浅谈热拌沥青混凝土路面的压实

为了保证热拌沥青混凝土路面的压实质量，从合理进行沥青路面压实机械的选型和组合入手．阐述了压实作业的基本程序和要求。具体分析了路面接荐处以及特殊路段的碾压工艺和提高热拌沥青混凝土路面压实质量的关键技术。     

基于最大裂纹张口位移计算应力强度因子的方法研究

文章提出了基于最大裂纹张口位移计算I型应力强度因子的新方法,该方法适用于复合载荷(均匀拉伸和纯弯曲载荷组合)作用下的具有半椭圆表面裂纹的有限平板模型。首先,理论推导了具有埋藏裂纹的无限大平板受均匀拉伸载荷作用时应力强度因子与裂纹最大张口位移的对应关系,再应用有限元数值模拟技术,考虑了表面效应、模型尺寸效应及载荷形式的影响,然后基于有限元模拟结果,根据多元多次最小二乘法原理拟合出对应修正系数表达式,最终建立了复合载荷作用下有限平板裂纹尖端应力强度因子与最大张口位移的函数关系,实现了由容易获得的最大裂纹张口位移确定应力强度因子的方法。该方法避免了对裂纹尖端的应力场、位移场的分析,为实际应用中应力强度因子的获得提供了新的方法。     

Analysis of subway station capacity with the use of queueing theory

A new concept of subway station capacity (SSC) is defined according to the gathering and scattering process. A queuing network analytical model of station is created for calculating SSC, which is built by M/G/C/C state dependent queuing network and discrete time Markov chain (DTMC). Based on the definition and the analytical queuing network, a SSC optimization model is developed, whose objective function is to optimize SSC with a satisfactory rate of remaining passengers. Besides, a solution to the model is proposed integrating response surface methodology with iterative generalized expansion method (IGEM) and DTMC. A case study of Beijing Station in Beijing subway line 2 is implemented to verify the validity and practicability of the proposed methods by comparison with simulation model in different experiments. Finally, some sensitivity analysis results are provided to identify the nodes that have the greatest impact on SSC.     

道桥防水施工中路基面处理技术和管理的探讨

在道桥防水方面的工程建设中,路基面处理是否得当是道桥防水是否成功的关键,对道桥防水施工过程中路基面处理技术和管理问题进行探讨和研究.     

港口系泊船舶受风高度取值问题研究

根据现行规范中船型尺寸、排水量、受风面积、形状系数等船舶参数与船舶形状特性的关系,以及船舶照片与船舶本身符合比尺相似这一特点,搜集船舶图片及其相关资料并进行研究分析,得出船舶水面以上高度的计算方法以及相关参数。解决了JTS 144-1—2010《港口工程荷载规范》中未给出船舶水面以上高度取值方法带来的问题。     

三维近自由表面水翼升力线理论

文章将普朗特的升力线理论扩展到自由表面下的三维水翼升力分析问题。二维水翼升力计算采用奇点分布法,三维水翼升力采用普朗特的马蹄涡叠加法,得到了三维水翼升力线计算理论。并且都考虑了自由表面的影响。在算例中,针对不同的潜深和翼弦长度,给出了升力系数和潜深弗汝德数的关系。其计算结果与其他文献所给的结果相比吻合得很好。     

高桩码头设计中波浪力计算方法的探讨

透空式高桩码头上部结构与波浪相互作用的问题非常复杂,现行规范找不到计算依据。在无规范依据情况下, 高桩码头设计时一般采用《海港码头结构设计手册》中进行波对码头上部结构作用力公式进行计算。根据设计手册相关 公式,提出了采用AutoCAD制图软件绘制理论波面的图形计算方法。并通过在AutoCAD中调整波面与码头结构断面相对位 置,分工况计算了某工程实例,供工程设计时参考。     

Scattering of surface water waves involving semi-infinite floating elastic plates on water of finite depth

Two problems of scattering of surface water waves involving a semi-infinite elastic plate and a pair of semi-infinite elastic plates,separated by a gap of finite width,floating horizontally on water of finite depth,are investigated in the present work for a two-dimensional time-harmonic case.Within the frame of linear water wave theory,the solutions of the two boundary value problems under consideration have been represented in the forms of eigenfunction expansions.Approximate values of the reflection and transmission coefficients are obtained by solving an over-determined system of linear algebraic equations in each problem.In both the problems,the method of least squares as well as the singular value decomposition have been employed and tables of numerical values of the reflection and transmission coefficients are presented for specific choices of the parameters for modelling the elastic plates.Our main aim is to check the energy balance relation in each problem which plays a very important role in the present approach of solutions of mixed boundary value problems involving Laplace equations.The main advantage of the present approach of solutions is that the results for the values of reflection and transmission coefficients obtained by using both the methods are found to satisfy the energy-balance relations associated with the respective scattering problems under consideration.The absolute values of the reflection and transmission coefficients are presented graphically against different values of the wave numbers.     

水面舰船流噪声数值预报研究与应用

在梳理流噪声数值预报方法的基础上,采用流场大涡模拟（large eddy simulation,LES）和声学边界元（boundary element method,BEM）方法在频域内计算预报了船体流噪声谱曲线,求取了其等效声中心.LES计算时选用动力学Smagorinsky-Lilly（dynamic Smagorinsky-Lilly,DSM）亚格子应力模型,流噪声由船体壁面脉动压力和法向速度特性决定,声源节点和声节点变量传递采用一对一的守恒传递方式.结果表明：某型船在航速14 kn时,裸船体流噪声在20 Hz~2 kHz频段内总声源级为133dB;当计算有效频段扩展到20 kHz时,总声源级达143.3 dB.流噪声主要来源于兴波引起的涡量,且主要集中于100 Hz~10 kHz频段.球首尾流区和船体尾涡区对流噪声辐射量贡献明显,特别是球首尾流区,对全频段都有明显的贡献,为水面舰艇流噪声研究提供了一条新的途径.     

县乡公路沥青面层平整度的控制探析

通过对公路平整度的重要性以及在沥青公路施工中造成路面不平整的原因进行分析,提出控制公路沥青面层平整度的几点措施.