Assessing governance issues of urban utility tunnels

Abstract

Throughout the centuries, utilities have been an important and sometimes decisive instrument in human development. Municipal policy-makers and engineers have been playing a key role in improving management and technology of urban utilities. With the growth of urban areas and the corresponding increased demand for utility services, available underground space will continue to diminish. Therefore, planning for an urban subsurface sustainable future consists of the ability to lessen the use of traditional trenching techniques and developing coordinated installations of utilities. As an innovative problem-solving technique, utility tunnels become inevitable to reduce congestion of the shallow underground. Utilities management becomes more complex as many public authorities and private companies are involved. Because of the complexity of ownership of the various utility tunnel potential occupants, some form of governmental ownership would probably be the most practicable, although other forms (individual private, joint private, or condominium) of ownership must be analysed. Whatever the form of financing and ownership, some single entity must be made responsible not only for initial construction but also for security, access control, and operation and maintenance throughout the life of the project. The purpose of this paper is to point out some of the utility tunnels innovation and organizational advantages to encourage municipal engineers to demand sustainable solutions for services congestion. Proper adequate governance and security management should be key elements of every decision undertaken in utility tunnels.

Quantitative risk assessment of a natural gas pipeline in an underground utility tunnel

“…This situation occurs when the coating has been used for many years and has not been timely replaced. Third-party interference 1.61E-02 X 4 Industrial activity 8.10E-03 X 5 High water content 8.09E-03 X 6 Inhibitor failure 3.50E-03 X 7 Poor coating quality 1.67E-03 X 8 Incorrect material selection 1.53E-04 X 9 Aging 3.10E-02 X 10 H 2 S content overproof 6.24E-04 X 11 SO 2 content overproof 8.66E-03 X 12 Other acid media 1.04E-04 X 13 Incorrect pipe material selection 16 Weld flaw 3.64E-02 X 17 Mechanical damage 1.50E-02 X 18 Misoperation of supporting structure construction 1.80E-03 X 19 Incorrect maintenance 8.47E-03 X 20 Unreasonable operation 2.20E-03 To represent the consequences of a gas pipeline accident in a utility tunnel, eight intermediate nodes were implemented: one node of "Near Miss", "Poisoning", and "Catastrophic Damage"; two nodes of "Minor Damage"; and three nodes of "Significant Damage". The levels of accident consequences of the nodes with the same names are equal.…”

“…Based on POF estimates, hazard zones can be estimated. Additionally, for directly buried pipelines, various studies have focused identifying critical threats and consequence analyses based on, for example, fault tree (FT), event tree (ET), bow-tie (BT) diagram, and Bayesian network (BN) methods [8][9][10][11][12][13][14][15]. However, few studies have analyzed gas pipeline accidents in utility tunnels.…”

“…However, few studies have analyzed gas pipeline accidents in utility tunnels. A few attempts have studied the impacts of crustal movement (e.g., earthquakes) on utility tunnel structures [16,17], analyzed fire smoke temperature distributions in a utility tunnel under different fire conditions [18,19], and identified preliminary critical threats of utility tunnel structures (but for utility tunnel accidents) [4,8,20]. At present, research work on comprehensive risk analyses of gas pipeline accidents in a utility tunnel (i.e., critical hazards identification, assessment of safety measures, and consequence analysis) is scarce.…”

Selecting utilities placement techniques in urban underground engineering

“…It is not possible to make a general statement as to the engineering-financial feasibility of utility tunnels because each situation will be different in terms of location, urban population and traffic density, utility systems to be installed, type and number of customers, costs of construction and many other factors [43]. In addition, a critical requirement in the development of urban utility tunnel systems is the cooperation and coordination of all government and utility agencies so that a workable plan can be developed [44,45]. Problems relating to the liability and security of a variety of utility systems in close proximity inside a tunnel need to be evaluated for each case by the expert panel [46][47][48][49][50][51].…”

Implementing Sustainability Criteria for Selecting a Roof Assembly Typology in Medium Span Buildings

“…Therefore, the reduction of energy consumption in the buildings sector constitutes a key measure needed to improve the efficient energy use, greenhouse gas emissions, and will contribute towards fulfillment of the Kyoto Protocol [2]. For this reason, there is an increasing interest in studying sustainability [3][4][5] in the field of building design, mainly in residential and office buildings [6]. In this sector, the facade assembly chosen is the major design factor.…”