A bearing capacity calculation method for soil reinforced with a geocell J. O. Avesani Neto 1 , B. S. Bueno 2 and M. M. Futai 3 1 PhD Student, Sa ˜o Carlos School of Engineering, University of Sa ˜o Paulo – EESC/USP, 13566-590 Sa ˜o Carlos, SP, Brazil, Telephone: +55 11-986201152, Telefax: +55 16-33739509, E-mail: avesani.neto@gmail.com 2 Professor, Sa ˜o Carlos School of Engineering, University of Sa ˜o Paulo – EESC/USP, 13566-590 Sa ˜o Carlos, SP, Brazil, Telephone: +55 16-33739501, Telefax: +55 16-33739509, E-mail: bsbueno@sc.usp.br 3 Professor, Engineering School, University of Sao Paulo – EP/USP, 05508-010 Sa ˜o Paulo, SP, Brazil, Telephone: +55 11-30915246, Telefax: +55 11-30915181, E-mail: futai@usp.br Received 25 June 2012, revised 30 November 2012, accepted 9 February 2013 ABSTRACT: Geocell geosynthetics have been used in several areas of geotechnical engineering, such as retaining walls, slope protection against erosion, road bases and channel lining. However, geocell was initially designed to improve soil bearing capacity. Performing works in soft soils is always a challenge to geotechnical engineering and involves risks, such as (global and local) soil failures and large settlements. As reinforcement, geocell satisfactorily increases the bearing capacity of the soil, enabling its use. In this regard, this paper presents a method for predicting the bearing capacity of geocell-reinforced soils, taking into account the soil foundation bearing capacity and the geocell reinforcement mechanisms – the stress dispersion effect and the confinement effect. The proposed method is verified with the results of laboratory experiments by several researchers and compared with other calculation methods. The results show that the calculated bearing capacity obtained by this method give a better fit to the experimental results than other methods. The method also proved to be a good approach for different geocell characteristics (geometry), foundation soil and geocell infill (sand and clay) and loading shape (circular, rectangular and strip). KEYWORDS: Geosynthetics, Soil reinforcement, Soil improvement, Calculation method, Soft soil REFERENCE: Avesani Neto, J. O., Bueno, B. S. & Futai, M. M. (2013). A bearing capacity calculation method for soil reinforced with a geocell. Geosynthetics International, 20, No. 3, 129–142. [http://dx.doi.org/10.1680/gein.13.00007] 1. INTRODUCTION The construction of embankments on soft soils involves numerous difficulties for both designers and contractors. Although there are several conventional techniques that avoid or improve soft soils, such as removing and replacing the soil, piled embankments and consolidation, they are not always feasible because of time, economic or execution issues. Other approaches can be applied in these cases, some with large and expensive structures and others with smart applications of geosynthetics improvement, such as soil reinforcement. These include solutions, such as lightweight fill and planar reinforcement with geogrid and geotextile. In this option, geocell has the same ability as high-performance geogrids and geotextiles to improve the soil bearing capa- city. In fact, geocell has additional advantages because of its form, which makes it far superior to other types of interven- tion regarding reinforced soil performance (Dash et al. 2003, 2004; Zhou and Wen 2008; Madhavi Latha and Somwanshi 2009; Moghaddas Tafreshi and Dawson 2010). Several authors have conducted laboratory and field experiments to show the benefits of using geocell rein- forcement in soil. Bathurst and Jarrett (1988) and Bathurst and Crowe (1992) performed a large-scale model test programme to investigate the load–deformation perform- ance of geocell-reinforced mattress. Rea and Mitchell (1978), Mandal and Gupta (1994), Mhaiskar and Mandal (1996), Krishnaswamy et al. (2000), Dash et al. (2001a), Meneses (2004) and Mengelt et al. (2006) evaluated the influence of geocell pocket size (aspect ratio) in improve- ment. Rajagopal et al. (1999) and Wesseloo et al. (2009) performed triaxial and uniaxial tests in soil samples rein- forced with one-cell and multiple-cell structures to analyse the strength and deformation of the reinforcement for differ- ent numbers of cells. The influence of type, strength and stiffness of the geocell material was studied by Rajagopal et Geosynthetics International, 2013, 20, No. 3 129 1072-6349 # 2013 Thomas Telford Ltd