ABSTRACT
This study investigates the factors contributing to gully formation, specifically focusing on soil properties at the University of Benin gully site. Three soil samples were collected from three points at the gully site namely PT1, PT2 and PT3, at Latitude 5°60'99.3" and longitude 6°40'04.8" . Several tests were conducted on this samples to understand the soil's characteristics, including sieve analysis, specific gravity, Atterberg limits, compaction, and triaxial tests. The test results obtained from soil samples at PT1 at the gully site were as follows:
Triaxial Test:
FRICTION ANGLE: 3.72º, COHESION: 17.50 KN/m²
Compaction Test:
MDD: 1.68g/cm3, OPT.MC: 19.0%
Atterberg Limits:
Liquid limit: 57.71% , Plastic Limit: 27.01%, Plastic Index: 30.71%.
Specific Gravity: 2.59
The test results obtained from soil samples at PT2 at the gully site were as follows:
Triaxial test:
FRICTION ANGLE: 2.40º, COHESION: 23.00 KN/m²
Compaction Test:
MDD: 1.73g/cm3, OPT.MC: 18.3%
Atterberg Limits:
Liquid Limit: 56.97% , Plastic Limit: 27.74%, Plastic Index: 29.23%.
Specific Gravity: 2.60
While the test results obtained from soil samples at PT3 at the gully site were as follows:
Triaxial test:
FRICTION ANGLE: 4.52º, COHESION: 22.50 KN/m² .
Compaction Test:
MDD: 1.67g/cm3, OPT.MC: 17.4%
Atterberg Limits:
Liquid Limit: 60.88%, Plastic Limit: 35.77%, Plastic Index: 25.12%
Specific Gravity: 2.55
The sieve analysis test showed that the soil composition was silty-clay with substantial amount of sand. Based on the results, it was concluded that the low bearing capacity of the soil contributed significantly to the formation of the gully erosion.
