newmark is an R package for uncertainty analysis in dynamic site and slope response. The fundamental period of a layered soil column, which describes its free, undamped horizontal shear vibration on rigid rock, is approximated by the first Rayleigh iteration in layered form and by a finite element eigenvalue problem. Uniform hazard spectra are evaluated from seismic hazard curves, which give the mean annual frequency with which a ground-motion intensity level is exceeded at a site. The site-response model transforms spectral acceleration at a reference condition into spectral acceleration at a target site condition described by VS30, through a random amplification factor that is lognormal at fixed period, velocities and reference peak ground acceleration. Permanent seismic displacement measures the accumulated movement of a sliding mass during an earthquake. For fixed model inputs, rigid-block and flexible-block regressions represent the positive displacement by a lognormal distribution, and at a fixed yield coefficient an ensemble pools the realizations of its models with normalized weights. The yield coefficient kmax for an admissible displacement Da is the infimum of the positive yield coefficients at which the probability that the projected, non-increasing displacement curve exceeds Da is at most a target exceedance probability. A project stores soil-property summaries, seismic displacement realizations and their summaries, and yield coefficients associated with admissible displacements in the tables ShearTable, DnDraws, DnTable and kmaxTable.
The reference, Functions and data, groups the functions by the same families and lists the data sets.
The library and the newmark command are installed together from the repository root with the product installer.