The integration of seismic physical simulation with structural analog modeling represents a significant frontier in experimental geophysics, yet it is hampered by a fundamental material science challenge. Traditional seismic models, fabricated from solidified polymers or resins, are static constructs that lack the dynamic, gravity-driven deformation processes inherent to natural tectonics. Conversely, structural analog models, which expertly simulate faulting and folding using loose granular materials like dry sand, are typically seismically opaque due to intense wave scattering and attenuation at grain-to-grain contacts filled with air. This study was initiated to develop and validate a novel methodological framework that bridges this divide. Its primary objective is to create a physical modeling system wherein the kinematic evolution of geologic structures and the concurrent seismic wavefield response can be observed simultaneously, thereby enabling a direct study of the interplay between tectonic processes and their seismic expression. To achieve this goal, we conducted a comprehensive investigation into the acoustic properties of potential modeling materials. A suite of standard samples, including paraffin-composite materials, mastic, and various water-saturated granular materials (e.g., quartz sand, glass microbeads, brown fused alumina), was prepared using different protocols. A key innovation was the development of an "underwater molding" technique for saturating granular materials, which was systematically compared against immersion and permeation methods. The acoustic characterization was performed using an ultrasonic transmission and reflection testing system. We meticulously analyzed the transmitted waveforms' first-arrival clarity, amplitude stability, and frequency content, as well as the reflection energy and continuity from engineered interfaces within layered models. The research specifically focused on quantifying the effects of two critical parameters: (1) the settling time of the saturated granular pack, which governs gravitational compaction and pore-fluid homogenization, and (2) the particle-size contrast between adjacent layers, which controls the genesis of acoustic impedance contrasts. Our systematic experiments yielded several key findings. First, the underwater molding method proved superior in eliminating entrapped air within pore spaces, thereby producing transmitted signals with sharp first arrivals, high amplitude, and minimal post-signal coda, unlike the oscillatory and noisy signals from samples prepared by other methods. Second, the settling time was identified as a critical control on signal quality. Prolonged settling (up to 72 hours) dramatically enhanced high-frequency (450~600 kHz) content, suppressed low-frequency noise and reverberations, and sharpened the transmitted wavelet. This is attributed to compaction-driven enhancement of grain-contact stiffness and homogenization of the pore-fluid distribution. Third, for interface imaging, the mineralogical density difference between layers was found to be a less effective generator of reflection coefficients compared to particle-size contrast. A significant difference in grain size catalyzes the inter-fingering of fine and coarse grains at the boundary, creating a distinct, dense transition zone with a sharp porosity gradient and a sufficiently high acoustic impedance contrast to produce strong, continuous reflections in seismic profiles. Finally, in a practical demonstration, a multi-layered model over 10 cm thick, constructed with optimized particle-size contrasts and subjected to extended settling, yielded a reflection profile with markedly enhanced continuity, energy, and resolution of internal interfaces, confirming the synergistic effect of compaction and size differentiation. This research successfully establishes a robust and effective methodology for "seismo-tectonic" physical simulation using water-saturated granular materials. The method fundamentally resolves the long-standing trade-off between mechanical realism and acoustic transparency in analog modeling. By providing a material system that deforms under gravitational and boundary stresses while permitting high-quality seismic imaging, it opens new avenues for investigating the dynamic evolution of seismic wavefields throughout tectonic deformation processes, such as thrust faulting or extensional graben formation. The findings offer profound insights for interpreting seismic data from natural unconsolidated sequences, including subaqueous sediments and glacial tills, where similar granular and saturated conditions prevail.