31 Dec 93
Figure A-12. Offset beams model
Guidance for performing a NISA is contained in
these types of calculations can also be performed by
ETL 1110-2-324. ETL 1110-2-324 requires a NISA
hand, although this can become very tedious due to
to be performed on new types of massive concrete
the volume of data available.
structures, structures which have exhibited unsatisfac-
7-5. Nonlinear, incremental structural
tory past performance, and when cost savings can be
analysis (NISA). A NISA is a finite element analy-
achieved through the performance of a NISA. For
the design of a U-frame lock the major objective for
sis which models the construction sequence of a
performing a NISA would be to achieve savings
concrete structure from the time when its first lift is
through more cost-effective construction procedures
placed up through when service loads are applied.
and concrete mixtures.
Within that time frame an analysis provides results
which consider the changes in concrete temperature
7-6. Seismic analysis.
due to heat of hydration and to ambient conditions,
the placement and removal of forms, the aging modu-
a. Guidance. ER 1110-2-1806 mandates seis-
mic design considerations for all Corps of Engineers
defined as a function of time, and the structure is
civil works projects and provides general guidance
incrementally constructed in the finite element model,
and direction for seismic design and evaluation.
simulating actual construction of the monolith.