斜拉桥塔壁锚固形式的环向预应力设计理论

斜拉桥的索塔锚固区受力情况较为复杂,在对该区域进行设计计算时,常采用实体建模计算结构各点的应力来评价结构的安全性,这种方法不仅繁琐,而且力学概念不清,往往不能得到最优结果。针对斜拉桥索塔锚固的塔壁锚固形式进行简化分析,研究了索塔锚固区环向预应力简化设计理论及其计算方法,该方法能够适应目前大多数斜拉桥的设计计算,具有较高的工程实用价值。     

混凝土预制块铺面接缝渗水特性试验研究

混凝土预制块铺面被广泛应用于城市人行道、小区、公园和景区路面铺装,预制块铺面存在大量不连续接缝,致使其渗水特性与传统的沥青路面和水泥路面有很大不同。针对混凝土预制块铺面接缝的渗水特性开展试验研究,研究接缝材料和接缝宽度对渗水系数的影响,实测不同类型接缝在不同时间段内的渗水量,在此基础上提出预制块铺面的设计渗水系数和渗水量计算方法。通过室内模拟降雨试验研究预制块铺面的排水特性,针对混凝土预制块用于高速公路紧急停车道提出典型的路面结构内部排水方案。     

厦漳跨海大桥北汊主桥抗震性能研究

厦漳跨海大桥北汊主桥是主跨780 m的连续钢箱梁双塔斜拉桥,场地地震基本烈度高达Ⅶ度,其抗震设计非常复杂,且无规范可循,为此开展专门研究.以JTG/T B02-01-2008《公路桥梁抗震设计细则》为指导,从抗震设防标准、地震动输入、动力有限元建模、抗震性能评价、抗震构造措施检查等方面,对厦漳跨海大桥北汊主桥抗震性能研究进行介绍,为类似桥梁抗震设计提供参考.     

简述采用城市快速干道开设施工便道减少工程环境影响

该文通过对上海某重大工程在城市快速干道开设施工便道的协调、优化,使施工便道得以顺利实施,为主体工程的建设带来便利的同时,大大减少了对工程环境的影响,取得了良好社会效益。其优化方案可供同行参考。     

站桥同位合建上盖钢箱梁“π”形支架门吊架设技术

为了解决繁华城区既有道路有限空间内快速、安全架设小半径曲线钢箱梁的施工难题,依托地铁车站柱网形式及围护结构冠梁为基础,采用高位门吊及"π"形支架体系架设方案,实现了在空间受限情况下,地铁车站、市政道路及高架桥三者的和谐统一。以合肥南北高架一号线Ⅰ标明挖地铁芜湖路站及其同位合建的上盖小半径反曲线钢箱梁为例,阐述站桥同位合建理念及"π"形支架联合门吊架梁方案,并对架梁支架及架梁对地铁车站的影响进行力学分析。得出以下结论:1)站桥同位合建共用一个走廊,既减少拆迁,又节约投资,为繁华城区有限空间立体开发提出了解决思路;2)利用下卧地铁车站柱网及桩顶冠梁,"π"形支架联合门吊架设,支架简单可靠、门吊快速安全,平行流水作业,安全、快速、经济,很好地克服了"S"形小半径反向曲线反超高的空间扭曲结构曲线拟合难、安全风险大的困难;3)"π"形支架支撑体系利用了下部车站柱网结构,能满足安全性要求。     

Using vehicle simulations to understand strategies for accommodating oversize,overweight vehicles at roundabouts

There is considerable evidence that roundabouts are the safest and most efficient form of traffic control for most intersections. The potential use of roundabouts with all their inherent benefits may be greatly diminished if they are not able to accommodate oversize/overweight (OSOW) vehicles, sometimes called “Superloads.” The problem, therefore, is how to accommodate OSOW vehicles without sacrificing the integrity, safety and other benefits of roundabouts.This study uses TORUS software to design six standard roundabouts using guidance from the latest Federal Highway Administration (FHWA) roundabout guide. Six OSOW check vehicles from the Wisconsin Department of Transportation’s library were used to modify the designs to accommodate these selected check vehicles at the roundabouts. These six OSOW check vehicles were used to conduct swept path analysis using AutoTURN software at the selected six standard roundabouts for right turn, through, and left turn simulations. The space requirements for these maneuvers were analyzed in detail. Various strategies for better accommodating these OSOW check vehicles were suggested and experimented with in this study using AutoTURN software simulations. The effectiveness of using a straight passage through the center island for OSOW vehicles was also addressed in this study and was found to be effective. All the strategies investigated in this study proved to be effective in accommodating OSOW vehicles when compared to conventional ways of using a roundabout. The needed total truck apron was calculated and used as a reference to determine an effective strategy for accommodating OSOW vehicles. This research can be used as guidance for transportation engineers, planners and decision makers to determine possible ways of designing a roundabout at an intersection where certain OSOW vehicles are expected.     

广东省道路客运同线经营的竞合分析

文中在简述道路客运的发展历史和未来态势的基础上，论述了道路客运从竞争走向合作所带来的增益，指出了从竞争走向合作的策略与措施。     

高等职业院校发展规划编制工作若干问题的思考

发展规划编制工作是高等职业院校实施战略管理的基础性工作,需要科学设计与统筹管理。本文梳理了高等学校战略规划的演进,分析了高职院校战略规划编制的过程模式,就发展规划编制工作的若干问题的有效解析提出了管理建议。     

Improvement actions for reducing transport’s impact on climate: A shipper’s perspective

The purpose of this paper is to compare improvement actions for reducing transport’s impact on climate from the shipper’s perspective. To that end, it introduces an evaluation tool for comparing improvement actions in transport systems in terms of transport costs, impact on climate, and barriers to implementation. Within the context of five international flows involving a food producer, three actions—namely, engaging intermodal transport, increasing load factors by double-stacking pallets, and using high-capacity vehicles—were evaluated. Shipment data were collected to calculate reductions in transport costs and impact on climate, whereas interviews with the food producer were conducted to identify barriers. Results showed that reductions in transport costs and impact on climate attributed to the improvement actions differed among the five flows. Engaging intermodal transport reduced the system’s impact on climate by 27–53%, double-stacking pallets by 0–23%, and using high-capacity vehicles by 7–15%, with differences primarily due to different freight densities. Concerning barriers to implementation, the improvement actions also varied by flow. Altogether, unlike other papers, which have examined improvement actions separately, this paper offers an evaluation tool for comparing several improvement actions at once, as applied to a particular empirical case. Shippers with multiple flows and several possible improvement actions can use the evaluation tool to efficiently reduce their systems’ impact on climate.     

基于LS-SVM算法和性能可靠性的航空发动机在翼寿命预测方法

以航空发动机的实际性能监测数据为基础,建立了时变性能退化模型,并进行了性能趋势预测。根据监测数据中大量与在翼寿命紧密相关的信息,分析了性能退化过程与失效分布函数之间的关系,得到了给定可靠度下的航空发动机在翼寿命。以航空发动机的实际在翼寿命为基础,利用K-S拟合检验方法对在翼寿命分布模型进行检验,采用最小二乘支持向量机确定了模型参数。结合性能退化趋势,计算了修正后的航空发动机在翼寿命,并以6台PW4000航空发动机为案例进行实例验证。分析结果表明:当正则化参数分别为25、37、28、40、27与35时,6台PW4000航空发动机的实际在翼寿命依次为6 921、7 160、7 820、8 490、8 498、6 921循环,对应的在翼寿命预测值依次为6 534、6 726、7 378、7 940、9 103、6 534循环,最大相对误差为0.071 190,最小相对误差为0.055 917,平均相对误差为0.060 824,可见,提出的方法可以很好地满足工程实际需要。