The Members of Underground Works Chambers have come together to provide expert services and support to assist in bringing tunnelling and underground works to successful completion and operation.
Between them, they bring to the table individual and collective expertise in the following critical areas: Design & Construction; Ground Conditions; Contracts; Insurance; Dispute Avoidance; Mediation; Dispute Resolution by Arbitration; Investigations; and Operations.
Design & Construction
At the heart of the design process for tunnelling and underground works is the consideration of risk. The design process involves many aspects, including full appraisal of the requirements of the project to meet the objectives of the Owner, comprehensive investigation of the ground conditions, selection of tunnel alignment (both vertical and horizontal), consideration of likely construction methods and their associated risks, design of the tunnel support system, and estimation of the probable ground movements caused by the construction and their potential effects on overlying and adjacent infrastructure.
Many factors influence successful construction of tunnels and underground works. These include full consideration of suitable construction options and the attendant risks, understanding of the nature of the ground, satisfactory procurement and contractual arrangements, and effective project management.
In reality for tunnelling and underground works there is no real distinction between design and construction: successful execution of a project requires full understanding and engagement by all parties of the overall strategy, from the first consideration of a tunnelling solution right through to the operation of the completed project.
Tunnelling and underground works are characterized by an extreme dependence on the ground. Both design and construction are dominated by the ground. It is essential to predict its properties, variability, and behaviour when excavated, with as much certainty as practicable. Groundwater conditions are a vital part of the ground characterization.
Every project requires satisfactory acquisition and interpretation of data relating to the ground and to the prediction of its behaviour during tunnelling. The nature of the ground in relation to possible methods of construction needs to be reliably established during the investigation stages.
Ground investigation is principally part of the design process and is usually undertaken in stages: the first stage being a desk study of the site history and existing geotechnical information, including a geological appraisal; this is followed by fieldwork comprising boreholes, geophysical and insitu testing, sampling and laboratory tests. A third stage is undertaken as part of the construction project itself once the full details of the construction are known; there may well be continuous investigation of the ground ahead of an advancing tunnel.
It is essential that the ground investigations and their proper interpretation are sufficiently comprehensive to characterize the ground conditions with reasonable accuracy – in order to minimize the risk of unforeseen problems during construction.
The agreements between parties for all aspects of underground works are greatly influenced by the agreements they reach in writing. The range of agreements is extremely broad internationally offering participants a broad range of reward, risk and dispute resolution options.
From bespoke agreements to the latest FIDIC Emerald Book timely and informed contractual advice and support forms a fundamental risk management function for projects and operations.
Prudent management of risk always includes insurance. This ranges from 100% self insurance to having insurers participate as a partner in a project. Decisions about project procured insurance through the spectrum of distributed insurances along with agreement as to the exact terms of the insurance, require detailed understanding of insurance law and the technical nuances of events triggering actual or anticipated claims.
Given the complexity of tunnelling works and the risks involved, it is inevitable that issues will arise in the course of a project which will require resolution. Unless attended to immediately as the works progress and with application of appropriate expertise, delay, additional cost and damage to workforce collaboration is likely to follow.
The rapid uptake of the dispute resolution board process (DRBs) worldwide in the construction industry has avoided numerous disputes and delivered significant cost savings. The process is designed to work to resolve issues before they become formal disputes requiring mediation or arbitration. It can result in the generation of far fewer unresolved claims at project completion.
DRBs are now common in substantial infrastructure works such as tunnelling projects around the world. The World Bank supports the use of DRBs in the civil works it finances.
It is well recognised that in construction contracts, in the event of an issue persisting which is not avoided by the DRB process, a formal mediation may be required. Mediation is recognised as a cost effective and timely way to manage disputes, before they need to be resolved by arbitration.
Dispute Resolution by Arbitration
Arbitration is a process in which the parties to a dispute present arguments and evidence to an appointed arbitrator or panel of arbitrators (usually three). This constitutes the arbitral tribunal which makes a binding determination. The process is private and, subject to the parties’ agreement, can be confidential.
Properly managed, arbitration offers a flexible and efficient means of resolving disputes both domestically and internationally. The decision of the arbitral tribunal is given as an award which is enforceable in domestic superior courts worldwide.
It is common practice for investigations to be undertaken when undesirable events occur that are significant and unexpected.
Typically, such investigations are highly sensitive, confidential and time critical. Investigations may be initiated external to a project or by one or more parties within a project. They are almost always confidential, and findings usually have both financial and reputational consequences, often with potential implications for civil and criminal liability at personal and corporate levels.
Maintaining operational performance of underground infrastructure over long periods of time demands sensitivity to changes in the condition of built infrastructure, nature of the use and acceptability of risk.
With operations often anticipated to extend beyond 100 years decisions about refurbishment, operations and control often demand subtle analysis of competing information to ensure safe optimal use of the asset over multiple human generations. From condition reports and use projections, to the lessons learned from catastrophic events, the demands of operations define the social utility of the asset.