# Pedestrian Comfort Analysis and Parameterized Optimization Design for Raised Floors
###### Abstract  
Pedestrian comfort is not only related to the health of the human body, but also directly impacts the efficiency and lifespan of building materials. Raised floors have more complex geometric characteristics and structural dynamic properties compared to traditional flooring, which necessitates an analysis of pedestrian comfort. This study explores four different configurations of raised floors in prefab bathroom units to evaluate their pedestrian comfort. Through theoretical and experimental modal analysis, the natural frequencies and potential deformation areas are identified, enabling the calculation of peak acceleration of the raised floors under walking excitation. The study then quantitatively assesses the pedestrian comfort of raised floors based on natural frequency and peak acceleration measurements, proposing an optimization design method using a multi-island genetic algorithm (MIGA). By adjusting parameters such as the support leg distance, beam shape, and support board surface layer thickness, an optimal balance between pedestrian comfort and heat transfer performance is achieved. Through the integration of simulation and experimental techniques, the study presents an efficient and cost-effective optimization design method for raised floors and explores the impact mechanism between design variables and pedestrian comfort performance. r 2024  
pedestrian comfort in relation to raised floors possesses both theoretical significance and practical implications. In recent years, there has been significant advancement in the design and performance assessment of raised floors. The \"general specification for raised access floor for electrostatic protection (GB/T 36340-2018)\" [9] classifies raised floors into two categories based on their ability to bear loads: four corner bearings and four jamb bearings. These raised floors are commonly seen in industrial environments such as data centers, laboratories, communication rooms, central control rooms, and electromechanical production workshops [10]. Studies by various researchers have analyzed the impact of raised floors on server heat dissipation and telecom equipment performance [11; 12; 13], as well as the air permeability in cleanroom settings and indoor particulate concentrations [14]. With the growing popularity of prefabricated constructions, raised floors are increasingly being used in office, hotel, and residential settings for decorative purposes. While existing research primarily focuses on the influence of raised floors on building energy consumption [12; 13; 15], there remains a gap in the research pertaining to their effect on pedestrian comfort. The critical role played by the structural dynamic characteristics of flooring in ensuring a comfortable walking experience has been highlighted in recent research [16]. To avoid resonance phenomena arising from pedestrian loading, it is crucial to identify the natural frequencies of the structure through modal analysis [17]. Experimental modal analysis techniques, including the frequency domain decomposition method [18; 19] and the natural excitation technique [20; 21], are commonly employed in determining these natural frequencies. Throughout the various stages of floor production, construction, and use, the boundary conditions progressively evolve from a free state to being encased within an elastic layer, and ultimately to being firmly integrated into the building structure. This transition significantly alters the dynamic structural performance of the floor. The gradual stabilization of the boundary conditions, coupled with the influence of wall systems and the imposition of furniture loads, contributes to an increasing damping ratio. Additionally, the constraint of free long edges and the assimilation into an expanded flooring system result in elevated frequency values, with the complexity of vibration modes becoming more pronounced [6; 22].