# Pedestrian Comfort Analysis and Parameterized Optimization Design for Raised Floors
## 2 Material and Methods
### Research Process  
The research consisted of three steps.  
1. Model analysis  
In this step, a finite element simulation model of the raised floor was developed to calculate the theoretical modal frequencies and mode shapes. Following this, the accuracy  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Standard** & **Assessment Indicators** & **Classification** & **Limits** \\ \hline Code for design of concrete structures (GB 50010-2010) [35] & *\(f_{1}\) & \begin{tabular}{c} Residential and apartments \\ Offices and hotels \\ Large-span public buildings \\ \end{tabular} & \begin{tabular}{c} \(f_{1}\geq 5\) Hz \\ \(f_{1}\geq 4\) Hz \\ \(f_{1}\geq 3\) Hz \\ \end{tabular} \\ \hline Technical specification for concrete structures of tall building (JGJ 3-2010) [36] & *\(a_{p}\) & \begin{tabular}{c} Residential and office \\ Shopping malls and indoor corridors \\ \end{tabular} & \begin{tabular}{c} \(f_{1}\geq 4\) Hz \\ \(a_{p}\leq 0.05\) m/s\({}^{2}\) \\ \(f_{1}\geq 4\) Hz \\ \(a_{p}\leq 0.15\) m/s\({}^{2}\) \\ \end{tabular} \\ \hline Technical specification for steel structure of tall building (JGJ 99-2015) [37] & \(f_{1}\)\(a_{p}\) & \begin{tabular}{c} Residential and office \\ Shopping malls and indoor corridors \\ \end{tabular} & \begin{tabular}{c} \(f_{1}\geq 2\) Hz \\ \(a_{p}\leq 0.07\) m/s\({}^{2}\) \\ \(f_{1}\geq 2\) Hz \\ \(a_{p}\leq 0.02\) m/s\({}^{2}\) \\ \end{tabular} \\ \hline Vibrations of steel-framed structural systems due to human activity (AISC811-16 Design Guide 11) [38] & \(f_{1}\)\(a_{p}\) & \
\begin{tabular}{c} Residential and office \\ \(a_{p}\leq 0.20\) m/s\({}^{2}\) \\ \(8\) Hz \(\geq f_{1}\geq 4\) Hz \\ Walk : \(a_{p}\leq 0.15\) m/s\({}^{2}\) \\ Rhythmic movement: \\ \(a_{p}\leq 0.20\) m/s\({}^{2}\) \\ \end{tabular} \\ \hline Eurocode—Basis of structural design (EN 1990: 2002/A1: 2005) [39] & \(f_{1}\)\(a_{p}\) &
\begin{tabular}{c} \(f_{1}\geq 5\) Hz \\ \(a_{p}\leq 0.50\) m/s\({}^{2}\) \\ \(f_{1}\): The first order vertical load natural frequency. *\(a_{p}\): The peak vertical vibration acceleration limit. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of floor vibration comfort criteria limits.  
of the model was verified through comparison with experimental modal frequencies. Through cross-validation of experimental and theoretical modal analyses, the first-order vertical resonance frequency of the raised floor was determined.  
2. Dynamic response analysis  
In this step, we aimed to identify the most vulnerable deformation zones within a raised floor subjected to vibrations through an analysis of its mode shapes. By incorporating permanent loads, effective distributed live loads, and walking excitation loads into a finite element model, the dynamic response deformations of the structure could be obtained. Subsequently, the peak acceleration at the most critical point of the raised floor during vibration was determined.  
3. Optimized design  
In this step, a parametric design model of finite element analysis was constructed and configured to perform size optimization on the geometric shape of a raised floor, achieving parametric design of structural layout. By specifying optimization objectives and constraint conditions, a multi-objective optimization algorithm was employed to obtain the Pareto solution set. The aim was to achieve the optimal trade-off design between comfort in walking on the raised floor and its heat transfer performance.