Correlation of SPT and Seismic Refraction Tests to Obtain Dynamic Soil Parameters. Palestina, Guayas-Ecuador

Abstract

Obtaining dynamic soil parameters is key to assessing hazards in civil works. Soil characterisation contemplates field measurements and interpretations that require a comprehensive analysis for the design to offer guarantees. The Palestina-Ecuador canton is affected by heavy rains in winter, cutting off more than 16,000 inhabitants. The integral study of effective techniques for constructing bridges is a priority for the sector's economic development. This work aims to obtain dynamic parameters through the correlation of tests (Standard Penetration Test) SPT and seismic refraction for the characterisation and viable design of civil works in the Palestina-Ecuador canton. The research methodology consists of three phases: 1) Approach to fieldwork by gathering basic information; 2) Field measurements (SPT tests and seismic lines) and laboratory; 3) Correlation and analysis P-wave seismic velocity (Vp) and SPT for determination of dynamic parameters. The subsoil presents Quaternary alluvial sediments, where soft clays and loosely compacted silts predominate. The execution of 140 SPT tests in the laboratory of eight perforations allowed the correlation with six seismic refraction lines in the four precincts of interest for the construction of bridges: El Carmen, La Corona, Las Peñas, and Lagarto estuary, the field tests were distributed. The technical analysis resulted in a linear regression equation that correlates N60-Vp and the establishment of in-situ dynamic parameters (Cohesion and internal friction angle). These calculations made it possible to formulate a correlation equation that presents a validated method for this canton, due to data correlation; providing a tool that allows a detailed and economic characterisation for the rural sector. However, it is necessary to establish other places of analysis to strengthen the proposed equation.

Geotechnical Characterization for Territorial Planning of a Special Economic Zone at a University Campus in Ecuador

“…Data processing was performed using IXREFRAX software. The soil strata were defined based on the anomalies detected in the velocity of Pwave arrival (Vp) [41,42]. The lithology was determined using typical wave-speed values corresponding to different types of materials according to the international standards of the American Society for Testing and Materials (ASTM) D5777-18 [43].…”