fe1-hw1-spt

FoundationEngineeringI,Spring2010 Homework#IProf.Dr.DerinUral,Res.Assist.Tolgazdoru 22/02/2011

Homework#1:StandardPenetrationTest1. BrieflyexplaintestingproceduresoftheStandardPenetrationTest.Why isthistestperformed?

WhatarethefactorsthataffectthemeasuredNvaluesinaStandardPenetrationTest?Trytogivereasonsforeachfactorandexplainhowtheychangethetestresults.(30pts.)

2. Whichcorrectionfactorsareused intheStandardPenetrationTest?Cantheybeused inallsoiltypes?Listthefactorsaccordingtotheirparametersandexplainhowtheyareused.(20pts.)

3. InaStandardPenetrationTestprocedure,safetypehammerandstandardsamplerareused.Thediameteroftheborehole is80mm.Theresultsofthetestaregiveninthetablebelow.Assumeanaverageunitweightforthesoil, 318.CkN/mn and 320.DkN/msat .TheGWTisatadepthof9m.

a. DeterminethefieldSPTnumber(NfieldorN30)foreachtestdatapoint.(5pts.)b. Usingthepropercorrectionfactors,calculatethecorrectedSPTnumber,(N1)60foreachtest

datapoint.(20pts.)c. Using the correlations between SPTN and soil parameters, give information about the

consistencyorpackingstatusofthesoil layers.Determinethestrengthparametersofthesoillayersusingthesecorrelations.(25pts.)

Depth(m)SPT

Soiltype015cm 1530cm 3045cm1.50 4 2 4 Sand3.00 3 5 4 Sand4.50 4 5 3 Sand6.00 4 4 6 Sand7.50 2 5 4 Sand9.00 3 6 7 Sand10.50 7 1A 9 Siltyfinesand12.00 9 1B 1C Siltyfinesand13.50 1D 1C 1D Siltyfinesand15.00 1A 10+E 10+F Siltyfinesand

Notes:AssumethatyourstudentIDis010040358.YouwilltakeA,B,C,D,EandFasfollows:

010040358 A BCD

A=4B=3

C=5D=8

E=B+D=11F=C+D=13

Remembertociteyourreferences,especiallywhenusingthecorrelations.Thedeadlineforthehomeworkis01.03.2010.