Distribution of the maximum undeformed chip thickness can be approximated as the reproduction of grooves and protrusions of the grinding surface. It plays a very important role in grinding process as it has a close influence on the prediction and modeling of grinding forces, tool life, and surface quality, as well as process stability. In this study, it is investigated from the perspective of the real interference depth of the active abrasive grain to cater to the performance evaluation of the grinding surface. Firstly, image processing techniques combined with three dimensional topography tests are utilized to extract grains' essential characteristics such as the protrusion height, shape, distribution and density. Then, grains' wear is quantified by the probability assignment function and Dempster-Shafer evidence theory. Based on this, the actual interference depth of a single grain is determined. Through grain's kinematics analysis and considering the effect of contact deformation on the actual contact arc length and affective cutting edge density, the distribution of chip thickness in the current grinding area is defined and its distribution model is established. Model's correctness and rationality are verified by grinding experiments of the slider raceway. Results demonstrate the grain's interference depth highly depends on its protrusion height, wear amount and grinding depth which is a primary contributor to the size of undeformed chip thickness, and grains' density, contact deformations mainly affect its distribution. The quantified distribution model of the maximum undeformed chip thickness lays a foundation for the topography modeling and integrity research of grinding surfaces.