Abstract
The influence of any construction work on underground environment should be properly assessed prior to the start of the construction. The evidences used in the assessment and the process of the decision making should be properly documented to ensure the traceability. The difficulty in the assessment of underground environment is arisen from the fact that the hydro-geological information generally includes uncertainties. Evidential Support Logic (ESL) that was recently proposed as an effective tool for the environmental assessment can treat the uncertainties contained in the hydro-geological information. For the reason, ESL was adopted in this study for the evaluation of groundwater flow changes induced by the construction of two underground structures. At the first, the preliminary assessment on the impacts of underground construction to groundwater environment was performed by using ESL with focusing the potential occurrence of groundwater hazards, such as land subsidence, groundwater pollution and so forth. Information on the hydro-geological condition, the water use and the construction plan were used in the assessment. It was found that the effects of the additional survey and the modification of construction plan on the decrease of uncertainties could be well evaluated. At the second, the reliability of conceptual models for groundwater flow analysis around a large underground research laboratory was evaluated by using ESL. The uncertainty on the geometry and the hydraulic feature of a big fault existing around the laboratory was well examined. It was also found that the additional hydrogeological research could be properly planed on the basis of the evaluation. As the conclusion of this study, it can be said that ESL can be well applied to the assessment of construction on the underground environment.
