传统的基于表面的数字模型在构建地层时会导致地层模型显示和分析的复杂化，例如在基于剖面的地层轮廓重建时，不同剖面之间轮廓线的分叉问题以及对应和拼接问题等。为了有效地显示在维层状地层的结构，建立了一种基于三棱柱体体元的数字地层模型，同时给出了相关的剖分算法，由于体元的引入，致使相应的剖面和切割算法得到了简化，并解决了工程地质中常见的层状地层模型任意剖面和任意切割的显示问题，也使工程中的多种操作可以在计算机上得到模拟，同时，还列举了基于该模型的相关应用。

It's difficult to build a 3D stratum model based on surface model because the stratum is multi-layer structure. For example, Shape from planar contours is often used in stratum modeling but correspondence problems、tiling problems and branching problems are difficult to be solved. Volume elements can describe both surface and interior of the model. In this paper, a method based on tri-prism is used to build a stratum model. The algorithms of sections and incisions of model are presented here in detail. This method is perfect to model the stratum of layer-structured. Some virtual operations of stratum can be easy realized in computer. The results of application show that the approach introduced here is practical and effective in 3D stratum modeling.