An Experimental Study on Geogrid with Geotextile Effects Aimed to Improve Clayey Soil

Authors

1 Faculty of Civil Engineering, Shahid Rajaee, Teacheer Training Universirty, Tehran, Iran

2 Department of Civil Engineering, School of Engineering, University of Minho, Campus de Azure'm, Guimaraes, Portugal

3 Department of Civil Engineering, Aliabad Katoul Branch, Islamic Azad University, Aliabad Katoul, Iran

4 Department of Civil Engineering, Roudehen branch, Islamic Azad University, Roudehen, Iran

Abstract

The increase of shear strength in soil, reinforced with the geogrid (alternate reinforcer), is resulted from an increase of modulus of soil hardness, and also from the tensile strength of reinnforcer. The shear strength of contact surface in soil appears due to both the friction strength against the contact surface, and the passive strength formed in front of the elements of the geogrid system. In the clay reinforced with a geogrid, the resistance of the contact surface is low; therefore, contact surface rupture occurs before the tensile strength reaches the ultimate limit. Also, the geogrid is almost ineffective in limiting particles movement and creating passive resistance in clay, due to a big difference in the sizes of geogrid opening (a perture) comparing to clay grains. In this research, we tried to examine the effect of geotextile layers around the geogrid aimed to improve the soil-geogrid interaction in different drainage conditions by means of triaxle (UU) and (CD) trials on a large scale. Experiments were carried out, based on non-reinforced samples, geogrid-reinforced samples and geocomposite reinforced samples. The results of the experiments showed that the geotextile layers around the geogrid in the clay reinforcements not only effectively improved the interaction of contact surface, where the stresses are concentrated on the geogrid, but enhanced the shear strength parameters, the consolidation and drainage processes, as well. Radiographic results taken from fractal samples indicated that the rupture plate gets a reflection state in the reinforcing elements at the location of geocomposite configurations only, relative to the reinforcing elements. Meanwhile, the geogrid layers did not have any impact on the changes of rupture surface situation.

Keywords


1. Stark, T. D., Williamson, T. A., and Eid, H. T., “HDPE Geomembrane/Geotextile Interface Shear Strength”, Journal of Geotechnical Engineering, Vol. 122, No. 3, (1996), 197–203.
2. Hebeler, G. L., Frost, J. D., and Myers, A. T., “Quantifying hook and loop interaction in textured geomembrane–geotextile systems”, Geotextiles and Geomembranes, Vol. 23, No. 1, (2005), 77–105.
3. Gilbert, R. B., Fernandez, F., and Horsfield, D. W., “Shear Strength of Reinforced Geosynthetic Clay Liner”, Journal of Geotechnical Engineering, Vol. 122, No. 4, (1996), 259–266.
4. Sharma, J. S., Fleming, I. R., and Jogi, M. B., “Measurement of unsaturated soil – geomembrane interface shear-strength parameters”, Canadian Geotechnical Journal, Vol. 44, No. 1, (2007), 78–88.
5. Indraratna, B., Khabbaz, H., Salim, w., Christie, D., “Geotechnical properties of ballast and the role of geosynthetics in rail track stabilisation”, Journal of Ground Improvement, Vol. 10, No. 3, (2006), 91–101.
6. Indraratna, B., Shahin, M. A., and Salim, W., “Stabilisation of granular media and formation soil using geosynthetics with special reference to railway engineering”, Journal of Ground Improvement, Vol. 11, No. 1, (2007), 27–43.
7. Wichtmann, T., Niemunis, A., and Triantafyllidis, T., “Strain accumulation in sand due to cyclic loading: drained triaxial tests”, Soil Dynamics and Earthquake Engineering, Vol. 25, No. 12, (2005), 967–979.
8. Chen, X., Zhang, J., and Li, Z., “Shear behaviour of a geogrid-reinforced coarse-grained soil based on large-scale triaxial tests”, Geotextiles and Geomembranes, Vol. 42, No. 4, (2014), 312–328.
9. Nandanwar, M. R. and Chen, Y., “Simulations of triaxial compression test for sandy loam soil using PFC3D”, In ASABE Annual International Meeting, American Society of 692 M. A. Arjomand et al. / IJE TRANSACTIONS B: Applications Vol. 32, No. 5, (May 2019) 685-692Agricultural and Biological Engineers, (2014), 1–11.
10. Weggel, J. R. and Ward, N. D., “A model for filter cake formation on geotextiles: Theory”, Geotextiles and Geomembranes, Vol. 31, (2012), 51–61.
11. Noorzad, R., and Mirmoradi, S. H., “Laboratory evaluation of the behavior of a geotextile reinforced clay”, Geotextiles and Geomembranes, Vol. 28, No. 4, (2010), 386–392.
12. Liu, C.N., Ho, Y.H., and Huang, J.W., “Large scale direct shear tests of soil/PET-yarn geogrid interfaces”, Geotextiles and Geomembranes, Vol. 27, No. 1, (2009), 19–30.
13. Pincus, H. et al., “Bearing Capacity of Strip Foundation on Geogrid - Reinforced Clay”, Geotechnical Testing Journal, Vol. 16, No. 4, (1993), 534-541.
14. Indraratna, B., Hussaini, S.K.K., and Vinod, J.S., “The lateral displacement response of geogrid-reinforced ballast under cyclic loading”, Geotextiles and Geomembranes, Vol. 39, (2013), 20–29.
15. Sitharam, T.G., and Hegde, A., “Design and construction of geocell foundation to support the embankment on settled red mud”, Geotextiles and Geomembranes, Vol. 41, (2013), 55–63.