地質與地層模型不確定性之量化及其應用之整合型研究(1/4)

A reasonable geological model and the spatial distribution of its parameters are crucial for (i) geo-resourcesdevelopment; (ii) geo-environment protection; and (iii)geo-hazard mitigation. However, the uncertainty in theestablished geological model is seldom characterized and communicated to the engineer called upon to perform riskbased engineering. This research tackles the challenges in quantifying the geological model uncertainty andpropagating this uncertainty in selected applications of urgent national interest. Specifically, the study focuseson the effect of sedimentary environments on the scale of fluctuation in stochastic Markov random field theory formodeling the subsurface stratigraphic configurations. This four years projects will focus on four applications:(1) Vs30 mapping; (2) liquefaction potential and risk; (3) groundwater related hazards management table; (4)performance-base design of rock slope engineering. Taipei Basin is selected as the study region. The stochasticMarkov random field modelling tool will be used to quantify the geological uncertainty and propagation of uncertainties to applications. The main achievements of the past 9 months are listed as follows:(1) Complete the collection of database required. The database will deliver to the sub-project after the qualitycheck and data analysis in the second year. (2) The coupled geological and parametric random field modeling tool has been developed. This tool has been used for liquefaction analysis and will be used for geologicaland parameter uncertainty propagation to different application (Vs30, groundwater flow monitoring, and rockslope stability). From scientific view point, we will focus on the reasons why the new approach superior to thetraditional approaches. (3) We well use the Walther’s law and maximum likelihood estimation to calibrate the parameter K required for random filed modeling. This parameter is dominated by the sedimentary structure. Next step, we will calibrate this parameter using borehole data of selected zones in Taipei Basin with different sedimentary environments. Based on our study, we can correlate the K parameter and sedimentary environments. This result will be a very important database for random field modeling. (4) The first version of Vs30 map and groundwater flow modelling of Taipei Basin has been delivered. These map will be extensively improved in the following three years with consideration of geological and parameter uncertainty. The liquefaction potential map of Taipei Basin will be provided first at second year, based on the borehole data database developed by this project. (5) The geological model of the site for rock slope stability study has been developed via field works, borehole data, and LiDAR data. The reliability of the geological model has been confirmed. The influence of bedding plane orientations on slope failure probability has been evaluated and the risk of the studied rock slope will highly relate to the geological model uncertainty. The hydro-mechanical coupling effect on rock slope stability will be considered in the coming years. Different numerical models will be utilized to evaluate the failure probability and the influence of geological, ground, and geotechnical model uncertainties on rock slope stability can be studied integrated.