自动控制、信息管理技术-铁路运输、高速公路、城市交通以及工矿企事业

地铁项目的数据通信系统 总体设计 研发 测试 实施 DCS SDH 无线通信 地铁无线覆盖 铁路通信信号应用化开发 Wireless networking in tunnelling projects Tunnelling and Underground Space Technology 隧道和地下工程空间科技学学报 Emerging collaborative technologies and working methods often require tremendous engineering and organisational efforts for successful implementation of information and communication technologies ICTs According to a research conducted in Turkish construction industry most of the problems that occur during the construction phase are due to lack of co operation and communication between designers and contractors and lack of prompt expert decisions during on site engineering Similar to any major construction project tunnelling project s success is highly dependent on collaborative team work where communication and information exchange take place between project members Distributed collaborative teamwork as the case in most of the large scale construction projects as well as tunnelling projects empowered by state of the art information and communication technology promises more efficient work processes reduced travelling needs and increased opportunities for project communication Following the fast development of mobile computing in recent years many sectors have adopted mobile devices and wireless technologies enabling real time information transfer thereby improving business processes For some years the feasibility of implementing wireless solutions to construction sites has been researched Potentially mobile and wireless technologies enable construction staff to be more flexible in terms of location and time For better use of mobile collaboration in construction projects mobile technologies and construction sector have to be examined in some detail to implant the most suitable technology for real time information access and improved collaboration of distributed teams in construction However case studies in construction are very limited in number and scope This paper discusses and proposes an implementation scenario of wireless networking in Marmaray a multi site tunnelling project in Istanbul Benefits possible problems and cost assessments are discussed Article Outline 1 Introduction 2 Tunnelling projects and the relevance of efficient communication 3 Wireless local area networks WLANs 3 1 WLAN design 3 2 WLAN security 4 Implementation Scenario Marmaray project 4 1 Project details 4 1 1 Immersed tunnel under Bosphorus 4 1 2 Underground tunnels 4 1 3 Stations 4 2 Proposed mobile collaboration in marmaray project WLAN design 4 2 1 Mobile collaboration 4 2 1 1 Advantages of using wireless communication and mobile collaboration 4 2 1 2 Execution of the works 4 2 2 Wireless local area network design and calculation of overall system cost 4 2 2 1 High gain directional antenna ANT24 1801 4 2 2 2 Wireless access point DWL 2700 AP 4 2 2 3 Estimated overall system cost for Marmaray project 5 Conclusion 6 Further research Monitoring of rail corrugation growth due to irregular wear on a railway metro curve Wear Short pitch rail corrugation developing on the low rail in sharp curves is a problem experienced by many railway networks worldwide Because of the large existence of small radius curves metro lines are particularly affected This case study is performed as part of a project which aims at developing a numerical tool for prediction of rail corrugation growth on curves The development of corrugation on a 120 m radius curve of the Stockholm metro has been monitored by repeated measurements of rail roughness and train pass by noise Within a grinding interval of 1 year severe short pitch corrugation was build up with maximum peak to peak magnitudes of about 0 15 mm Spectral analysis of measurement data shows large roughness magnitudes in the wavelength interval 4 14 cm with peaks at approximately 5 cm and 8 cm The corrugation pattern has a pure longitudinal direction with corrugation ridges transverse to the track direction and an irregularly varying magnitude along the 100 m long measured track section The roughness growth rate increased with time until 300 days after rail grinding thereafter only moderate additional roughness growth was observed Because of moderate train speeds of about 30 km h the rolling noise caused by the corrugation has a low frequency content 2003 and tak Metro or Data communication system or DCS or Wireless Communication or SDH or Metro wireless coverage or Railway and Signal or Communication and Project or Overa