广州轨道交通网络化运营客流特征和问题

广州轨道交通在实现初步网络化运营后,出现暴发性客流增长的特征。阐述广州客流的成长历程和发展规律、线网客流特征和特殊性,以及目前运营存在的问题。对我国的现行设计标准与实际运营状况进行对比和研究,分析设计中存在的不足,并对设计标准及参数中的一些问题进行探讨。最后提出建议:设计不应唯预测客流而论,系统规模选择应有前瞻性,车厢内站立标准应放宽,应高度重视换乘站设计。     

长大管棚预支护在西安地铁区间隧道设计施工中的应用

管棚超前预支护作为隧道开挖的辅助方法,有效地解决了隧道在穿越浅埋大偏压、软弱破碎围岩、泥流地下水活动较强等特殊困难地段的隧道开挖问题,也有效地限制了地面沉陷.以西安地铁2号线体育场站—小寨站区间隧道设计施工为例,结合监测数据,介绍了长大管棚预支护在西安地铁设计施工中的具体应用,可供类似工程的设计施工参考.     

地铁站台屏蔽门系统的结构强度与安全性分析

根据地铁站台屏蔽门的安装限界要求,分析了站台屏蔽门系统的荷载工况.针对最恶劣荷载工况,采用通用有限元软件ANSYS,对结构的整体刚度特性和结构变形量进行了计算,对站台屏蔽门系统的结构安全性进行了分析.     

客运专线轨道结构选型分析

无砟轨道已成为我国客运专线轨道结构的基本形式,运用越来越广泛,轨道结构的选型显得尤其重要.基于沪昆客运专线,深入研究无砟轨道和有砟轨道的结构形式.首先结合地形、地质、地貌等特征,从施工性、维修性、经济性、适应性4个方面对轨道的选型展开论证,接着从经济性入手具体阐述轨道经济在轨道结构选型中的应用,最后对所选定的无砟轨道结构建立动力学模型,计算动力学指标,进一步验证所选定的无砟轨道结构的合理性.     

CBTC系统中联锁与ATP接口简析

简要分析基于通信的列车运行控制(CBTC)系统中联锁与ATP的接口功能、内容,有助于进一步理解CBTC系统。     

铁路隧道现场监控量测回归分析

介绍了包西铁路通道大保当至张桥段铁路中新九燕山隧道现场监控量测记录和数据的回归分析方法,应用铁路隧道现场监控量测结果,可以指导铁路隧道现场施工,科学合理确定开挖方法,及时施工二次衬砌,从而保证铁路隧道施工顺利进行。     

高桥墩无支架施工技术

针对特大桥高桥墩无支架施工情况,阐述了无支架施工的施工工艺技术,即利用新建桥墩作为承载主体进行搭设施工所需的工作平台,随着桥墩不断向上施工,工作平台整体向上平移,这种桥墩施工技术具有很强的可操作性和较大的经济价值。     

海船稳性调整质疑及改正意见

对《船舶货运》、《货运技术》等教科书关于“船舶稳性调整”这一内容中存在的问题作了系统分析,提出了一些不同看法及修正意见,为船舶驾驶员在调整船舶稳性时提供了正确的方法,准确的计算公式及判别式,修正了在船舶稳性调整方面长期来存在的欠缺,对保障船舶的安全航行具有积极意义。     

Analysis of Passive Limited Supporting Force of Curved Shield Tunnel Excavation FaceEI北大核心

Research purposes: In the construction process of curved shield tunnels, the force of excavation face is extremely complex and the stability is difficult to control, so it is very likely that the thrust of the jack will cause uplift of the soil in front because of passive failure. Taking the sand strata as an example, this paper established a combination model of "inverted ladder-wedge prism" to reveal that the soil in front of the excavation face of curved shield tunnels uplifts up because of passive failure based on the silo theory and limit equilibrium method, and deduced the calculation method of passive limited supporting force for curved tunnels. Then, we confirmed the accuracy and reliability of this model and calculation method through programing and simulating. Research conclusions:(1) The passive limited supporting force increases with the increase of buried depth and internal friction angle, and the growth rate gradually increases. (2) When the radius of the line is less than 200 m and the internal friction angle is more than 25 degrees, the passive limited supporting force is very sensitive to the curvature radius, and when the radius is more than 800 m, the passive limited supporting force is almost no difference with straight tunnels. (3) The numerical results indicate that the numerical solution is consistent with the theoretical solution and the difference is quite small. (4) The research results can provide theoretical basis for determining the passive limited supporting force in the constructions of similar curved shield tunnels especially small turn radius shield tunnels. © 2018, Editorial Department of Journal of Railway Engineering Society. All right reserved.     

Research on the Cause and Influential Factors of Tunnel Lining Cracking of Side Wall in Seasonally-frozen RegionsEI北大核心

Research purposes: In recent years, tunnel diseases like lining cracking and water leaking during spring thawing period, caused by frost heaving of surrounding rock, have occasionally occurred in high-latitude seasonally-frozen regions of northwest China and northeast China, which has seriously affected the tunnel structure and operation safety. Taking several railway tunnels in northwest China as an example, this paper investigates the cause and main influencing factors of longitudinal cracking of side wall in winter in seasonal frozen soil area by means of field test, laboratory experiment and numerical simulation. Research conclusions:(1) When the water content of surrounding rock of tunnel built in strongly-weathered sandstone is 12.3% and the frozen depth of surrounding rock is up to 60 cm, the maximum tensile stress of side walls is 2.28 MPa, which is larger than the ultimate tensile strength of C30 concrete, then the horizontal lining cracking will appear on side walls under the effect of continuous negative temperature in winter. If the lining bears part of the surrounding rock load, the longitudinal cracking degree of the side wall will increase. (2) Under the effect of frost heaving loads, the cracking of tunnel lining has its own characteristics of symmetry, seasonality and accumulation, etc. The cracks appear in winter and distribute in the middle of side walls. As the temperature is rising, the crack begins to shrink. (3) The frozen circle thickness and water content of surrounding rock should be used as main indicators during the process of calculation of frost heaving loads of surrounding rock in seasonally-frozen regions. (4) The research results can be used for reference in tunnel design, operation and maintenance in seasonal frozen soil area. © 2018, Editorial Department of Journal of Railway Engineering Society. All right reserved.