Journal Published Online: 01 July 2012
Volume 35, Issue 4

Field Test of Circular Footings on Reinforced Granular Fill Layer Overlying a Clay Bed



The ultimate bearing capacity and settlement of a circular shallow rigid plate on compacted granular fill layer with and without geogrid reinforcement overlying on natural clay deposit exhibiting low bearing capacity and large settlement have been investigated. A total of 15 field tests were carried out using a circular model rigid plate with a diameter of 0.90 m. This study has been initially directed to evaluate the beneficial effects of the compacted granular fill layer on natural clay deposit for the shallow rigid plate performance. Then, the reinforcing effect of the top granular fill layer with horizontal layers of welded geogrid reinforcement on the bearing capacity and settlement has been studied. Parameters of the testing program include granular fill thickness, depth of first reinforcement, vertical spacing of reinforcement layers, and number of reinforcement layers. Bearing capacity ratio (BCR) and percentage reduction in settlement (PRS) were defined to evaluate improvement performance. Based on the test results, the effect of the granular fill and welded geogrid reinforcement on the bearing capacity and settlement are discussed. The results indicate that the use of granular fill layers over natural clay soils has considerable effects on the bearing capacity and settlement characteristics. The construction of granular fill layer with welded geogrid reinforcement over clay deposit helps in redistributing the applied load to a wider area. It has been observed that the use of welded geogrid reinforcement in granular fill layer provides additional improvement of bearing capacity and provides reduction in settlement of the rigid plate up to 80 and 60 %, respectively.

Author Information

Laman, Mustafa
Civil Engineering Dept., Adana Science and Technology Univ., Adana, TR
Yildiz, Abdulazim
Civil Engineering Dept., Cukurova Univ., Balcali/Adana, TR
Ornek, Murat
Civil Engineering Dept., Mustafa Kemal Univ., Iskenderun/Hatay, TR
Demir, Ahmet
Civil Engineering Dept., Korkut Ata Univ., Osmaniye, TR
Pages: 11
Price: $25.00
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Stock #: GTJ103512
ISSN: 0149-6115
DOI: 10.1520/GTJ103512