矿山用主通风机在矿山设计、建设、开采等各个阶段都承担着非常重要的角色,如何确保矿井安装使用的主通风机在可靠性、安全性、经济性方面都符合矿井当前及以后一定时期内的使用要求,是每个矿山企业都需要定期认真研讨的工作.就以上问题,本文重点阐述了当下矿山企业在用主通风机在各个阶段中,机电状态参数测定方法、参数判定规则、性能研究与诊断的方法.

针对复杂地质条件下高铁施工便道的选线问题,基于绿色建造视角,引入广义距离变换算法,将空间距离拓展为包含便道线路方案长度、各类工程量和土地占用影响等多目标的广义距离,构建便道线路优化模型,应用距离变换算法,采用双向扫描策略进行施工便道线位搜索,基于弦切支距法和方向加速法优化获得最终线路方案.通过实际案例分析,验证了方法的有效性,为类似施工便道的选线和优化提供理论与方法参考.

针对复杂地质条件下高铁施工便道的选线问题,基于绿色建造视角,引入广义距离变换算法,将空间距离拓展为包含便道线路方案长度、各类工程量和土地占用影响等多目标的广义距离,构建便道线路优化模型,应用距离变换算法,采用双向扫描策略进行施工便道线位搜索,基于弦切支距法和方向加速法优化获得最终线路方案。通过实际案例分析,验证了方法的有效性,为类似施工便道的选线和优化提供理论与方法参考。

作为人类大规模的周期性迁徙活动之一,春运承载着人们一年的辛劳、归乡的期盼和旅途的艰辛.2018年2月1日,一年一度的春运在拥挤的人潮中拉开帷幕,中国青年志愿者服务春运"暖冬行动"同步启动,首日统一行动在昆明站举行.为服务2018年春运,全国铁路系统各级团组织严格执行《铁路志愿服务管理暂行办法》,招募志愿者2万余人,系统培训、规范上岗,在全国400余个车站的2400多个志愿服务岗点,以旅客取票、进站、候车、检票、上车、乘车、出站、换乘等环节为重点,做好信息咨询、客流引导、设备协助、重点旅客服务、乘降秩序维护等服务.

Based on the summary of the limits stipulated by relevant national standards,the vehicle-track spatial coupled dynamics model was established in this paper to study the safety and stability of low vibration track (LVT)in different line conditions and different train operating conditions.The results show that,under differ-ent operating conditions (the maximum speed of passenger train is 200 km/h,the maximum axle load of freight trains is 27 t),the safety index and the dynamic gauge change of the track are within the limits specified by the standards.For passenger train,the maximum lateral stability index is 1.85,and the maximum vertical stability index is 1.88.For the freight train,the maximum lateral stability index is 2.23,and the maximum vertical sta-bility index is 3.42.The stability indicators of passenger and freight trains meet the standard of Class 1,show-ing guaranteed stability.Based on the analytical results,the LVT structure can be applied to the operation con-ditions of different kinds of passenger and freight shared railways.

Research purposes:The selection of seismic design method for intercity railway bridges under frequent and rare earthquake,has a significant influence on safety of bridge structure.In order to study the characteristics of different seismic calculation methods for intercity railway continuous girder bridges,and determine the method used in different calculation phases,taking a Jinzhou-Puwan intercity railway continuous bridge of Dalian as the engineering background,this paper firstly introduces the calculation process of railway code simplified method,response spectrum method,elastic and elastic-plastic time-history analysis method.Furtherly,the seismic analysis of intercity railway continuous bridge under frequent and rare earthquake by using three analysis method has been conducted.Finally,the results of the top displacement,the bending moment and the shear force of piers are compared.Research conclusions:(1)For continuous bridge,when it comes to longitudinal seismic effect under frequent earthquake excitation,there is little difference among railway code simplified method,response spectrum method and elastic time-history analysis.(2) When considering the horizontal earthquakeseismic effect under frequent earthquake,response spectrum method and elastic time-history analysis are preferred,using railway code simplified method to be dangerous.(3) Faced with rare earthquake,elastic-plastic time-history analysis method is more reasonable and economical.(4) Faced with rare earthquake,using railway code simplified method or response spectrum method results distortion,will seriously enlarge the pier bottom bending moment and increase the amount of reinforcement.(5) The research results of this paper have some guidance and reference for the seismic design of continuous girder bridges.

Based on the analytical solution of Mindlin theory for the additive stress calculation induced by point loading,relationship between pile radius and the Mindlin additive stress coefficient was discussed in details with different poisson ratio and the pile length.Subsequently,the minimum influence range of pile radius under differ-ent error standard was determined,and the fitting equation of influence range was also obtained accordingly.Re-search results in this study indicated that,influences of soil poisson ratio to the additive stress was at a very low level,and the greatest error was only about 5%if applied the poisson ratio value with 0.35 in common.During the calculation of Mindlin additive stress coefficient,the minimum influence range of pile radius was mainly de-termined by pile radius,and it would keep increasing with pile length.Moreover,if the error standard were 1%and 5%respectively,it would be not necessary to consider the pile radius influences as the distance to the load center had exceed 1 3.6 r0 and 6.41 r0.