Prediction of Shear Wave Velocity in Underground Layers Using SASW and Artificial Neural Networks

Andisheh Alimoradi,Hashem Shahsavani,Abolghasem Kamkar Rouhani

doi:10.4236/eng.2011.33031

Andisheh Alimoradi, Hashem Shahsavani + Show 1 more

Open Access

https://doi.org/10.4236/eng.2011.33031

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Journal: Engineering	Publication Date: Jan 1, 2011
Citations: 10	License type: CC BY 4.0

Affiliation: University of Shahrood

Abstract

This research aims at improving the methods of prediction of shear wave velocity in underground layers. We propose and showcase our methodology using a case study on the Mashhad plain in north eastern part of Iran. Geotechnical investigations had previously reported nine measurements of the SASW (Spectral Analysis of Surface Waves) method over this field and above wells which have DHT (Down Hole Test) result. Since SASW utilizes an analytical formula (which suffers from some simplicities and noise) for evaluating shear wave velocity, we use the results of SASW in a trained artificial neural network (ANN) to estimate the un- known nonlinear relationships between SASW results and those obtained by the method of DHT (treated here as real values). Our results show that an appropriately trained neural network can reliably predict the shear wave velocity between wells accurately.

Highlights

Shear wave velocity estimation is an important task due to its application in evaluating sub surface response to earthquakes, soil improvement, and the strength of the surface structures’ foundation
This research aims at improving the methods of prediction of shear wave velocity in underground layers
Since Spectral analysis of surface waves (SASW) utilizes an analytical formula for evaluating shear wave velocity, we use the results of SASW in a trained artificial neural network (ANN) to estimate the unknown nonlinear relationships between SASW results and those obtained by the method of Down Hole Test (DHT)

Summary

Introduction

Shear wave velocity estimation is an important task due to its application in evaluating sub surface response to earthquakes, soil improvement, and the strength of the surface structures’ foundation. Two common methods for determining shear wave velocity profile in sub surface layers are Down Hole Test (DHT) and Cross Hole Test (CHT). In these methods we need to drill bore holes. Bore hole drilling is a destructive, expensive and time consuming task. A proper non-destructive alternative for these methods is needed. Spectral analysis of surface waves (SASW) method is a non destructive procedure which gives shear wave velocity using seismic surface waves [1]

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