Stability analysis and excavation pattern for Tehran fine grained alluvium



Several studies have been carried out on engineering geology and geotechnical properties of Tehran alluvium with emphasis on cementation, cohesion, strength, etc. However, there are few studies with focus on excavation stability and pattern. This paper focuses on excavation pattern of fine grained alluvium in southern Tehran. Thus, physical and mechanical properties of soil were determined from field investigation and laboratory tests. Afterward, stability analyses were performed using GeoStudio software with Morgenstern-price method based on limit equilibrium. According to the results, the studied region was divided into three zones: D1, D2 and D3 based on excavation stability pattern. Because of low presence of sand in D1 zone, safe excavation depth is more than the others. The excavation depth of vertical wall in D2 and D3 zones is the same, but in deeper excavations in both zones, D3 zone showed more instability