New methods to improve the assessment of shear wave velocities and seismic hazard parameters in Jeddah city, western Saudi Arabia

Alamri, Abdullah; Fnais, M.; Abdelrahman, Kamal; Abdelmoneim, E.; Alqarni, Hashim

doi:10.1007/s12517-015-2297-2

Cited by 4 publications

(1 citation statement)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are several geophysical approaches for the evaluation of in-situ Vp and/or Vs and obtaining a 1D Vs profile or 2D Vs cross-sections versus depth (e.g., Al-Saigh and Al-Heety, 2013;AL-Saigh & AL-Heety, 2018;Abdelrahman et al, 2021a;2021b). This important parameter can be precisely obtained using surface geophysical methods to evaluate the appropriateness of surface materials for roads, building constructions, and foundations like MASW methods (Socco and Strobbia, 2004;Fnais et al, 2015;Abd El-Aal et al, 2016;Al-Amri et al, 2016;Rehman et al, 2016;Aldahri et al, 2017;Alamri et al, 2020;Igwe and Umbugadu, 2020;Mogren et al, 2020;Naji et al, 2020;Al-Heety et al, 2021;Almadani et al, 2021;Alzahrani et al, 2021;Abdelrahman et al, 2021c;El-Raouf et al, 2021;Abdallatif et al, 2022;Al-Heety et al, 2022;Ayele et al, 2022;Ferguson and Gautreau, 2022;Jusoh et al, 2022). This method is dependable, non-invasive, and cost-effective in engineering practices.…”

Section: Introductionmentioning

confidence: 99%

Estimating shear wave velocity and site characterization of western Riyadh City, Saudi Arabia based on multichannel analysis of surface waves

Abdelrahman,

Saadon,

Qaysi

2024

Front. Earth Sci.

Self Cite

View full text Add to dashboard Cite

The site characterization process is vital for the engineering structures and earthworks. In the current study, a Multi-Channel Analysis of Surface Waves (MASW) was carried out in western Riyadh City, Saudi Arabia. This aimed to determine subsurface geology, material stiffness, and potential weak zones approximately down to a depth of 30 m, and to propose the suitable seismic site characterization for precise foundation design. A total of 30 MASW lines were executed utilizing the Geode digital seismograph equipped with a 24-geophone array of 4.5 Hz. The data acquisition, processing, and inversion were meticulously calibrated to derive shear velocities representing subsurface geological conditions. The Vs30 map, based on estimated values ranging from 443.71 m/s to 639.78 m/s for soil, was prepared for the area. The results of the 1D and 2D Vs profiles tinted small Vs values at shallow depths. The resulting geological model is composed of sand, gravel, moderately weathered limestone, and hard limestone sequence. Analysis of shear wave velocities shows variations, indicating low shear velocity (representing sediments or rocks of low stiffness) juxtaposed with higher velocity layers (indicating rocks of higher stiffness) at depths greater than 10 m. This could imply the presence of a cavity or weak zone. The topmost shear wave velocity zone indicated materials with low Vs values (ranging from 180 m/s to 360 m/s), predominantly associated with stiff materials such as silty sand, gravel, and sandy deposits. The subsequent zone, with 3 to about 10 m depth, was characterized by medium to very dense soil with shear wave velocity values ranging from 360 m/s to 760 m/s, attributed to layers of silty clay and silty sand. At approximately 12 m, a high shear velocity layer (ranging from 760 m/s to 1,500 m/s) was identified, extending to a maximum depth of 22 m, potentially indicative of less weathered or fractured bedrock associated with limestone. While the deepest layer, with very high shear velocity (exceeding 1,500 m/s) beyond 22 m, indicated bedrock associated with hard limestone. The average Shear-wave velocity of soil for the whole study area (Vs30 = 551.2 m/s) suggests that the site can be classified as Class C (Very Dense Soil and Soft Rock) according to the National Earthquake Hazard Reeducation Program NEHRP (National earthquake hazards reduction program, 2001). These results will support, to a great extent, the design of engineering structures in the area of study.

show abstract