Geotechnical Engineering

DHARM

420 GEOTECHNICAL ENGINEERING

3. Corrections to the computed settlement values will be necessary for the construction or loading
   period and for the occurrence of lateral yielding or strain; the time for assessing the time-rate of
   settlement is customarily reckoned from the middle of the loading period.


4. Rigidity of the structure and horizontal drainage are further factors affecting the settlement.


5. The accuracy of computed settlements is dependent upon the degree to which the inherent as-
   sumptions in the analysis are valid in a given field situation. Certain authorities specify permis-
   sible values for different kinds of structures and foundations, both in respect of total settlement
   and of differential settlement.


6. Certain remedial measures such as preconsolidation of the site and soil stabilization are possi-
   ble for guarding against the occurrence of harmful settlements.


7. Settlement records are recommended to be maintained after the completion of a structure as
   these serve as a useful indication with regard to the accuracy of the method of analysis.


8. Contact pressure is the actual pressure transmitted from the foundation to the soil; it is uniform
   only for a perfectly flexible structure irrespective of the type of soil. The contact pressure distri-
   bution for a rigid structure is dependent on the nature of the soil.


9. The Terzaghi active zone in a stressed soil mass is the zone within the 0.20q-isobar or pressure
   bulb; 80% of the settlement occurs due to the stress increase in this zone; the depth to which this
   isobar extends (≈ 1.5B) gives an idea of the depth to which exploratory borings should be made.

REFERENCES

1. Alam Singh and B.C. Punmia: Soil Mechanics and Foundations, Standard Book House, Nai Sarak,
   Delhi-6, 1971.


2. M. Bozozuk: Soil shrinkage damages shallow foundations at Ottawa, Eng. Journal, Canadian
   Society of Civil Engineers, 1962.


3. P.L. Capper, W.F. Cassie, and J.D. Geddes: Problems in Engineering Soils, S.I. Edition, E & F.N.
   Spon Ltd., London, 1971.


4. E. De Beer and A. Martens: Method of computation of an upper limit for the influence of the
   heterogeneity of sand layers in the settlement of bridges, Proceedings, 4th International Confer-
   ence SMFE, London, 1957.


5. E.N. Fox: The mean elastic settlement of a uniformly loaded area at a depth below the ground
   surface, Proceedings, 2nd International Conference, SMFE, Rotterdam, 1948.


6. G.G. Gilboy: Soil Mechanics Research, Transactions, ASCE, 1933.


7. J.P. Gould: The effect of radial flow in settlement analysis, S.M. Thesis, Massachusetts Institute
   of Technology, Cambridge, Mass., U.S.A., 1946. (Unpublished).


8. IS: 1904-1978: Code of Practice for Structural Safety of Buildings: Shallow Foundations, Second
   revision, ISI, New Delhi, 1978.


9. A.R. Jumikis: Soil Mechanics, D. Van Nostrand Co., Princeton, NJ, U.S.A., 1962.


10. A.C. Meigh and I.K. Nixon: Comparison of in-situ tests for granular soils, Proceedings, 5th Inter-
    national Conference SMFE, Paris, 1961.


11. G.G. Meyerhof: Penetration Tests and bearing capacity of Cohesionless soils, Proceedings, ASCE,


12. 
    


13. D.E. Polshin and R.A. Tokar; Maximum Allowable Differential Settlement of Structures, Proceed-
    ings, 4th International Conference, SMFE, London, 1957.