An Experimental and Numerical Investigation into the Compressibility and Settlement of Sand Mixed with TDA

A series of large scale oedometer experiments were carried out to investigate the settlement of sand reinforced with tire derived aggregates (TDA). The parameters studied were five different amounts of TDAs, three aspect ratios and relative skeletal densities, and seven overburden pressures. The volume compressibility coefficient was calculated against different input parameters, and the constraint condition used enabled Poisson’s ratio to be calculated from an “at-rest” coefficient of earth pressure. The triaxial modulus was calculated indirectly and then adopted in subsequent numerical analyses. Finite element analysis and Monte Carlo simulations were used to investigate the settlement of this mixture and to study how the different parameters affected the settlement mixtures of sand and TDAs. The experimental and numerical results reveal that the amount of TDAs is the major parameter which affects settlement, although the overburden pressure and relative skeletal density are also important. The aspect ratio of the shred has almost no effect on volume compressibility parameters as long as constraint compression condition governs. Two index parameters were defined to discuss the type of shred distribution and how it affects settlement of the mixture.