Monitoring and Simulation of Axial Deformation in a High-Rise Twin Tower Connected Building: Fractional Order Viscoelasticity Constitutive Method

This paper investigated the influence of axial deformation on the structural behavior of a high-rise twin tower connected building during its construction. A comprehensive structural health monitoring (SHM) system was deployed, featuring embedded strain sensors within specific vertical members. The SHM system collected strain data throughout the entire construction process, facilitating a detailed analysis of axial deformation progression and variations among vertical components such as walls and columns. Through methodical simplifications and theoretical assumptions, a calculation framework employing concrete shrinkage and creep models was proposed to quantify axial deformation. A comparative analysis was conducted between the calculation results of various models and the measured data, revealing significant discrepancies in the predictions of existing models. Additionally, it was observed that many parameters in these models are challenging to obtain during the design and construction stage. Subsequently, this study introduces a novel time-varying constitutive model based on fractional calculus viscoelasticity to address complexities in existing models and parameter acquisition challenges. The model is characterized by its clear physical interpretation and concise computational parameters, calibrated utilizing measured strain data and Bayesian optimization methods, which significantly enhances prediction accuracy and simplifies the calculation process.