An Experimental and Numerical Study on the Bearing Capacity of Circular and Ring Footings on Rehabilitated Sand Slopes with Geogrid

Document Type: Regular Paper

Authors

Department of Civil and Environmental Engineering, Shiraz University, Shiraz

Abstract

This paper presents the results of a series of small-scale model tests and numerical analyses conducted on circular and ring model footings located near geogrid reinforced sand slopes. Layers of geogrid were applied as reinforcement. For numerical analyses Finite Element Method (FEM) was used. The effects of reinforcement depth, size, number of layers, and the horizontal distance between reinforcement and the slope surface were experimentally inspected. Moreover, the effects of other parameters such as slope angle, the distance of the footing from the slope crest (for circular footings) and the ratio of inner to outer diameters (for ring fittings) were also  numerically inspected. The results of numerical analyses were compared with the laboratory test results and found to be in fair agreement. Optimum bearing capacity values were found for some studied parameters. The results indicate that if the reinforcement layers are implemented correctly, the bearing capacity of circular and ring footings over slopes would significantly increase.

Keywords

Main Subjects


[1] Binquet, J., Lee, K.L., (1975). Bearing capacity tests on reinforced earth slabs. Journal of Geotechnical Engineering, 121 (12), 1241-1255.

[2] Guido, V.A., Biesiadecki, G.L., Sullivan, M.J. (1985). Bearing capacity of geotextile reinforced foundation. Proceedings of the 11th International Conference on Soil Mechanics and Foundation of Engineers, San Francisco, CA, 1777–1780.

[3] Boushehrian, J. H., Hataf, N., (2003). Experimental and numerical investigation of the bearing capacity of model circular and ring footings on reinforced sand. Geotextiles and Geomembranes, 21, 241-256.

[4] Lee, K. M., Manjunath, V. R., (2000). Experimental and numerical studies of geosynthetic-reinforced sand slopes loaded with a footing. Canadian Geotechnical Journal, 37, 828–842.

[5] Yoo, C., (2001). Laboratory investigation of bearing capacity behavior of strip footing on geogrid-reinforced sand slope. Geotextiles and Geomembranes, 19, 279–298.

[6] Alamshahi, S., Hataf, N., (2009). Bearing capacity of strip footings on sand slopes reinforced with geogrid and grid-anchor. Geotextiles and Geomembranes, 27, 217-226.

[7] Mehrjardi, G. T., Ghanbari, A., Mehdizadeh, H. (2016). Experimental study on the behaviour of geogrid-reinforced slopes with respect to aggregate size. Geotextiles and Geomembranes, 44(6), 862-871.

[8] Hataf, N., Razavi, M. R., (2003). Behavior of ring footing on sand. Iranian Journal of Science and Technology, Transaction B, 27, 47–56.

[9] Mansur, C. L., Kaufman. J. M., (1956). Pile Tests, Low-Sill Structure, Old River, Louisiana. Journal of Soil Mechanics and Foundation Division, ASCE, 82(SM5), 1-33.

[10] Omar, M.T., Das, B. M., Puri, V. K., Yen, S.C., (1993). Ultimate bearing capacity of shallow foundations on sand with geogrid reinforcement. Canadian Geotechnical Journal, 30, 545–549.

[11] Adams, M.T., Collin, J.G., (1997). Large model spread footing load tests on geosynthetic reinforced soil foundation. Journal of Geotechnical Engineering, 123 (1), 66-72.

[12] Akinmusuru, J.O., Akinboladeh, J.A., 1981. Stability of loaded footings on reinforced soil. Journal of Geotechnical Engineering, 107 (6), 819-827.

[13] Das, B.M., Shin, E.C., Omar, M.T., (1994). The bearing capacity of surface strip foundations on geogrid-reinforced sand and clay - a comparative study. Geotechnical and Geological Engineering, 12 (1), 1–14.

[14] El Sawwaf, M. A., (2007). Behavior of strip footing on geogrid-reinforced sand over a soft clay slope. Geotextiles and Geomembranes, 25 (1), 50-60.

[15] Wang, J., Liu, F. Y., Wang, P., Cai, Y. Q. (2016). Particle size effects on coarse soil-geogrid interface response in cyclic and post-cyclic direct shear tests. Geotextiles and Geomembranes, 44(6), 854-861.

[16] Srilatha, N., Latha, G. M., Puttappa, C. (2013). Effect of frequency on seismic response of reinforced soil slopes in shaking table tests. Geotextiles and Geomembranes, 36, 27-32.