Differential Settlement over a Long Span
Differential Settlement over a Long Span
(OP)
Dear Professional, may I ask what is the differential settlement deflection value with an associated span such as 1/2" over a 40-50 linear-foot span.
Is this derived from calculation fro lab data? Our office derive it from the NAVFAC figure...
I was told that this is also based on building angular distortion chart; if this is the case, then can anyone helping me that why a soil engineer needs to recommend this differential settlement to determine column span?
Kind regards,
Is this derived from calculation fro lab data? Our office derive it from the NAVFAC figure...
I was told that this is also based on building angular distortion chart; if this is the case, then can anyone helping me that why a soil engineer needs to recommend this differential settlement to determine column span?
Kind regards,





RE: Differential Settlement over a Long Span
Hope this help!
RE: Differential Settlement over a Long Span
RE: Differential Settlement over a Long Span
The serviceability limits are (or should be) specified by the different design codes, industry practice or by structural engineers (newly implemented Euro Code leave this portion to different National Annex; North American States and provinces may have their own limits for buildings, bridges, dams, structures, etc.).
Allowable settlements and limiting distortions are reviewed and discussed by Robert Day in Foundation Engineering Handbook Section 7.6. I remember seeing a similar discussion in one of the Das foundation books.
In the original post, the NAVFAC figure and the building distortion chart are used to define the design limits. The calculation for settlement using field or laboratory data is performed to verify that these are within the limits.
It is necessary to determine the potential total and differential settlements or allowable distortion. It is more so when the structural engineers wonder whether he should implement structural solutions (say, strengthen the beam or footings at high load places).
RE: Differential Settlement over a Long Span