Shirzadi, Ashkan2024-03-212024-03-212023-10https://unbscholar.lib.unb.ca/handle/1882/37769This study thoroughly examines the critical assessment of active earth pressure in unsupported vertical trenches, highlighting the unique challenges presented by unsaturated soil conditions. Traditional theories like Rankine or Coulomb lack effectiveness in such scenarios, highlighting the need to consider factors such as soil type, matric suction, and rainfall. The primary objective is to estimate active earth pressure variations during rainfall events, a critical aspect in preventing sudden failures and ensuring the safety of field workers. Extensive numerical analyses using SEEP/W and SLOPE/W reveal that applying the median resultant force at 20 or 40% of the critical depth maintains factor of safety above 1.2 during prolonged rainfall. These findings provide practical insights to mitigate risks associated with the instability of unsupported vertical trenches in unsaturated soils, ultimately enhancing the overall safety for field workers engaged in such construction operations.xi, 64electronicenhttp://purl.org/coar/access_right/c_abf2master reportOh, Won TaekNasir, OthmanCivil Engineering