基于故障模式、影响及危害度分析(FMECA)的地铁车辆检修工艺优化方法

提出了一种地铁车辆检修工艺优化方法。该方法采用FMECA(故障模式、影响及危害度分析),对地铁车辆运营过程中的故障数据进行分析,并根据分析结果对当前的地铁车辆检修工艺进行优化,以提高检修作业的合理性和效率。以地铁车辆高压供电系统为例,说明了该优化方法在地铁车辆高压供电系统上的实施流程;结合相关标准的规定建立了定量化的地铁车辆设备危害性风险评价矩阵,用以确定故障模式的可接受程度;通过建立可接受程度与该检修项点检修等级的对应关系,最终得到检修工艺的优化方案。     

基坑开挖引起复合地基下卧双线地铁隧道附加荷载的计算研究

为研究基坑开挖时复合地基及竖向、横向"双洞效应"对下卧双线地铁隧道竖向、横向附加荷载的影响,基于Mindlin应力解,得到在复合地基侧摩阻力作用下隧道轴线上的竖向、横向附加荷载,通过迭代法计算得到"双洞效应"引起隧道轴线上的竖向、横向附加荷载,借助竖向、横向总附加荷载引起的隧道位移对比验证,并分析隧道位置改变对侧摩阻力和"双洞效应"引起隧道竖向、横向附加荷载的影响。研究结果表明:侧摩阻力和"双洞效应"对隧道竖向、横向附加荷载的影响是不可忽略的,其影响主要表现为减小隧道的竖向、横向总附加荷载,且影响范围不变;在施工条件和规范容许范围内,应尽量减小双线隧道之间的距离,以及增大隧道与基坑中点的距离;当需要严谨精确地计算小净距地铁隧道"双洞效应"引起的附加荷载时,必须选用迭代法计算。     

进口汽车零部件监测数据风险分析与模型建立

通过对我国近两年进口汽车零部件现状进行分析,结合汽车零部件召回相关数据,提出进口汽车零部件质量安全风险监测要点。通过层次分析法和失效模式与效应分析法两种方法建立风险评估数据模型,并对比模型结果,对各种进口汽车零部件风险预警等级进行分类,针对分类等级提出相应的风险监管建议,包括风险管理、完善信息平台和及时更新相关技术标准等,探索风险监测管理模式,建立系统的风险识别和评估的触发机制研究,提升我国进口汽车零部件的质量安全风险管理水平。     

二灰碎石组成设计与施工工艺的优化

从施工角度就改进和优化现有二灰碎石混合料级配组成设计和传统的施工工艺提出了几点建议,推荐集料级配范围和4阶段碾压模式.对二灰碎石基层施工具有积极的指导意义.     

Protective effect of polymer coating on the circular steel plate response to near-field underwater explosions

To understand the intrinsic strong interaction between the soft coating and near-field underwater explosion, a series of comparative live fire tests are implemented. Nine steel circular plates with three configurations (i.e. rubber coated plate, foam coated plate and bare plate) are tested using 1.5 g PETN detonator. The stand-off between the plate center and explosive charge is ranged from 3.41 to 1.14 times of the maximum bubble radius. The transient strain history of the plate and acceleration history of the metal base fixture are monitored. The whole explosion process including local cavitation and bubble motion is recorded by an APX-RS high speed camera. Test results show that the compressibility of coating layer is the dominative factor that controls its protective performance in the shock wave loading phase. The more compressible foam coating distinctly reduce the shock wave intensity by local cavitation before enters the densification phase, while the explosion bubble shape and even the direction of water jet can also be changed. But the attenuation performance in the bubble loading phase is not as optimistic as that in the shock wave phase because more deformation space is required while the core has often entered the densification phase.     

Bottleneck congestion and distribution of work start times: The economics of staggered work hours revisited

Since the seminal work of Henderson (Henderson, J.V., 1981. The economics of staggered work hours. Journal of Urban Economics 9 (3), 349–364), a number of studies have examined the effect of staggered work hours by analyzing models of work start time choice that consider the trade-off between negative congestion externalities and positive production externalities. However, these studies employed flow congestion models to describe traffic congestion. This study develops a model of work start time choice with bottleneck congestion and discloses the intrinsic properties of the model. To this end, this study extends Henderson’s model to incorporate bottleneck congestion. By utilizing the properties of a potential game, we characterize equilibrium and optimal distributions of work start times. We also show that Pigouvian tax/subsidy policies generally yield multiple equilibria and that the first-best optimum must be a stable equilibrium under Pigouvian policies, whereas the second-best optimum in which policymakers cannot eliminate queuing congestion can be unstable.     

水泥粉煤灰碎石基层材料路用性能的研究

对水泥粉煤灰碎石基层材料的各项路用性能进行了试验研究.研究表明,水泥粉煤灰稳定碎石兼具水泥和二灰稳定材料的优点,将其作为路面基层材料是可行的.     

二灰冷再生沥青路面基层路用性能研究

通过对原路材料进行材料组成分析,并且通过对几种不同配合比的冷再生材料的无侧限抗压强度、劈裂强度、冲刷性能的初步研究,对二灰冷再生材料的性能做出了初步评价.二灰冷再生材料基本可以满足规范对沥青路面的半刚性基层的要求.     

预应力锚索抗滑桩结构在处治滑坡中的应用

文章结合鹰阳关-莲塘二级公路K54+800处滑坡采用预应力锚索结构施工实践,介绍了预应力锚索抗滑桩结构在滑坡处治中的注意事项及使用效果.