A Framework for Risk-Based Cost-Benefit Analysis for Decision Support on Hydrogeological Risks in Underground Construction

Construction below the ground surface and underneath the groundwater table is often associated with groundwater leakage and drawdowns in the surroundings which subsequently can result in a wide variety of risks. To avoid groundwater drawdown-associated damages, risk-reducing measures must often be implemented. Due to the hydrogeological system\u27s inherent variability and our incomplete knowledge of its conditions, the effects of risk-reducing measures cannot be fully known in advance and decisions must inevitably be made under uncertainty. When implementing risk-reducing measures there is always a trade-off between the measures\u27 benefits (reduced risk) and investment costs which needs to be balanced. In this paper, we present a framework for decision support on measures to mitigate hydrogeological risks in underground construction. The framework is developed in accordance with the guidelines from the International Standardization Organization (ISO) and comprises a full risk-management framework with focus on risk analysis and risk evaluation. Cost-benefit analysis (CBA) facilitates monetization of consequences and economic evaluation of risk mitigation. The framework includes probabilistic risk estimation of the entire cause-effect chain from groundwater leakage to the consequences of damage where expert elicitation is combined with data-driven and process-based methods, allowing for continuous updating when new knowledge is obtained

Suitability Analysis of Office Building Design against Maintenance Cost (Case Study of Serayu Opak River Basin Organization, Yogyakarta Province)

This study aims to determine the effect of building design's inaccuracy against the cost of maintenance, by taking the research in Serayu Opak River Basin Organization, Water Resources Field and Water Resources Management Center in Yogyakarta Special Region. The first step is to analyze the inaccuracy of building design based on the result of interview and observation during field survey. The second step is to analyze the cost of building maintenance. The third step is to analyze the maintenance costs used to minimize the effects of the inaccurate design of the building. The result shows the inaccuracy of building design in the form of the use of clear glass without coated glass film and the absence of heat insulator on the roof of the building cause the room to become hot. The installation of rain gutters without vertical pipes, toilet facilities in the entire building is not yet complete, inadequate accessibility for persons with disabilities, and inadequate corridor design. There is a small portion of the maintenance budget used for reducing the impact of building design's inaccuracy, so it can be concluded that the design of the building is less meet the requirements of the Government regulations