Static safety evaluation of the main timber frame in ancient residential mindong buildings based on a BMMS

Abstract To address the complexity of roof load calculations in ancient buildings and the of limitations single-method safety assessments, a static safety evaluation approach for timber frames—based on a wearable mobile scanning system (BMMS)— is proposed. First, the BMMS is used to acquire high-precision three-dimensional point cloud data of ancient buildings for digital reconstruction. Next, the roof structure is analyzed in conjunction with regional architectural characteristics, where roof loads and component strengths are determined according to relevant standards. This allows for verification of individual member bearing capacity and subsequent determination of the total roof system load. Finally, based on the modulus of elasticity of wood, the stiffness characteristics of mortise and tenon joints, and the total roof load obtained through the aforementioned process, a finite element model of the timber framework is established. Structural safety is evaluated through static analysis, leading to the formulation of targeted reinforcement measures. The results show that roof components remain within their bearing capacity limits, confirming the rationality of roof dead and live load values. This demonstrates the feasibility of using BMMS-based 3D reconstruction to analyze roof systems, determine force models, and verify bearing capacities. In addition, the effectiveness of the safety assessment method was verified by combining simplified theoretical analysis with finite element analysis. The results showed that while the structure had weaknesses such as melon columns, eaves purlins, through-columns, short beams, and mortise and tenon joints, these weaknesses were all within safety limits, demonstrating good overall stability.