Soil Profile Type Reference for Second Congressional District in the Province of Sorsogon, Philippines

This study compiled the soil profile type in the nine municipalities of the second congressional district in the province of Sorsogon, Philippines. The soil profile types are parameters for seismic response coefficient used in the determination of design base shear in seismic analysis of buildings. Standard Penetration Test (SPT) results obtained from Department of Public Works and Highways (DPWH) Sorsogon Second District Engineering Office (DEO) subsoil exploration file were used to estimates these parameters. A total of 564 boreholes were analyzed and computed the average field standard penetration resistance N prior to assigning soil profile type based on the categorization procedure set forth in National Structural Code of Philippines (NSCP). Based on the result of the study, it was found out that in several locations in the Sorsogon second district, soil profile type varies.  Different soil profile type is scattered all throughout in each municipality. Areas that have stiff soil profile have tuff, coralline or boulders underlying materials. Thus the use of coring on this area in advancing borehole for geotechnical investigation is recommended. Also, soil showing soft profile type must have established comprehensive geotechnical analysis in order to attain proper geotechnical characteristics. Furthermore, for proper evaluation of the soil profile type and other geotechnical parameters, SPT should be done for at least 30 m depth as suggested in the National Structural Code of the Philippines. This study can provide engineers with a reference guide in estimating the soil profile type within the second congressional district in the province of Sorsogon. Also, this study may provide preliminary data in conducting specific sub-surface exploration in any place in the municipality of Sorsogon second district.