The provisions in these guidelines were developed presuming that design parameters required to apply the provisions are established following current Mo DOT site characterization protocols as described in EPG 321.
Specific attention is drawn to EPG 321.3 Procedures for Estimation of Geotechnical Parameter Values and Coefficients of Variation.
Exceptions to this provision shall only be made with specific approval of the Geotechnical Section and shall only be granted if overall stability can be demonstrated as provided in EPG 751.38.7.
The guidelines were established following load and resistance factor design (LRFD) concepts.Similarly, references to provisions within the AASHTO LRFD Bridge Design Specifications are indicated as “LRFD XXX. Footings shall be founded to bear a minimum of 36 in.below the finished elevation of the ground surface.In general, spread footings should be made as close to square as possible.The length to width ratio of footings supporting individual columns should not exceed 2.0, except on structures where the ratio of longitudinal to transverse loads or site constraints makes use of such a limit impractical. rock cuts, river bluffs, etc.) shall be located so that the footing is founded beyond a prohibited region established by a line inclined from the horizontal passing through the toe of the slope as shown in Figure 7188.8.131.52.Additional background regarding development of these provisions and supportive information regarding use of these provisions is provided in the accompanying commentary.Dimensions to be established in design include the bearing depth (depth to footing base) and the footing dimensions shown in Figure 7184.108.40.206.The provisions provided herein are intended to produce foundations that achieve target reliabilities established by Mo DOT for structures located on different classes of roadways.The different classes of roadways/bridges considered include minor roads, major roads, major bridges costing less than 0 million, and major bridges costing greater than 0 million.Footing dimensions shall be established based on project specific requirements, site constraints, and the requirements of this subarticle.Footings shall be sized at the applicable strength and serviceability limit states according to EPG 751.38.3 and EPG 751.38.4; the greatest minimum dimensions established from consideration of each of these limit states shall govern the final design dimensions as long as they exceed the minimum dimensions specified in EPG 751.38.1.