PSI - Issue 84

A.A. Khalil et al. / Procedia Structural Integrity 84 (2026) 983–990

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Fig. 14. Pier‑inclusive demolition response.

Nonetheless, lateral displacements at pier tops reached ≈ 273 mm, and bending moments peaked around ≈ 3461 ton·m in severe runs with high friction or reduced staging. Seven sensitivity runs covered: Bearing pad friction ( μ≈ 0.1 to 0.8) and shear stiffness variations; Soil stiffness changes; Demolition staging. Code‑based flexural capacities were occasionally exceeded in envelope checks for some piers, but pushover analyses, applying controlled top displacement until loss of equilibrium, showed ultimate capacities consistently above the dynamic demands. Shear capacities were comfortably adequate against maximum recorded shears, and soil property variations exerted minimal influence on pier response compared to bearing friction and staging. These results support the feasibility of Method 3 under conservative assumptions, provided exclusion zones, monitoring, and design sequencing are maintained throughout demolition. 6. Conclusions This integrated study demonstrates that high‑fidelity structural analysis, implemented via the Applied Element Method in ELS environment, provides a decisive framework for selecting and tailoring demolition methodologies to the actual condition of the structure and site constraints. By explicitly modeling prestress continuity, diaphragm/slab connectivity, bearing behavior, pier-soil interaction, and observed degradation (inactive tendons, cracked interfaces), the analysis ensure evidence‑based demolition pl anning, reducing risk and optimizing cost and schedule. In particular: Method 1 was found to be the preferable method for navigable accessible spans given that reactions and stresses are predictable, provide larger reserve capacity, and sensitivity to tendon degradation is reduced due to direct support. Method 2 was considered when mechanical ground access was feasible provided mid‑span cutting and targeted retention of diaphragm portions to manage vibration and maintain transverse load sharing. Method 3 was found the most cost-effective in case of spans with limited tendons degradation, provided that bearing friction, deconstruction sequence and exclusion zone are controlled. The analysis provided specific thresholds such as deflection ratio limits, allowab le vibrations, seat length and gap monitoring as well as jack‑up reaction envelopes that can be translated directly into filed monitoring to ensure effective risk mitigation. Under the studied damage states and boundary conditions, structural analysis provided cost-effective demolition methodologies through sequencing refining tailored to the bridge’s actual structural behavior. 7. References Applied Science International LLC. (2004). Technical Manual of Extreme Loading for Structures. Durham, NC. Canadian Standards Association. (2020). Canadian Highway Bridge Design Code - CSA S6-14. Grunwald, C., Khalil , A. A., Schaufelberger, B., Ricciardi, E. M., Pellecchia, C., De Iuliis, E., & Riendel, W. (2018). Reliability of collapse simulation – Comparing Finite and Applied Element Method at different levels. Engineering Structures, 265-278. Maekawa, K., & Okamura, H. (1985, May). The Deformational Behavior and Constitutive Equation of Concrete using Elasto-Plastic and Fracture Model. Journal of the Faculty of Engineering, pp. 253-328. Tagel-Din, H., & Meguro, K. (2000). Applied element method for dynamic large deformation analysis of structures. International Journal of the Japan Society of Civil Engineers (JSCE)(17), 215-224.

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