PSI - Issue 33

Anas Ibraheem et al. / Procedia Structural Integrity 33 (2021) 942–953 Anas Ibraheem, Yulia Pronina / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 7. Comparison between the bending moment diagrams according to the three considered cases.

As seen from Fig. 7, the effect of footings settlements (consolidation settlement) in analysis can lead to noticeable difference in the prediction or results (moment values flipped from negative to positive in critical sections). This is greatly affect the design of the elements sections and, consequently, the stability of the structural elements. This difference can be explained by the following reasons:  The quality of the ground soil is inadequate. This requires taking measures to improve the properties of the soil and carry out preparatory work before laying the foundations (it is up to the geotechnical engineer to choose the best option): Increasing the depth of foundations; groundwater drainage; soil components improvement; the use of sheet piles; the use of sand piles; removing and replacing of weak soil; static soil compaction; dynamic compaction of soil; jet grouting; soil injection.  Dimensions that have been chosen for the foundations lead to significant difference in pressure distribution under adjacent foundations. This requires changing their dimensions or changing their type (replacing the shallow foundations (footings) on general raft (mat) slab foundation for the all structure). For example, to reduce the differential settlement values we have changed the dimensions of the footings in the form showing in Fig. 8. This form of footing locations and dimensions gives the values of foundations settlements shown in Table 4. Table 4. The new settlements (mm) at elevation 1 in the foundations located under the selected beam Settlement The grid line name 1-A 1-B 1-C 1-D + 36.2 36.4 36.3 36.4 This form reduces the differential settlements between the adjacent foundations. According to it, the bending moment diagrams are approximately equal in all cases (this is evident in Fig. 9).