注浆技术在处理桥头搭板底脱空问题上的应用

桥头搭板底脱空的病害会加剧搭板的损坏,采用注浆技术,填实搭板底的脱空处,会延长搭板的使用寿命及消除不利于行车的安全隐患。     

钟形减振穴的设计研究

对双桨平底船的尾部振动,根据实船螺旋桨脉动压力测试结果,以及金属橡胶板的模型试验与模态分析,设计了钟形减振穴,以减小螺旋桨激起的船舶尾部振动,并在国内的双桨平底船上首次应用获得成功。 文中提出了适用于双桨平底船的螺旋桨脉动压力估算的经验公式,其计算值与实测值相当接近,可供船舶初始设计阶段应用。     

900t下导梁高速铁路架桥机有限元分析

应用有限元分析程序Super SAP对900t下导梁高速铁路架桥机进行有限元分析,重点描述了怎样用梁单元模拟总体结构,并介绍了主要部件的屈曲稳定性分析。     

内河测量船水文绞关触底感应装置的设计与应用

水文绞关在长江水文测量中发挥着重要作用,但实际测量工作中,绞关钢缆故障时有发生,既影响测绘工作进度,又增加员工劳动强度。本文通过设计一款绞关自动触底感应装置,让绞关滚轮上弹簧装置感应钢丝受力情况,并利用行程开关自动控制绞车运转。经验证,该装置能有效减少绞关发生缠绕、脱盘的故障率,在不同水深、流场条件下,性能达到设计要求,装置感应灵敏,安装简单,具有内河测量船舶应用条件。     

管道水平定向钻穿越长江的技术分析

介绍了宁波-上海-南京进口原油管道定向穿越长江施工的设备配置以及管道水平钻进的入土角、出土角、曲率半径和穿越深度等设计要素的确定方法,分析了管道强度和回拖力的计算方法,详细阐述了施工过程。     

基于听觉感知特征的水下目标回波分类(英文)

In underwater target detection, the bottom reverberation has some of the same properties as the target echo, which has a great impact on the performance. It is essential to study the difference between target echo and reverberation. In this paper based on the unique advantage of human listening ability on objects distinction, the Gammatone filter is taken as the auditory model. In addition, time-frequency perception features and auditory spectra features are extracted for active sonar target echo and bottom reverberation separation. The features of the experimental data have good concentration characteristics in the same class and have a large amount of differences between different classes, which shows that this method can effectively distinguish between the target echo and reverberation.     

Damping of Oblique Ocean Waves by a Vertical Porous Structure Placed on a Multi-step Bottom

Oblique ocean wave damping by a vertical porous structure placed on a multi-step bottom topography is studied with the help of linear water wave theory. Some portion of the oblique wave, incident on the porous structure, gets reflected by the multi-step bottom and the porous structure, and the rest propagates into the water medium following the porous structure. Two cases are considered： first a solid vertical wall placed at a finite distance from the porous structure in the water medium following the porous structure and then a special case of an unbounded water medium following the porous structure. In both cases, boundary value problems are set up in three different media, the first medium being water, the second medium being the porous structure consisting ofp vertical regions-one above each step and the third medium being water again. By using the matching conditions along the virtualvertical boundaries, a system of linear equations is deduced. The behavior of the reflection coefficient and the dimensionless amplitude of the transmitted progressive wave due to different relevant parameters are studied. Energy loss due to the propagation of oblique water wave through the porous structure is also carried out. The effects of various parameters, such as number of evanescent modes, porosity, friction factor, structure width, number of steps and angle of incidence, on the reflection coefficient and the dimensionless amplitude of the transmitted wave are studied graphically for both cases. Number of evanescent modes merely affects the scattering phenomenon. But higher values of porosity show relatively lower reflection than that for lower porosity. Oscillation in the reflection coefficient is observed for lower values of friction factor but it disappears with an increase in the value of friction factor. Amplitude of the transmitted progressive wave is independent of the porosity of the structure. But lower value of friction factor causes higher transmission. The investigation is then carried out for the second ca     

综合稳定低液限粉土在路面底基层中应用

使用塑性指数小于12的低液限粉土作为高等级公路底基层材料,通过实验选用石灰、粉煤灰、水泥综合稳定土,工程造价低,且强度能满足要求。该方法对于无更好土源情况的苏北地区有较大帮助,为修建高等级公路底基层提供较好方法。     

长寿命路面沥青层底拉应变影响因素分析

沥青层底拉应变是长寿命沥青路面在设计中的一个重要指标,可以作为路面是否能够达到长寿命要求的一个初步评价标准。因此,分析影响路面沥青层拉应变的相关因素,以及各因素的影响水平对指导长寿命沥青路面结构材料的设计具有十分重要的意义。     

高压旋喷注浆法在钻孔灌注嵌岩桩底持力层补强加固中的应用

文中以清远北江大桥扩建工程1#墩1#桩桩底持力层强度不足为案例,从高压旋喷注浆的原理、实施步骤等方面阐述解决钻孔灌注嵌岩桩底持力层承载力不足的补强加固方法。实践证明：高压旋喷注浆补强加固方法简单可行,安全可靠。