PSI - Issue 78

Nadia Salvatore et al. / Procedia Structural Integrity 78 (2026) 81–88

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Fig. 1. (a) Map of the area of Cherry Hill from Google Terrain; the red diamond depicts the position of the viaduct; the red line represents the surficial trace of the Wasatch fault (modified from USGS https://usgs.maps.arcgis.com/apps/webappviewer/index.html?id=5a6038b3a1684561a9b0aadf88412fcf). (b) Schematic representation of Cherry Hill Interchange. (modified from Price et al., 2000). The Davis and Weber basins were occupied during the late Pleistocene by Lake Bonneville, which was fed by the Bear, Weber, and Provo Rivers until a regression occurred due to the failure of the alluvial Old River Bed threshold. This event caused the lake level to drop during the Bonneville flood around 14.5 ka BP. Following this, Lake Bonneville experienced a continuous regression, eventually falling below 1287 m above sea level during the Holocene. Between approximately 160 and 10 ka BP, the lake underwent abrupt level changes, reaching a maximum of 1550 m above sea level around 20 ka BP. Each variation in the lake level over the last 40 ka is marked by a distinct shoreline (Hart et al., 2004; Oviatt, 2015). Considering these cycles and the long existence of Lake Bonneville, the stratigraphy of the deposits filling the basins is a complex layering of alluvial and lacustrine sediments, with an estimated thickness exceeding 200 m, atop the pre-Bonneville sediments (Lemons and Chan, 1999). These earlier deposits are primarily composed of glacial and alluvial lower Pleistocene materials, more than 200 m thick, overlying Pliocene volcanic tuffs, muds, and agglomerates (Hunt et al., 1953). The Cherry Hill area is situated in the northern part of the Davis basin, predominantly covered by the Great Salt Lake and bordered to the east by the Wasatch Mountain Range. As noted by Lemons and Chan (1999), this region is touched by the distal section of the Weber River paleo-delta, which is distinguished by its fine-grained deposits. Consequently, the surface stratigraphy of the northern Davis area comprises lacustrine and alluvial silt, clay, and fine sand, overlain by alluvial and liquefaction-induced lateral-spread deposits. According to McDonald and Ashland (2008), all these soils are characterized by a V S30 of approximately 200 m/s (Fig.2). Previous studies conducted in the northern part of Farmington have indicated that the groundwater table (GWT) consistently ranges between depths of 1.5 to 5 meters, with surficial deposits exhibiting a median fine content of approximately 53%, despite their non-plastic behavior (Rollins et al., 2012). Based on this evidence, the area is considered potentially vulnerable to earthquakes with an estimated magnitude of up to 7.4. The stratigraphic framework, along with geological and morphological evidence, suggests that the area is prone to soil liquefaction and liquefaction-induced lateral spreading. However, the occurrence of landslides (in the strict sense) can reasonably be excluded due to the distance from the mountain range. Moreover, the presence of soft sediments resting on the stiffer Pre-Bonneville sediments can be responsible for amplification of ground motion. 3. Level 2 analysis: site response and liquefaction/lateral spreading quantitative assessment Given the potential earthquake-related hazards in the area, we conducted a numerical site seismic response analysis and a liquefaction/lateral spreading assessment using simplified methods, as outlined in level 2 of the GETI (Salvatore et al., 2025). It is noteworthy that the subsoil at the Cherry Hill Interchange was reinforced by installing 850 stone columns at depths ranging from 8 to 15 meters (Rollins et al., 2012). Consequently, the liquefaction and lateral spreading assessments were performed considering the soil resistance both before and after this treatment. However, due to the lack of available V S profile data following the subsoil reinforcement, updating the PGA from the site