If the foundations of all the columns of a structure are designed on the total live and dead load basis, then
A. There will be no settlement of columns
B. There will be no differential settlement
C. The settlement of exterior columns will be more than interior columns
D. The settlement of interior columns will be more than exterior columns
Answer: Option D
Solution (By Examveda Team)
Concept: When all footings are proportioned on the basis of total load (dead + full live load), the design aims to keep the same allowable soil pressure under every footing at the notional maximum loading condition.Reality of loading: In service, the live load is not fully present everywhere at the same time, and interior columns generally have larger tributary areas than exterior columns. Hence, interiors attract higher actual loads more often.
Resulting behavior: Because interior footings experience higher sustained/actual pressure relative to exterior footings, they undergo greater compression of the supporting soil.
Conclusion: Differential settlement occurs with the interior columns settling more than the exterior columns.
This Question Belongs to Civil Engineering >> Concrete Technology And Design Of Concrete Structures
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Comments (3)
In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively
A. Compressive and tensile
B. Tensile and compressive
C. Both compressive
D. Both tensile
Critical section for shear in case of flat slabs is (adopting standard notations)
A. At a distance of effective depth of slab from periphery of column/drop panel
B. At a distance of $$\frac{{\text{d}}}{2}$$ from periphery of column/capital/drop panel
C. At the drop panel of slab
D. At the periphery of column
A. depends on as, only
B. depends on aCbC only
C. depends on both crst and acbc
D. is independant of both ast and acbc where d is the effective depth, ast is per-missible stress in steel in tension and ocbc is permissible stress in concrete in bending compression.
The diameter of ties in a column should be
A. More than or equal to one fourth of diameter of main bar
B. More than or equal to 5 mm
C. More than 5 mm but less than one-fourth of diameter of main bar
D. More than 5 mm and also more than one-fourth of diameter of main bar
Option C is correct
Reason:
- Interior columns are surrounded by soil on all sides, giving better confinement and support.
- Exterior columns, being on the edge, have less surrounding soil, so they often settle more under the same load.
Reason???