基于远、近期合建的折多山公路隧道总体设计方案研究

为解决特长公路隧道升级改造困难问题,以折多山公路隧道项目为依托,创新性地提出远、近期合建的总体设计方案。通过交通量预测、工程造价、运营通风及逃生救援等方面综合比较,得出可实施的合建方案： 先期建设二级公路隧道主洞,设2段非贯通平导,后期直接将二级公路隧道作为高速公路隧道右洞,并贯通二级公路隧道平导作为高速公路隧道左洞。合建方案能有效节约工程造价,降低社会耗能。     

Incorporating the extended theory of planned behavior in a school travel mode choice model: a case study of Shaoxing,China

Travel to and from school can have social, economic, and environmental implications for students and their parents. Therefore, understanding school travel mode choice behavior is essential to find policy-oriented approaches to optimizing school travel mode share. Recent research suggests that psychological factors of parents play a significant role in school travel mode choice behavior and the Multiple Indicators and Multiple Causes (MIMIC) model has been used to test the effect of psychological constructs on mode choice behavior. However, little research has used a systematic framework of behavioral theory to organize these psychological factors and investigate their internal relationships. This paper proposes an extended theory of planned behavior (ETPB) to delve into the psychological factors caused by the effects of adults’ cognition and behavioral habits and explores the factors’ relationship paradigm. A theoretical framework of travel mode choice behavior for students in China is constructed. We established the MIMIC model that accommodates latent variables from ETPB. We found that not all the psychological latent variables have significant effects on school travel mode choice behavior, but habit can play an essential role. The results provide theoretical support for demand policies for school travel.     

Analysis on the Effects of Overloading on the Mechanical Properties of Tunnel Structures in the Silty Ground --A Case Study of Sutong River-crossing GIL Utility Tunnel北大核心CSCD

Based on the Sutong GIL utility tunnel project, which is constructed by the shield machine under the river, and as for the overloading problem at the river bank slope during operating period, the refined threedimensional finite element model was established to study the deformation and cracking characteristics of the tunnel segment structure under different forms of overloading. The evolution laws of section convergence, joint opening and structural stress were analyzed, and the structure damage mechanisms were revealed under conditions of large area loading and local loading. The surface-surcharge control standard was proposed. For the big diameter shield tunneling crossing the silty clay, the research results show that: (1) the deformation failure process is divided into three stages under large area loading condition, taking the design load and compressive yield of rebars inside haunch as the critical points respectively. The first stage is characterized by the elastic stress, the second stage is in plastic state with fracture, and the third stage is accelerating deformation and instability stage. The vertical convergence is 110.5 mm with no opening of joints when rebars are yielded; (2)the deformation failure process under local loading condition is also divided into elasticity, plasticity and instability stages, taking the design load and tensile yield of rebars outside haunch as the critical points respectively. The vertical convergence is 152.6 mm with joint opening of 4.36 mm; (3) the early-warning values of additional stress on the ground under conditions of large area loading and local loading are 110 kPa and 70 kPa respectively. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

兰郑长成品油管道减少混油的方法

针对兰郑长成品油管道在顺序输送过程产生大量混油的问题,文中从初始混油、沿程混油、黏度、停输界面、不满流等方面分析混油形成原因,并结合兰郑长成品油管道实际运行情况,从4个方面进行具体分析,最后提出减少停输时间、增大输量、合理安排顺序输送次序、切外输前避免切罐操作等解决措施。     

东海涌浪环境下大型起重船吊装组块耦合运动响应数值模拟研究

我国东海海洋环境复杂,经常出现小波高、长周期的涌浪.长周期涌对系泊大型起重船吊装海洋平台上部组块影响比较大,尽管涌的波高较小,但是,吊物组块运动幅度明显比同等波高海况时的要大,严重影响了海洋平台的安装施工效率和进度,甚至威胁作业安全.本文采用水动力势流软件,建立系泊-大型起重船(包括吊臂)-索具-大型组块吊物的耦合运动模型,研究复杂涌浪环境下耦合系统运动响应特性及其机理,并开展了参数敏感性分析,讨论对耦合响应影响因素.最后,对东海涌浪情况下起重安装施工,提出了降低吊装组块运动响应的建议措施.     

Buck斩波电路电流连续与电流断续的比较研究

对降压斩波电路负载加反电动势其电流在不同情况下发生的连续和断续现象进行了研究。根据分段线性化思想,推断出降压斩波电路输出电流在断续情况下的条件,给出了其在电流断续的计算公式,为其实际应用提供了方便。     

内支线集装箱船舶非标舷梯的研制及改造应用

内支线集装箱船舶,在靠泊码头时,通常采用跳板或竹梯上下船的方式,虽然提高了船舶装载率,初投资较少,但对船员上下船而言,存在较大风险,不利于港口的安全建设与管理。以洋山港码头为例,通过分析内支线船舶的结构并结合码头实际装载状况,研发的一款适合于内支线集装箱船舶改造的非标舷梯,提高了旧船停港作业时的安全性。此产品的研发和应用可为旧船安全改造提供思路。     

辽宁省东部山区公路边沟设计降雨重现期的确定

本文分析了现行公路排水规范在设计降雨重现期方面规定的不足之处,结合辽宁省东部山区的实际降雨资料,经过计算和分析,得出了符合辽宁省东部山区公路自身特点的设计降雨重现期.     

反舰导弹末制导参数对箔条冲淡干扰效果影响分析

箔条冲淡干扰是水面舰艇对抗雷达末制导反舰导弹的重要手段之一,冲淡干扰效果受多方面因素的制约.分析了方位搜索角和距离搜索波门等末制导雷达参数对箔条冲淡干扰效果可能造成的影响,通过计算机仿真进行了验证,并提出了消除影响的初步思路.     

大型绞吸式挖泥船台车系统的设计研究

介绍了大型绞吸式挖泥船的台车定位装置的系统原理及组成,并对台车设计中一些关键数据的选择进行了仿真研究,对台车的结构强度进行了有限元分析计算.