Dynamic Properties Of Municipal Solid Waste Landfills From Surface Wave Tests

The seismic stability of municipal solid waste (MSW) landfills is often a significant consideration in landfill<br>design. However, until recently, the dynamic properties of the waste material itself, which govern the seismic<br>response of MSW landfills, have often been approximated or assumed. Tests to determine the dynamic properties<br>of the material directly have been limited. Measurements of seismic surface waves were used to determine the<br>dynamic properties of MSW, which are the initial tangent shear modulus and low-strain hysteretic damping ratio.<br>Surface wave tests were performed at three MSW landfills to determine their shear modulus and damping ratio<br>profiles. Surface wave tests are ideal for measuring the near-surface shear modulus and damping profiles of MSW<br>landflls because the tests are non-invasive, an advantage for testing environmentally sensitive waste material.<br>Factors which influence the dynamic properties of waste including density, confinement, age, and placement<br>techniques are used to interpret the measured shear modulus and damping ratio profiles.