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.