Use of tire-derived aggregate in tunnel cut-and-cover

Abstract

Abstract.A case-history is reported in which tire derived aggregate (TDA) was successfully applied to reduce the weight of fill upon a cut-and-cover railway tunnel. Subsequent 3D numerical analyses are used to explore the effect of different assumptions about the constitutive model of the TDA material. Alternative dispositions of TDA around the tunnel section are also examined. Reductions of up to 60% in lining bending moment may be achieved. For the case analyzed the elastic description of the TDA has little influence on tunnel lining loads, although is important for fill settlement estimates.

Use of Tyre-Derived Aggregate as Backfill Material for Wave Barriers to Mitigate Railway-Induced Ground Vibrations

“…Since these models seem more suitable to simulate the behaviour of these materials, this paper studied the influence of the constitutive model of the TDA material on the level of vibration transmission. Other authors, such as Medina et al [ 33 ] have applied these constitutive models in cases of lightweight tunnel backfills, in which this material was used to reduce strains and stresses in the tunnel lining.…”

“…For the nonlinear isotropic model, the following stress–strain relationship was used: where ε is the axial strain (%), σ the axial stress (kPa), and a and b are parameters that need to be adjusted. In this case, the values deduced by Medina et al [ 33 ] were used and are shown in Table 5 . In the case of the linear anisotropic model, the adopted values were also taken from [ 33 ] and are also shown in Table 5 .…”

“…The TDA material is made from used conventional commercial tyres. Table 3 shows its mechanical properties, considering a linear elastic model [ 33 ]. These properties correspond to the gradation of the TDA material shown in Table 4 and were obtained under laboratory conditions.…”

“…Large quantities of tyre-derived material are generated annually worldwide. Recent studies show production of 6.4 and 12.6 kg/resident/year in Europe and the USA, respectively [ 33 ]. Logically, when this material is no longer usable due to deterioration, it becomes a waste and, given the environmental risk involved, many efforts have been made to increase its recycling and/or reuse.…”

“…Its applications in civil engineering are continuously increasing, and its road and railway engineering applications stand out [ 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. In addition, it has been used in easing embankments on soft soils and on tunnels, the latter built with the cut-and-cover system [ 33 ]. However, it has not been specifically used as a material for filled trenches or pile wave barriers as a mitigation measure for rail traffic vibrations.…”