| Scrap tires possess several advantageous properties which make them preferable to other materials as fills for embankment construction. Such properties include lightweight (the dry unit weight is 1/3 that of soils), high hydraulic conductivity (up to 23.5 cm/s) and low thermal conductivity. These properties result in low lateral pressures on the abutment wall and indirectly in reduced design and construction costs. The low thermal conductivity helps to prevent failure of the subgrade due to frost penetration.; However scrap tires possess high compressibility, a property that leads to settlement of the fill and consequent failure of the embankment. Other undesirable attributes of scrap tire embankments are susceptibility to internal heating and leaching of substances into surrounding water.; An efficient means of controlling such undesirable attributes in the field is by comparing them with those simulated from a model embankment developed by using Bayesian influence diagrams. In this work, the essential responses simulated by using analyticaRTM software program are the temperature, lateral pressure, settlements and leachate characteristics. The most critical embankment characteristics, based on the maximum probability densities, are the settlement and horizontal pressures which are considerably low at 0.428 and 0.0034 respectively. Limits for leachate concentrations were also obtained for the model embankment based on ASTM D 6270 (1998) standards. |
