Highway Bridge Abutment Spread Footing Design
Highway Bridge Abutment Spread Footing Design
(OP)
For abutment spread footings located near or on slope fill, AASHTO 4.4.7.1.1.4 provides an ultimate bearing capacity formula which contains a modified bearing capacity factor (Ngamaq). Depending on the soil parameters and geometric conditions, this modified bearing factor can be odtained from Figure 4.4.7.1.1.4B. However, if the soil parameters and geometric conditions are not consistent with the plotted variables (i.e. phi=34 deg, j=26 deg, Df/B = 0.5), it becomes your best guess interpretation of what the true Ngamaq values are using linear interpolation. Are there tables available or equations which clearly define what the true modified bearing capacity factors are for any given condition?





RE: Highway Bridge Abutment Spread Footing Design
Graham, J., Andrews, M., and Shields,D.H. (1988). "Stress Characteristics for Shallow Footing in Cohesionless Slopes," Canadian Geotechnical Journal, Vol. 25, No. 2, 238-249.
RE: Highway Bridge Abutment Spread Footing Design