VISUAL-Q4M Options

The Quad4m code computes the dynamic site response of a two-dimensional soil using Linear Elastic wave propagation or Equivalent Linear wave propagation with strain dependent dynamic soil properties. For Linear Elastic (LE) dynamic analysis, the Shear Modulus and Damping Ratio are not dependent of the strain, while in the Equivalent Linear analysis (EQ) the value of the Shear Modulus and Damping Ratio are function of the strain calculated in each single element in according to stress functions defined. The resolution is iterative until there are not evident differences in the deformation value between the calculation cycles.

  • Linear Elastic

    The calculations requires only one calculation cycle for the resolution

    It is not necessary to insert stress-functions because there is not variation of the Shear modulus and the Damping Ratio

    The resolution is very fast

  • Equivalent Linear

    The calculations requires more cycles until the strain reach a constant value

    It is possible to perform a combined calculation by inserting stress functions only for some zones or group of zones

    The resolution takes more time

The Quad4m code, during the calculation cycles, computes the maximum strain obtained for each zone and the average value of Damping Ratio into the whole model analyzed (1 Run = 1 Average Value). The Visual-Q4M compares this value with that of the previous analysis by calculating a "Check-Run" control value used to determine the number of maximum iterations necessary to obtain a complete analysis.