劳损伤计算

以某座Spar平台的锚泊系统为研究对象,首先利用三维绕射理论计算Spar平台主体波浪力,得到平台的总体运动响应时程。再建立复合锚泊线的二维非线性有限元动力分析模型,基于DelVecchio(1992)提出的经验公式,采用迭代的方法计算复合锚泊线的刚度。锚泊线和海床之间的接触作用基于刚性海床假定,基于Morrison公式计算锚泊线的惯性力和拖曳力荷载,根据计算得到的平台主体运动响应时程作为锚泊线顶端输入条件,在时域范围内进行复合锚泊线的动力分析。计算得到中国南海某海域各短期海况条件下复合锚泊线应力的时间历程曲线,采用雨流法对其计数得到对应于各短期海况条件下的疲劳载荷谱。最后根据Miner线性累积损伤模型,对复合锚泊线在长期海况条件下的疲劳损伤进行比较计算。