Abstract:

District 10 of Ho Chi Minh City is an area of complex engineering geological condition, in which many kinds of soft soil (non-granular) and granular soil are distributed interlaced near the surface, not favorable for construction, especially undeground works. Based on the analysis of the effect of the composition, conditions and spatial relationship within the layers, for the planning of the deep excavation within 20m, it is possible to divide the ground of studied area into 2 types (I, II), 2 subtypes (IIa, IIb) and 7 types of structures (IIa1, IIa2, IIa3, IIa4, IIb1, IIb2, IIb3). Therefore, the results of deep excavation stability analysis show that excavation walls are stable when the excavation is 3m deep with structures type IIa1, IIa2 and IIa4, but if digging to the depth of 6m and over 6m, all the ground structures are unstable; Quicksand does not occur in ground structure type I and will occur in ground structure type II when the deep excavation is interfered or dug into the granular layers.