Structural Deformation Assessment of Brick and Stone Pagoda Heritage base on HPDM Spatial Characteristics Analysis

Traditional surveying and finite element simulation have problems such as low efficiency, insufficient accuracy and inconvenient operation in the deformation assessment of brick and stone pagoda. To meet the needs of overall pre-assessment in the early stage of heritage protection, this study proposes an efficient structural pathology method based on the spatial characteristics analysis of high-precision digital models (HPDM). By fusing multi-source data to construct a refined three-dimensional model, and combining the octree algorithm for model lightweighting and solidification processing, the Rhino+Grasshopper platform is used to achieve layer-by-layer slicing and centroid extraction. Based on Python/NumPy, six structural indicators such as horizontal displacement, spatial displacement, tilt angle and torsion angle are calculated to achieve quantitative assessment and visual expression of the deformation of brick and stone pagoda. Taking five Song Dynasty brick and stone pagoda in Guangdong Province as examples, the effectiveness and reliability of this method in overall tilt judgment, tilt mode classification and pathology area identification are verified. The results show that the spatial characteristics analysis method significantly improves the assessment efficiency while ensuring accuracy, providing a scientific basis for the rapid screening and precise protection of brick and stone pagoda heritage, and offering a new idea for studying the correlation between structural pathologies and material pathologies.