Risk Management on Tunnelling Projects Warwick University MSc course London Bridge Associates John Keys Risk Management on Tunnelling Projects Warwick University MSc course

Introduction to Risk Management Identification of tunnelling risks London Bridge Associates Introduction to Risk Management Identification of tunnelling risks Risk analysis and risk assessment tools Introduction to the Risk Workshop

What is risk management? - Definitions London Bridge Associates What is risk management? - Definitions Hazard is something with the potential to cause harm or change the desired outcome Risk is the likelihood of a hazard occurring x consequence of a hazard Risk Analysis is the process of identifying risk factors and the quantification of those factors (estimating likelihood and magnitude of impacts) Risk assessment is the tool whereby risks are evaluated in terms of their likelihood and consequence and mitigation measures identified Risk Mitigation is the process of developing a plan to respond or deal with risk on a project Risk Register is a method for recording the project risks for subsequent management

Risk Assessment process London Bridge Associates Risk Assessment process Hierarchy of Risk reduction Eliminate at Source Control Monitor Initial Risk Consequence Unacceptable Risks Risk cannot be justified except in extraordinary circumstances Tolerable only if risk reduction is impracticable or if the cost is grossly disproportionate to the improvement gained ALARP Zone Residual Risk Tolerable if cost of reduction would exceed the improvement gained Likelihood Negligible Risks

What risk assessment tools are available? London Bridge Associates What risk assessment tools are available? Risk assessments can be undertaken using either Qualitative judgements (high / medium / low risks ) or Quantitative values (numerically as derived from case histories / databases) Consider practicality of assessments Availability of reliable data Diversity of each tunnel’s characteristics

What risk assessment tools are available? Risk Analysis tools London Bridge Associates What risk assessment tools are available? Risk Analysis tools Fault tree analysis Event tree analysis Decision tree analysis

Why do we need Risk Management? London Bridge Associates Why do we need Risk Management? Why do we need Risk Management?

Identification of tunnelling risks? London Bridge Associates Identification of tunnelling risks? The Joint Code states: “Hazards shall be identified and evaluated on a project-specific basis and their consequent risks shall be identified and quantified by Risk Assessments through all stages of a project “ Project Development Stage (conceptual design) Detailed Design Stages Procurement Stage Construction Stage Operational stage for any stipulated maintenance period. 8

Joint Code of Practice for Tunnelling London Bridge Associates Joint Code of Practice for Tunnelling Section 8 – Design Clause 8.3.1. states “The fundamental objective of the design process is that of achieving a robust design, that is a design where the risk of failure or damage to the Tunnel Works or to a Third Party from all reasonably foreseeable causes, and including health and safety considerations, is extremely remote during the construction and the design life of the Tunnel Works. High consequence but low frequency events that could affect the works or a Third Party shall also be considered”

Joint Code of Practice for Tunnelling London Bridge Associates Joint Code of Practice for Tunnelling Section 8 – Design Clause 8.3.4 states “The design process shall include, where appropriate, sensitivity studies to assess the impact of: a) construction tolerances b) variation in geotechnical design values c) variation in materials characteristics d) variation in workmanship and geometry e) methods of construction and the implementation of mitigation/contingency measures f) natural perils exposure in the region of the project such as flood, storm, seismic or tidal effects

London Bridge Associates Joint Code of Practice for Tunnelling Section 8 – Design Clause 8.5.1. states “The Designer shall ensure that adequate construction expertise is available to undertake formal reviews of the design to assess and confirm the appropriateness of the design in terms of Constructability, including health and safety considerations in relation to BS6164”

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Dry Creek Road Tunnel Project London Bridge Associates Risk Management Workshop Dry Creek Road Tunnel Project

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project Background to the project $400m road tunnel in Australia Ring road around the town of Yarra Awali Client designed scheme Funded by state taxes Environmental constraints Golf course Residential areas West Portal in a flood plain

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project Background to the project Detailed design 3km long 110m2 excavated face area Boreholes / seismic surveys / Previous borehole data Tunnel alignment Minimise environmental impact Steep gradients Over burden Utilities High rise luxury hotel Portals positioned to minimise impact Conservation area and a flood plain Old Quarry Geology Hydrology

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project Background to the project Historical Land use Ground water extraction for irrigation Small dwellings still extract water Local brewery Abandoned quarry on west side

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project Background to the project Contractual NEC form of contract with all risks transferred to the Contractor Pain / Gain incentives Design and Construct Contract Novated design - NATM methodology Contractor to price risks 1 month to bid the works

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project Background to the project NATM construction method Alternative designs Cheapest tender submission $400m Contractor lacked resources JV Board decision on passing on risk

Dry Creek Road Tunnel Project London Bridge Associates Dry Creek Road Tunnel Project You are the construction company for the Dry Creek Road Tunnel project. You have a meeting tomorrow with a group of Insurance Companies The Insurer company have asked you to identify all the key risks and convince them that you have the risks under control before they will provide cover to the project Task 1 Your brief is to identify the top risks associated with the project and what control measures you will be putting in place to manage those risks. Rank the risks in order of priority starting with the highest risks first and an explanation why you perceive these risks as priorities. Task 2 Identify the actions and measures the Client and the Designer should have put in place to ensure that the project had the greatest chance of success.