Preventive conservation engineering practice based on deformation resistance capacity evaluation of heritage buildings.

Urban renewal initiatives have accelerated the frequency of deep excavation projects implemented in close proximity to heritage structures. In soft soil regions, the nonlinear deformation behavior of soil creates substantial risks for the structural safety and long-term preservation of heritage buildings. Focusing on material degradation and pronounced deformation sensitivity of heritage buildings, this paper systematically analyzes the structural response to adjacent excavation through integrated finite element modeling. For a foundation pit excavation near a protected masonry heritage structure, the composite support scheme integrating TRD cement-soil cutoff walls, H-section steel beams, concrete horizontal bracing, and alternate bay excavation techniques effectively limited structural settlement to 2.43-3.13 mm, well below the 3.5 mm damage control threshold. Close correlation between monitoring data and numerical predictions confirmed the reliability of the modeling approach. Furthermore, numerical analysis validates that the code-prescribed soil displacement thresholds serve as upper-bound advisory limits for mitigating heritage structure damage, with case study calibration indicating a 30% reduction is warranted when considering horizontal soil displacement impacts. The developed technical pathway integrating "heritage structure deformation resistance assessment - excavation scheme optimization - preventive conservation implementation" not only provides actionable guidance for heritage-adjacent excavations but also offers transferable value for similar engineering projects.