地铁暗挖隧道马头门施工技术

分析常规的倒挂井壁格栅形式竖井马头门的开设步骤和措施,说明在施工过程中若遇到其他特殊情况,按常规方法开设马头门,会产生很大的安全风险甚至导致事故发生。对不同施工条件下的马头门施工进行剖析,研究在不同施工条件下的暗挖隧道马头门施工的不同方法和措施,以确保施工安全,同时可避免从地面对马头门位置的土体进行预加固而发生的大量费用,为今后类似工程施工提供经验借鉴。     

减震器支座冲压成型模拟分析

使用三维CAD软件UG对车用减震器支座进行三维建模,在基于一步成型法理论的Hyperform中建立了零件的有限元模型。模拟了结构的成型过程,分析了其可成型性,减薄率、应力和应变等,根据冲压工序模拟了没有中间冲孔的减震器支座的冲压成型,并与带中间孔的分析结果进行了对比,给出了最终的坯料形状,为Hyper-form应用于实际生产提供了参考依据。     

FOPID在船舶焊缝跟踪控制中的应用

针对船用焊接机器人焊缝跟踪问题,提出一种分数阶比例积分微分(Fractional Order Proportion Integration Differentiation,FOPID)控制技术.根据FOPID控制原理,设计FOPID控制器.针对FOPID特有的控制参数λ和μ,通过阶跃响应试验确定最佳论域范围,优化设计F...     

软弱围岩隧道短台阶法开挖数值模拟与监测分析

文章依托炎汝高速公路花子坳隧道施工实例,利用有限元模型对隧道Ⅴ级围岩深埋段短台阶法动态开挖过程的应力及位移变化情况进行了数值模拟分析。实测结果表明：短台阶法施工效果良好,围岩压力及拱顶下沉、周边收敛变形均在可控范围内。     

客运专线基床底层改良土施工工艺及单价分析

着重介绍路堤基床以下石灰改良土填料（路拌改良土）的3种施工工艺以及影响改良土质量的主要因素及其控制参数。在对照分析了3种施工工艺的差异后，结合铁道部颁布的113号文，对改良土的单价进行分析，并就影响改良土单价的主要因素（石灰费用和土方运输费用），依据盈亏平衡原则，通过经济性比较，分析出石灰价格和石灰损耗量的临界点及改良土与AB级填料的经济运距临界点，为合理选择改良土施工方法和路基填料提供有益的参考。     

混合式步进电动机的轻重步机理

分析了混合式步进电动机的单步响应特性,阐明了电机单步运行时的轻重步机理,实例分析了五相混合式步进电动机４～５相通电运行时的单步响应特性,确定了轻重步的变换过程,指出了改善电机轻重步现象的相应措施。     

车身结构件多步冲压工艺数值模拟

分析了左后悬挂架形成特点，采用两步拉延方式完成成形；然后确定首次拉延的四种方案，研究不同变形形式和变形量对后继拉延所造成的成形质量的影响；通过数值模拟结果中的FLD曲线、材料厚度分布图、最大主应变分布图和拉延成形变形裕度，研究车身结构件多步冲压工艺设计。     

公路改建时新旧路结合部施工技术

针对公路改建时新、旧路面结合部易出现病害的问题,从公路改建施工前的准备工作着手,结合具体的施工经验,分别对新、旧路的边坡结合部、路基结合部、路面结合部以及涵洞结合部的具体处置方法、注意事项进行了阐述．对以后类似公路改建工程具有一定的借鉴意义。     

Sustainability assessment of inland transportation in China: A triple bottom line-based network DEA approach

The transport sector accounts for nearly one third of the world’s total energy use, while inland transport alone is responsible for half of the global petroleum consumption. The expansion of motorization in newly industrialized economies necessitates setting realistic targets. To support decision-makers in better assessment of transport sustainability performance, we introduce a systematic triple bottom line-based approach to evaluate inland transport, considering social, economic, and environmental dimensions of sustainability. The proposed network data envelopment analysis (DEA) measure organizes the three components of the system into a parallel structure, allocates shared input across subsystems, and incorporates undesirable output. The empirical application determines the efficiency of regional inland transportation systems in China from 2006 to 2015. The results indicate a rise in overall transport efficiency between China’s 11th and 12th five-year development plan periods and link the economic growth with a decrease in environmental transport efficiency in the Central and Western zones and with a decline in social efficiency in the Eastern zone. Since 2012, the social sustainability remains the weakest component of inland transport, which requires special attention by policy-makers to support vulnerable groups of transport users. This study provides further insight into the investigated measures and proposes recommendations for the improvement of inland transport in China.     

A STEP-BY-STEP INTEGRAL METHOD FOR ACTIVELY CONTROLLED STRUCTURES

Introduction　　 Since 1 970 s,the researches in active controlofcivil engineering structures have been developedfor30 years[1] .It is now at the stage where full-scale active systems are installed in actual struc-tures and perform well for the purposes intend-ed[2 ,3 ] .Although a significant progress has beenmade,the true potential of active vibration controlremains non- exploited fully[4] .For example,manyof the current operating systems are designed pri-marily on the basis of the classical…