ARCHING IN PILED EMBANKMENTS

Model tests and theoretical analysis were done to investigate the arch ing in embankments on soft ground supported by piles with cap beams an d geotextiles. The cap-beam-and-geotextile combination may alleviate t he uneven surface settlements that sometimes occur in embankments supp orted by piles with individual square caps. In the model tests, sand w as placed on simulated cap beams and soft ground. The loads on the cap beams and soft ground were recorded and compared with theoretical ana lysis based on equilibrium of semicylindrical sand arches. In a second series of model tests, a geotextile layer was laid on the cap beams a nd the soft ground prior to placement of sand. Equations and charts we re developed to show the parameters affecting the tension in the geote xtile and to assess the effect of geotextile on load transfer. Theoret ical solution showed reasonable agreement with experimental results fo r cases with no geotextile but only partial agreement for cases with g eotextile. The limitations of the model tests, the factors affecting t he results, and alternative interpretations are discussed.