Tunnel vision? Brunel's Thames Tunnel and project narratives

Looking at historical projects has much to offer our understanding of project management, for both research and practice. However, there are important challenges in how alternative narratives about such projects are reconstructed and related to each other. To explore these challenges, this paper uses the example of the Thames Tunnel project, completed under the direction of Marc Brunel in 1843, and reputed to be the first tunnel to be built under a major river. In telling the story of the project, we focus on five alternative discourses: technico-rational; practice; networks of people, things, and ideas; politics; and society. The common response to such variety is either to attempt to construct an overarching meta-narrative, or to explore the differences as a way of highlighting the localized and contingent nature of knowledge about projects, or adopt some intermediate position somewhere on the spectrum between these two extremes. Instead we seek a different route grounded in a sociology of knowledge that acknowledges simultaneous, provisional, and contested processes of division and stabilization in the ways that epistemic communities constitute knowledge through their own narratives and practices. These have implications for the stories that are told about project management and, crucially, the activities and interests that both shape and are shaped by such narratives.     

深排隧道钢纤维补强衬砌混凝土-伦敦Lee Tunnel

钢纤维补强能够极大提升混凝土结构物的耐久性能,非常适用于长寿命,高耐久性,并且供用环境腐蚀条件苛刻,磨耗严重的都市深层排水隧道衬砌混凝土。依据有关钢纤维补强混凝土结构的国际混凝土结构联合会制订的模型代码：fib model code 2010,以及欧洲的相关技术规范,结合伦敦的深层排水隧道：Lee Tunnel的具体工程实例,对如何应用钢纤维补强技术在盾构隧道衬砌混凝土管片,以及现场浇筑二次衬砌自密实混凝土进行了探讨。同时通过钢纤维补强混凝土缺口梁试件的抗折强度试验,大型梁试件的弯曲加载试验,以及试验结果的非线性有限元逆向解析,确认了钢纤维取代钢筋的结构补强性能,控制裂缝效果,以及应变硬化性能,能够满足Lee tunnel工程项目的砌筑混凝土性能要求,适用于深层排水隧道:Lee tunnel衬砌混凝土补强。     

Natural Ventilation by Air Captors and Extractors Sheds in Hospitals in Brazil： Wind Tunnel Measurements

Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures consist of roof openings that work as air captors or extractors depending on their location in relation to the prevailing wind directions. The hospitals of the Sarah Network, designed by the Brazilian architect Joao Filgueiras Lima, Lele, are worldwide known for using these elements to improve natural ventilation. This paper analyses the natural ventilation performance of sheds for air collecting and extracting in two Sarah hospitals located in the cities of Salvador and Rio de Janeiro. In each building, the sheds were analyzed for air extracting and collecting. The analyses were carried out by reduced physical models in an atmospheric boundary layer wind tunnel. The wind velocity was measured at external and internal points of the buildings, using hot-wire anemometers. The results show that the wards in Rio de Janeiro hospital are 17% more ventilated than the ones in the Salvador hospital. However, this difference occurs not only because of the collecting sheds but also because of set of openings and the configuration of the covering in hospitals in Rio de Janeiro.     

Seismic Design of ＂Qaf Murrizi＂ Tunnel： The Design of Tunnels in Heterogeneous Areas

Recently based in the performance of tunnels under seismic movements a good progress is made in the seismic design of tunnels. The majority of problems in the tunnel structures take place in near fault conditions and in the case of great variation of rock properties. Not having a previous experience in the seismic design of the tunnels that pass through tectonic zones with very large heterogeneity （strong rock-soil or very poor rock that behaves like soil） this article presents the general aspects of seismic calculation of tunnels and application in a specific example. The article presents the methods of seismic input modeling, design and particularities of numerical calculations. The geological conditions in which the case study tunnel will be constructed are very common in Albanian territory and represent one of the most difficult cases for the construction of road tunnels. The applied approach for using the longitudinal models for generating time histories of acceleration that can be used as input for transversal models is very simple and will help the designers for the seismic analysis of other tunnels that will be constructed in Albania.     

Investigation on the Performance of Fire Detection Systems for Tunnel Applications––Part 2: Full-Scale Experiments Under Longitudinal Airflow Conditions

A two-year international road tunnel fire detection research project (Phase II) was completed recently. As part of this project, a series of fire tests were conducted in a laboratory tunnel facility under minimum and longitudinal airflow conditions. In addition, fire tests were also conducted in the Carré-Viger tunnel in Montreal. This paper presents the results of the full-scale experiments conducted in the laboratory tunnel under minimum airflow conditions. The performance of nine fire detection systems representing five types of fire detection technologies was investigated using representative tunnel fire scenarios. Test results showed that the response of fire detection systems to a tunnel fire was dependent on the size, location and growth rate of the fire, the type of fuel as well as the method of detection.     

Subsurface exploration and transient pressure testing from a deep tunnel in fractured and karstified limestones (Lötschberg Base Tunnel,Switzerland)

This paper summarizes the results from a subsurface exploration campaign carried out in fractured and karstified limestones and marls of the Lötschberg Base Tunnel in the Swiss Alps. The exploration program in the 3.2 km long Doldenhorn Section consisted of 50 cored and 13 destructive horizontal predrillings of 250–300 m length each (in total 14,853 m of predrillings). These boreholes were used to locate possible tunnel inflows and characterize their hydraulic properties. A new efficient hydrogeological test protocol has been developed and was systematically and successfully applied. The test protocol consists of short constant rate outflow and recovery tests in open boreholes. The on-site test analysis allowed reliable predictions of the hydrogeological conditions ahead of the advancing tunnel face in brief period of time, leading to decisions regarding further reconnaissance drillings, tunnel driving or sealing measures. Detailed analysis of the transient pressure responses of the hydrogeological tests carried out after tunnel completion led to important new findings regarding flow model identification (type and orientation of conductive fractures), aquifer parameters and boundary effects. Even though the hydrogeological tests had to be carried out within a short time frame (a few hours) they allowed characterization of large scale aquifer properties relevant for long term tunnel inflow behavior.