某立交桥加固改造设计与施工

某立交桥为7跨20 m预应力空心板简支梁桥,运营多年后发现主梁整体性不足,单梁受力状况突出,桥面板出现纵向开裂等病害,同时桥墩盖梁出现弯曲裂缝,侧向挡块破损严重。针对病害情况,确定采用外包钢板加固盖梁、钢-混组合梁替换旧桥部分薄弱梁体、中部三跨由简支到三跨连续的结构体系转换等方法对桥梁进行加固改造。加固改造设计验算结果表明：加固改造完成后的桥梁承载能力能够满足目前的设计需求,具备较高的安全储备。加固改造施工时,采用人工配合风镐拆除旧桥桥面板,吊除梁体;按照设计的加固位置采用外包钢板加固盖梁;钢-混组合梁施工采用先吊装单根钢梁、后吊装横向联系梁的方案;按施工工序进行钢-混结合部和桥面铺装施工。该桥加固改造完成后桥梁运营状况良好。     

基于 Matlab PDE 工具箱的土体冻结温度场模拟研究

分析并运用Matlab PDE tool模拟模型槽土体冻结的温度场并验证模拟值的准确性。首先,通过合理的边界假设,使三维的模型槽土体冻结热传导问题转化为二维空间;然后,运用Matlab PDE tool进行模拟并对比测温点的模拟温度和实测温度。结果表明：土体冻结中温度场导热可以通过Matlab PDE tool模拟,且操作简单易于掌握;测温点模拟值的准确性与测温点距边界距离和冻结时间有关。     

创和谐交通为“宜居、宜业、宜游”服务

党的十七大做出了全面建设小康社会的战略部署．河北省也开启了沿海混省建设的新征程．秦皇岛市的发展正站在新的历史起点上。当前和今后一个时期．市政府要求认真贯彻党的十七大精神,全面落实科学发展观,重视改善民生和促进社会和谐,以构建富庶文明和谐、宜居宜业宜游新秦皇岛为总目标,全面推进以实力、活力、魅力、竞争力为标志的沿海强市建设。同时提出要以人民利益为根本价值取向．     

造价分析在工程审计中的应用

路工程造价的合理有效控制是工程建设管理的重要组成部分,搞好工程审计对降低项目成本非常重要,更积极的意义是合理的使用人力、物力,财力,以取得最大的投资效益。本文从实践经验出发对公路工程审计中的造价分析方法进行了简要总结,为更好地开展此项工作提供借鉴。     

双车道公路运行速度计算与安全性评价方法研究

基于对双车道公路车辆运行速度的观测和行驶特性的分析,研究并提出双车道公路运行速度计算方法和预测模型.通过对国内外公路行车安全性评价标准的比较研究,提出以速度变化率为主的双车道公路安全性评价标准与评价方法,以填补我国《公路建设项目安全性评价指南》在这方面的空白.实际应用表明其评价结论较为可靠.     

Experimental study on mechanical properties of weathered rock covered by loess

Based on dynamic triaxial test, the mechanical properties of the weathered rock covered by loess were studied. The cohesion value of weathered mudstone is far below that of the weathered sandstone, while the internal friction angle values are basically equivalent, about 30°. Compared with the undisturbed sample, the cohesion value of remodeling weathered rock sample decreases significantly. With the increase of moisture content, the strength of weathered mudstone is obviously decreased due to the influence of the water softening effect. This results illustrate that the bearing stratum is not easily affected by external disturbance in comparison to weathered mudstone. In the engineering, in order to ensure the good mechanical properties of the soil, more attention should be paid to keeping the water content constant, even to reducing the water content. The experiments show that the relations between shear stress and strain of weathered rock were nonlinear and the behavior of weathered rock can be expressed by the hyperbolic model. The initial modulus of undisturbed weathered rock, under the same consolidation conditions, is much greater than that of remodeling samples. Meanwhile, the initial dynamic elastic modulus of sandstone is also greater than that of the mudstone. The dynamic shear modulus ratios of the undisturbed sandstone, the undisturbed mudstone, as well as the remodeling mudstone have the normalization characteristics with the increase of dynamic shear strain. The damping ratio of mudstone is larger than that of the sandstone, and the damping ratio of remolding sample is also greater than that of the undisturbed mudstone. The mudstone has the bad mechanical properties as bearing stratum.     

汽车智能座舱多屏互动方案

一机多屏设计已逐渐成为智能虚拟座舱系统的重要组成部分,同时也是科技感和优质体验的一种外在表现形式。近年来车内屏幕类型越来越多,而车内多屏交互设计也成为未来汽车设计的一种趋势。本文首先介绍常见的多屏互动场景,然后深入探讨娱乐交互系统软件架构,最后提出多屏互动实现方案。     

地铁供电接触轨检测尺校准装置

目前国内尚无适用于地铁供电接触轨检测尺的专用校准装置。为此,基于接触轨检测尺实际应用场景,研制一种接触轨检测尺校准装置。介绍接触轨检测尺校准装置组成和校准步骤,评定校准装置测量不确定度。评定结果表明,接触轨检测尺校准装置扩展测量不确定度为0.32 mm,小于接触轨检测尺最大允许误差的1/5。该校准装置计量性能满足量值溯源要求,可用于校准接触轨检测尺。     

一位海军舰长的海上经历——访海军厦门部队副司令员丁锦大校

当一名海军舰长,驾驶威武雄壮的军舰在辽阔的大海骋驰邀游,是不少青少年读者心中的梦。一旦圆了少年梦的军人,海上生活会是怎样呢?日前,记者访问了曾任过海军扫雷舰、护卫舰舰长和驱逐舰副长的丁锦海军大校。今年44岁的丁锦已在海上生活战斗了26年。这位来自浙