Human Factors in Dam Failure and Safety
Recorded on November 10, 2015 (120 minutes)

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Dam failures typically result from interactions of human and physical factors which extend over years or decades.  Understandably, engineers and others involved with dams normally focus on the physical factors.  However, because physical systems such as dams are subject to physical laws and do not make ‘mistakes’, it may be asserted that dam failures (and incidents) are fundamentally due to human factors.  The other side of this coin is that dam safety must then also be fundamentally due to human factors.

Human factors which are primary drivers of failure include (a) tradeoffs associated with non-safety goals (e.g., reducing costs, meeting tight schedules, and political pressures), (b) inherent human fallibility and limitations (e.g., incomplete information, inaccurate models, and cognitive biases) and (c) cognitive effects of having to deal with complexity (e.g., counterintuitive system behavior).  These drivers of failure in turn result in various types of human errors (e.g., mistakes, slips, and lapses) and inadequate risk management (e.g., risk ignorance, complacency, or overconfidence).  Conversely, human factors which contribute to safety include (a) organizational ‘safety culture’, with a corresponding humble and vigilant attitude with regard to preventing failure, and (b) numerous best practices related to general design features of dams, organizational and professional practices, and addressing warning signs.  From the perspective of this framework, failures generally result when the human factors contributing to safety are not sufficient to outweigh those contributing to failure (i.e., demand exceeds capacity).

This webinar will provide a framework for engineers, contractors, owners, regulators, inspectors, maintenance staff, and others involved with dams to systematically think about the human factors which contribute to dam failure and safety, and will include detailed discussion of several of these factors.  Use of the framework will also be illustrated by its application to case studies of dam failures, as well as a case study where failure was prevented by vigilant implementation of best practices.

Irfan A. Alvi, PE is President & Chief Engineer of Alvi Associates, Inc. in Towson, Maryland.  He has 27 years of multidisciplinary experience in structural, water resources, and geotechnical engineering for dams and other infrastructure, involving many hundreds of projects.  For concrete and embankment dams, his experience includes new design, rehabilitation design, inspection, nondestructive testing, forensic investigation, three-dimensional structural analysis, stability analysis, risk analysis, and construction management.  He is a member of the ASDSO Dam Failures & Incidents Committee, and leads the committee’s efforts related to human factors.  He also serves in a similar role on the steering committee for a FEMA project related to dam failures and incidents.  His project involving rehabilitation of Prettyboy Dam in Maryland was the ASDSO 2010 National Rehabilitation Project of the Year.  He has published and presented numerous papers related to dam failures and rehabilitation.

  1. Introduction
  2. General Failure Patterns
  3. Why Human Factors?
  4. Failure vs. Safety
  5. Contributors to Failure
    1. Drivers of Failure
      1. Pressure from Non-Safety Goals
      2. Human Fallibility and Limitations
      3. Complexity
    2. Human Errors
    3. Inadequate Risk Management
      1. Ignorance
      2. Complacency
      3. Overconfidence
  6. Contributors to Safety
    1. Safety Culture
    2. Best Practices
      1. General Design Features
      2. Organizational & Professional Practices
      3. Addressing Warning Signs
  7. Implications for Failure Investigation
  8. Links to PFMA and Risk Analysis
  9. Case Study 1 – Big Bay Dam
  10. Case Study 2 – Ka Loko Dam
  11. Case Study 3 – Prettyboy Dam
  12. Conclusions