ESTIMATION OF SETTLEMENT USING STATIC CONE PENETRATION TEST DATA

Abstract

The static cone penetration test is widely used in Europe. This test is also becoming popular in India. IS :8009 (Part I)-1976 also recommends the use of static cone penetration test data for computation of settlement of foundation on sands. Currently, the methods proposed by De-Beer and Marten (1965) and Schmertmann (1978) for estimation of settlement of footings on sand using static cone penetration test data are widely used. In the present exercise a computer program has been developed for computation of settlement using these two methods. Using the computer program, some typical assumed data have been analysed to examine the effect of the following on the settlement of foundation : (0 Depth of foundation (ii) Shape and size of foundation (iii) Stiffness of soil with depth (iv) Angle of shearing resistance (v) Position of water table The analysis show that : (i) The load-settlement curve predicted by the Schmertmann method is similar in form to the load-settlement plot obtained from the plate load tests for a footing resting on sand, while the De-Beer-Marten method resembles e - pcurve obtained in consolidation test. (ii) The settlement obtained from the De-Beer and Marten method is higher for all the widths of foundation than that of the (i) Schmertmann method. (iii) The observed cone penetration values should he moderated to take into account the effect of water table position and these moderated values should be used for settlement computation in the De-Beer-Marten method and the Schmertman method. The procedure of moderating these values is discussed in this dissertation