## 2 Materials and Methods  
### Site Profiles  
The current study assessed amplification characteristics using comprehensive data from soil investigations conducted at 18 distinct locations, encompassing a total of 51 boreholes in the Gwadar District. These investigations, carried out by the National Highway Authority and consulting firms for various construction projects, provided essential geotechnical information, including standard penetration test (SPT-N) values and laboratory results. The stratigraphy of the region is composed of fine-grained soils with plasticity ranging from non-plastic to medium plastic, generally overlain by layers of poorly graded sand or silty sand. To effectively represent the geotechnical variability across the study area, six representative site profiles were chosen based on key geotechnical parameters and stratigraphy, reflecting the broader soil configurations within the Gwadar region, as shown in Figure 3.  
In brief, Site-1 (S-1) primarily comprised loose silty sand underlain by a dense layer of poorly graded gravel with sand. Site-2 (S-2), located at a seasonal lake bridge site on the East Bay Expressway of Gwadar Port, consisted of silty sand and sandy silt, underlain by extremely weak to very weak, light grey, moderately weathered mudstone. Site-3 (S-3), a high school building site, was composed of poorly graded sand, followed by a dense layer of poorly sorted gravel. Site-4 (S-4), a building site, consisted of loose to medium dense silty sand over hard medium-plastic lean clay. Site-5 (S-5) and Site-6 (S-6), located near the desalination plant and Expo Center, featured loose to medium dense silty sand over layers of clay and silt. The groundwater table was found near the surface and ranged from 0 m to 8.23 m across the site profiles. The stratigraphy of the site profiles investigated and the corrected standard penetration test values (SPT N\({}_{60}\)) of the study area are summarized in Table 2. \begin{table}
\begin{tabular}{c c c} \hline
**Project Name** & **Estimated Cost (USD)** & **Project Objectives** \\ \hline Port and Free Zone Development & 300 million & To facilitate trade and economic activity. \\ \hline Gwadar Eastbay Expressway & 179 million & To facilitate the movement of goods, services, and people, and help to promote regional trade and economic activity. \\ \hline Pak–China Friendship Hospital, Gwadar & 100 million & To enhance healthcare infrastructure in the region. \\ \hline Desalination Plant (1.2 MGD) & 12.7 million & To provide a reliable source of potable water for the people of Gwadar and the surrounding areas. \\ \hline New Gwadar International Airport & 230 million & To provide a modern and efficient airport facility that can support the economic development of Gwadar as a strategic hub for trade and commerce. \\ \hline
300 MW Coal-Fired Power Project & 542.32 million & To provide a reliable source of electricity to support the development of businesses and industries in Gwadar. \\ \hline \end{tabular}
\end{table} 
Table 1: Major completed and ongoing projects in Gwadar region, adapted from Ref. [49]. In this study, soil stiffness variations with depth were computed using shear wave velocity (Vs) profiles obtained from the soil investigation data. These Vs profiles facilitated site classification according to the code guidelines. Subsequently, the profiles were directly incorporated into seismic site response analyses to assess the amplification characteristics of various site classes within the study area.