TITLE:
Presentation of Empirical Equations for Estimating Internal Friction Angle of GW and GC Soils in Mashhad, Iran Using Standard Penetration and Direct Shear Tests and Comparison with Previous Equations
AUTHORS:
Pouya Salari, Gholam Reza Lashkaripour, Mohammad Ghafoori
KEYWORDS:
Internal Friction Angle, GW and GC Soil, Direct Shear Test, SPT Test
JOURNAL NAME:
Open Journal of Geology,
Vol.5 No.5,
May
6,
2015
ABSTRACT: Presentation of empirical equations
for estimating engineering properties of soils is a simple, low cost and
widely-used method. One of the major concerns in using these equations is
evaluating their accuracy in different conditions and regions which often lead
to doubts about obtained results. Most of these equations were derived in
special laboratories, different climate conditions and in soils with different
geotechnical and geological engineering properties and were generalized to
other conditions. The main question is that whether these methods are also
applicable to other conditions. Using local equations and narrowing the usage
range of various methods based on each region’s properties are appropriate
methods to solve these problems. This leads to simplified and faster analysis
and high reliability in the obtained results. In this paper, empirical
equations were derived to estimate internal friction angle, based on SPT
numbers of Mashhad City’s soils in Iran, using SPT and direct shear tests
results from 50 samples (25 GW and 25 GC soil samples). The results showed
similar values for predictedφvalues by SPT test andφvalues
determined by direct shear tests.