铁路项目材料运杂费计算问题的探讨

通过对铁路项目材料运杂费计算的论述,分析说明存在的实际问题。结合工作实践,针对材料运距计算模型、过程及参数确定等问题进行探讨分析,提出利用＂二次平均法＂计算材料平均运距具有相对优势,可以进一步推广应用。     

水底隧道复合式衬砌水压力影响因素分析

富水量较大的水底隧道,隧道防排水系统对于控制隧道涌水量和衬砌外水压力十分重要。采用数值计算方法,研究固定水头下水底隧道不同注浆参数、衬砌渗透系数及隧道控制排水量对衬砌水荷载的影响,并与轴对称解析解结果进行对比验证。研究结论:(1)渗透系数增加和注浆圈厚度减小都致使衬砌外水压力的增加;(2)初衬渗透性的变化对初衬外水压力的影响十分显著;(3)数值解与解析解的结果相差不大,非圆形隧道截面可利用等效半径求解衬砌外水压力和隧道涌水量的解析解,并用于隧道防排水的初步设计;(4)隧道注浆圈参数和初衬渗透系数一定时,增大控制排水量有利于减小二衬背后外水压力。     

升浆混凝土施工技术在港工建筑物加固工程中的应用

升浆混凝土施工技术对专项加固港工建筑物水下部分有很好的适应性和独特的优势。结合港工上已采用的典型加固案例,阐述了该方法在加固破损的沉箱码头结构、增强重力式码头抛石基床稳定性和减小已有建筑物的沉降量方面的较大优势,对升浆混凝土的施工工法程序、特点和施工的技术要点进行了叙述和分析,是一种很好的就地加固方法,尤其适用于加固一些港工建筑物破损的水下部位或基础部分。采用升浆混凝土施工技术具有经济、方便、快速和安全的特点。     

Expert S-surface control for autonomous underwater vehicles

S-surface control has proven to be an effective means for motion control of underwater autonomous vehicles （AUV）. However there are still problems maintaining steady precision of course due to the constant need to adjust parameters, especially where there are disturbing currents. Thus an intelligent integral was introduced to improve precision. An expert S-surface control was developed to tune the parameters on-line, based on the expert system, it provides S-surface control according to practical experience and control knowledge. To prevent control output over-compensation, a fuzzy neural network was included to adjust the production rules to the knowledge base. Experiments were conducted on an AUV simulation platform, and the results show that the expert S-surface controller performs better than an S-surface controller in environments with currents, producing good steady precision of course in a robust way.     

近水面水下爆炸作用下舰船损伤数值模拟

探讨使用MSC/DYTRAN模拟水下爆炸冲击波,与经验公式进行比较,认为使用该方法模拟近水面水下爆炸冲击波是合理的,使用该方法模拟舰船舭部舱段近水面水下爆炸,拟合了变形和装药沉没深度曲线,变形和爆距曲线,与试验结果基本吻合.     

Applying a semantic information Petri Net modeling method to AUV systems design

This paper informally introduces colored object-oriented Petri Nets(COOPN) with the application of the AUV system. According to the characteristic of the AUV system's running environment,the object-oriented method is used in this paper not only to dispart system modules but also construct the refined running model of AUV system,then the colored Petri Net method is used to establish hierarchically detailed model in order to get the performance analyzing information of the system. After analyzing the model implementation,the errors of architecture designing and function realization can be found. If the errors can be modified on time,the experiment time in the pool can be reduced and the cost can be saved.     

积分变结构控制原理在AUV航向控制中的应用仿真

文章研究了积分变结构控制在自主水下机器人(AUV)航向控制系统中的应用,建立了AUV水平面的非线性模型,并在特定的工作点对模型进行了线性化处理,得到了AUV的控制设计线性模型.根据变结构控制理论设计了积分变结构控制器,并给出了消除抖振的方法.仿真试验验证了该设计方法的有效性.     

深水疏浚工程船水下泵吊放装置开发设计

深水疏浚工程船水下泵吊放装置的成功开发设计为我国首制大型深水疏浚工程船疏浚装备国产化作出了重要贡献.该文对水下泵吊放装置的机构原理及设计要点作概要介绍.     

水中桩基础病害检查方法

桩基础作为桥梁结构主要承重构件直接承担桥梁上部结构传递的荷载,水中桩基础属于隐蔽工程,传统桩基检测方法无法实现桩身钢筋笼以外混凝土质量检查。由潜水员携带水下高清摄像机,对水中桩基础进行外观检查,可以直观、清晰的对桩身外表面的冲刷、混凝土剥落及植物生长等情况进行检测,能够为基础加固提供可靠的依据。     

Formation control of underwater mobile sensing networks

Formation control is essential for an underwater mobile sensing network (UMSN), and an ad hoc network which wirelessly connects underwater vehicles of sensing and/or observing types via acoustic communications, to fulfill mobile sensing tasks. The problem of formation control for a UMSN with varying topology is studied in this paper. The methodology of synthesizing distributed formation controller which stabilizes a UMSN with varying topology is proposed on the basis of the stability analysis of linear time-varying systems.