Experimental and numerical distribution of pressure on the abutment with backfill from tyre bales

This article describes the tests of the pressure distribution on bridge abutment generated by the backfill made of the recycled car tyres compressed in the form of bales with interfaces of medium sands and a buffer layer with tyre shreds. Backfill pressure distribution was measuring continuously over a period of three months using a pressure sensors. Static and dynamic load tests of abutment were conducted and cyclic horizontal displacements of the abutment wall, as a simulation of thermal elongation / shortening of the bridge span were also performed. The results of pressure field measurements were compared with results of numerical analysis performed using the GEO5 program basing on finite element method. Compatibility results of field measurements and numerical analysis was pretty good, and the maximum difference was about 25%. Based on field measurements and numerical analysis, a 2÷4 times reduction of pressure on bridge abutment was found, if the tyre bales had been used, compared to conventional backfilling of medium sand.