Authors:
Abdul Farhan,Farman Ullah,Fawad Ahmad,Mehr E Munir,DOI NO:
https://doi.org/10.26782/jmcms.2019.06.00044Keywords:
Bearing capacity,plate load test,Abstract
Bearing capacity is the main criteria for designing the foundation of a structure. Several theories and experimental methods have been propounded by many researchers for computing the bearing capacity parameters separately. Traditional bearing capacity theories for determining the ultimate bearing capacity of shallow foundations assume that the bearing stratum is homogenous and infinite. However this is not true in all cases. Layered soils are mostly encountered in practice. It is possible to encounter a rigid layer at shallow depth or the soil may be layered and have different shear strength parameters. In such cases shear pattern gets distorted and bearing capacity becomes dependent on the extent of the rupture surface in weaker or stronger material. The best estimation of bearing capacity on layered soil are possible only, if the pressure-settlement characteristics of the foundation-soil are known for the size of the footing. From the review of literature, it may be noted that the bearing capacity equations proposed for the homogenous soils by Terzaghi (1943) and Meyerhof (1951) are not applicable to layered soils. Hence it is necessary to develop an equation for predicting the bearing capacity of granular layered soils. In present investigation, plate load test have been conducted in a large tank to observe the load settlement behavior of plates of different sizes resting on layered granular soils. Tests were conducted on two layers of soils. Fine gravel layer overlain sand layer were tested using mild steel plates of square shapes. The effect of the placement of layers on the bearing capacity characteristics of footing, has been studied and an equation for predicting the bearing capacity of two layered granular soils is developed based on the plate load test data.Refference:
I.Hanna A. M. Bearing Capacity of Foundations on a Weak Sand Layer Overlaying a Strong Deposit, Canadian Geotechnical Journal, 1982: 392-396.
II.Hanna, A.M., and Meyerhof G.G. (1980), “Design charts for ultimate bearing capacity of foundations on sand overlying soft clay”. Can. Geotech.J, 17(2). 300-303.
III.Meyerhof, G. G. Hanna A. M. Design Charts for Ultimate Bearing Capacity of Foundations on Sand Overlaying Soft Clay. Canadian Geotechnical Journal, 1980, 17: 300-303.
IV.Michalowski, R.L. (1997). An estimate of the influence of soil weight on bearing Capacity using limit analysis. Soils and Foundations, Vol. 37, No.4, pp. 57-64.
V.Meyerhof, G. G. & Hanna, A. M. (1978), ultimate bearing capacity of foundations on layered soils under inclined load. Canadian Geotechnical Journal, vol. 15, n. 4, pp. 565-572.
VI.Srivastava, A.K. (1982), Relevance of small scale model tests for estimating load settlement behavior of footings on sand.” M.Tech dissertation.
VII.Terzaghi, k. and Peck, R. B. (1967) Soil Mechanics in Engineering Practice, 2nd edition John Wiley and Sons Inc, New York, USA.
VIII.Valsangkar A. J, Meyerhof, G. G. Experimental Study of Punching Coefficients and Shape Factor for Two Layered Soils. Canadian Geotechnical Journal, 1979, 16: 802-805.
IX.Varghese P.C., A text Book of Foundation Engineering, Prentice Hall of India Pvt. Ltd., New Delhi, Edition 2005
Abdul Farhan, Farman Ullah, Fawad Ahmad, Mehr E Munir
View
Download