為了解基地的地層分布狀況與其土壤的工程特性，以供設計及施工時之參考，常於基地辦理現地鑽探調查，在鑽探初期可就已有之鑽探資料先行了解鑽孔佈設間距及數量之合理性，以求在鑽探成本控管以及詳細了解現地土層參數變化取得最佳平衡。 在本研究已完成探討北台灣某三處基地之地層參數的空間變異性，A、B、C基地鑽孔數目分別為50個左右、30個左右、20個左右，並依現地鑽孔資料中之孔隙比、塑性指數及細粒料含量與不排水剪力強度和卵礫石層的相關參數等，以半異數函數描述各場址的土壤參數所對應的半變異圖，並從半變異圖得知影響範圍，以其空間變異特性判斷是否須在現地增設鑽孔或是縮小鑽孔間距等，可有效控制工程上的成本。主要結果為若參數受空間變異性的影響，其擬合結果之影響範圍若小於原有鑽孔的間距，可考慮增設鑽孔或是縮小鑽孔間距。 ;In order to understand the stratigraphic distribution of the soil engineering properties at a construction site for design and construction, it is necessary to conduct geotechnical investigation at the site. In the early stage of drilling, we can first understand possible distribution of the soil layers based on the existing drilling data. However, if the existing drilling information is not enough, it is very subjective to determine proper borehole numbers following only the construction codes. In this study, the authors explored the spatial variability of the soil formation parameters of three construction sites in northern Taiwan. The number of drill holes in construction A, B and C is about 50, about 30 and about 20, respectively. According to the borehole data, the semi-variogram corresponding to the soil parameters at each site was described by the semi-variogram functions. From the semi-variogram the range can be obtained and deemed as the range of influence., Therefore, the range can be compared to the existing spacing between the boreholes. If the range is less than the existing borehole spacing, it is regarded that the spacing may be reduced in order to obtain a more representative soil boring information On the contrary, if the spacing is less than the range under a given soil parameter, this indicated that the spacing may be proper to obtain representative soil parameters.
