Writers : Soveyzi,Zeynab;Supervisor:H,Gh,Lashkaripour.H,Sadeghi
Refference : M.Sc.Thesis _ Ferdowsi University,Mashhad
Publishing Year : 1386

Abstract :

This research represents two analytical, numerical and experimental approaches for identifying soil profile characteristics including shear wave velocity, damping ratio and unit weight using seismic response of soil profile (transfer function). These methods are inversion of transfer function and inversion of equivalent linear method respectively.
In the first method, the transfer function is defined in terms of the different parameters of the layers constituting the soil profile including thickness, damping ratio, shear wave velocity and unit weight. Then, during the inversion method, by minimizing least squares errors between this function as the calculated data and experimental function as the observed data, parameters including shear wave velocity, damping ratio and unit weight of objective soil profile are determined.
In second method, with having seismic record on rock, transfer function is defined by equivalent linear method. In this method transfer function is computed using damping ratio and shear modulus that are compatible with strain level induced in soil profile by earthquake. Shear wave velocity and unit weight of the layers constituting the soil profile determined by minimizing least squares errors between computed function and experimental function related to same earthquake.
Validity of two approaches is investigated with applying them on 16 boreholes in the Mashhad plain. Before doing the inversion, the transfer functions of each profile are computed using its geotechnical data in one dimensional soil profile.
These used in inversion problem as observation data.
Analysis of the results of the both inversion methods and comparison them with geotechnical data of the boreholes as actual models reveal that soil profile characteristics can be determine by inversion of seismic response of soil profile as low cost and fast approach. Significantly in cases which nature of unknown parameters is same, accuracy of results for all layers is efficient.

Subject List : soil profile