Investigation on some of the Engineering Properties of Soil in Teppi Town

Abstract

Nowadays, the construction of civil engineering structures is increasing from time to time in Teppi Town as it is a developing town. For this infrastructure, a geotechnical investigation is mandatory to have a safe structure. Currently, there is no enough detailed geotechnical investigation that was done for Teppi town. Therefore, this research was aimed to give a clue on Investigation on some of the engineering properties of soil found in Teppi town. This study has addressed analyzing the visual identification, index property determination, compaction characteristics, consolidation, and shear strength analysis by taking the disturbed and undisturbed samples from ten test pits. The sampling procedure and tests were based on American society for testing material (ASTM) manual standards. A selected test pit was dug out with hand tools of a disturbed and undisturbed soil sample then taken to the laboratory to test the index and engineering properties of the study area, the laboratory test types, which was conducted at the average depth of 1.5m and 3.0m were moisture content, Atterberg limit, sieve analysis, standard compaction, etc. The result of the study shows that the natural moisture content varies from 32.18% to 59.45%. The specific gravity varies from 2.53 to 2.78. The majority of soils were categorized as fine-grained soils from which more than 50% of the particle sizes are smaller than 0.075 mm except from two test pits in which they are coarse-grained soil. The liquid limits range from 55% to 104% and plastic limits vary from 25% to 57%. The free swell ranges from 40% to 100%. Based on the free swell index result most of the study area soil was experiences a very high degree of expansiveness, and two tests pit degree of expansiveness belong high. The investigated sample has an undrained shear strength value ranging from 72.11 kPa-131 kPa as shown by the unconfined compression strength test. The compression index value ranges from 0.28 to 0.40. Within the depth of the exploration, the compaction test shows that the maximum dry density of the teppi soil is between 12.96 KN/m3 to 15.45 KN/m3 and the optimum moisture content ranges from 19.5% to 35.80%. A comparison was made in is this study with previously done research in other parts of Ethiopia. The comparison indicates that the engineering properties of these soils of the study area soil lies within the range of different researchers in the other part of the country