Estudo comparativo entre a eficiência de sondagens SPT e sísmica rasa para determinação de parâmetros geotécnicos em uma área do município de Caçapava do Sul, RS

Abstract

In the last decades the applied geophysics has been playing a very important role in engineer projects however the enterprises who management these projects are unaware the diversity of geophysics methodologies available. Nevertheless, it's important to highlight that using geophysical methods does not imply quitting in the conventional of investigation. Data coming directly from drilling hole will always be important to help the professional to interpret the geophysical data. The Standard Penetration Test (SPT) is the most popular, habitual and cheaper tool of geotechnical investigation in almost around the world, allowing indicating the density of granular soils, applied as well to identify the consistency of cohesive soils and even soft rocks. One of the most classic methods used in the investigation of land environments is the seismic method, it is a geophysical method that can read the propagation of elastic waves through the geologic layers, characteristics that have a direct correlation with some properties as consolidation/cementing, alteration, compactation, saturation and others more. Thus the seismic generate data that can be integrated with drill holes data to characterize the geology and geotechnique of an area. This paper aims to compare the geotechnical parameters obtained by SPT tests and through shallow seismic surveys using MASW technique (Multichannel Analysis of Surface Waves), to analyze the effectiveness of both the methods in geotechnical projects. Work was performed from geotechnical surveys and geophysical surveys. The results obtained were: identifying different layers of soil and the water table, obtaining soil resistance parameters from geotechnical testing and resistance parameters obtained from geophysical tests. With this work is concluded that the joint application of SPT, electrical resistivity, seismic shallow refraction and MASW proved to be a very effective tool in geotechnical engineering projects, making it possible to correlate the results of all these methods.