遮水シートの変形強度特性に関する実験的考察

引張り強度の温度特性および応力緩和特性の評価

抄録

Laboratory examinations and numerical analyses were undertaken to clarify the deformation and strength behaviors of water proof sheet, applied at a seepage control structure in an offshore waste disposal site. Water proof sheet, used in this study, is made of Polyvinyl Chloride (PVC), which is mainly used in an offshore waste disposal site. Tensile strength measured on several temperature conditions decreased linearly with the increase of temperature. Degree of stress relaxation of PVC sheet was shown to be constant irrespective of the magnitude of strain, and we proposed the equation about stress relaxation behavior by five-element viscoelastic model. Relationship between tensile stress and strain was evaluated on different strain rate conditions. As the result, tensile stress became larger with the increase of strain rate in the range of small strain, however, in the range of large strain, gradients of stress-strain curves became same for all strain rate conditions.
Creep behavior and the puncture strength using backfilling stone are now under examination, and we will construct a comprehensive model, including those time-dependent deformation and strength properties of PVC sheet.