Degree Of Lateralization Of Tropical Soils And Their Implications For Road Construction (Case Of Tis Esat Road Project, Bahir Dar)

Abstract

An Increase In Construction And Material Use In Tropical Environments Has Made Way For Engineering Knowledge Of Related Basic Properties Of Soils Within Those Areas. One Such Soil Found Abundantly Is The Lateritic Soils. The Main Objective Of This Research Work Was To Study The Degree Of Lateralization Of Tropical Soils And Their Implication For Road Construction. The Objectives Of This Study Were Satisfied By A Series Of Standardized Geotechnical And Geochemical Laboratory Tests Of Lateritic Soils Which Are Observed To Occur In The Bahir Dar-Tis Esat Road Project. Five Sites Were Randomly Chosen Throughout The Road From Which Disturbed And Undisturbed Lateritic Soil Samples At A Depth Of 0.6m And 1.5m Were Collected. Comparison Of The Determined Engineering Properties Was Compared With Properties Of Similar Studies Done On Lateritic And Laterite Soils With Local Researchers And Found In Africa. The Findings Show Particle Size Distribution Of The Soil Throughout The Study Area Is Very Similar. While Most Classification Could Be Said As Highly Plastic Inorganic Soils And Some Are Gravels Falls Above And Below A-Line. Nmc Range Between 4.53 To 12.2%. Average Mdd And Omc Were Found To Be 1.563 And 20.58 Respectively. The Specific Gravity Ranges Between 1.75 To 2.69 With An Average Of 2.23. Ll, Pl, And Pi Range Between 42 To 86.3%, 28.38 To 38.4%, And 13.12 To 49.7% Respectively. The Soaked Cbr Ranges From 1.22 To 10.41% And The Corresponding Swell Percent Ranges From 1.49to 14.36% Respectively At 65 Blows Of The Modified Proctor. Ucs Test Is Found Between 40.42 To 146.26kpa. The Silica To Sesquioxide Ratio Of The Most Geochemical Test (Complete Silicate Analysis) Shows Between 1.33 And 2, Indicated That They Are Lateritic Soils. The Free Swell Result Gives An Average Value Of 56% Indicates A Medium Potential Of Expansiveness. Generally, The Soils Are Classified As A-7-6 To A-7-5 Subgroups Of Aashto Classification. According To The Material Requirement Of Era-2013, Only Test Pit C (Sample C-1 And C-2) Satisfies To Be Subgrade Or Embankment Material. Finally, Based On The General Findings Of The Study, Suitable Recommendations And Conclusions Have Been Forwarded.