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SEISMIC DESIGN
ENGINEERING
seismic DESIGN:
SEI is the AE or record for seismic design projects in the central
continental U.S., the offshore Pacific coastal, and the western India active
seismic regions. We usually design to exceed most building code
requirements. We are familiar with the building code source documents,
The National Earthquake Hazard Reduction Program (NEHRP) Recommended
Provisions for Seismic Regulations for New Buildings and Other Structures,
as well as building codes from The Building Officials and Code
Administrators (BOCA) and The Uniform Building Code (UBC).
The NEHRP Provisions use as a basic safety design objective, a seismic event
that nominally has a 2% chance of exceedance in a 50 year period (2%/50 yr),
rather than what most code requirements are based upon, a 10%/50 yr seismic
event. The 10%/50 yr earthquake has a recurrence interval of 475 years
whereas a much stronger 2%/50 yr earthquake would occur, on average, once
every 2,500 years.
When performing a seismic design for new construction or to retrofit an
existing structure, our analysis and design procedures take into
consideration; site characteristics from geotechnical investigations, type
of structural system, the structure’s fundamental period, the design
earthquake’s spectral response at the site, and all other factors that are
necessary to determine accurate structural solutions.
Our seismic design procedures includes the following:
1.
SEI produces computer simulation models of the structures that allow
different designs for the addition of building structural reinforcement to
be analyzed in detail for accurate cost comparison.
2.
SEI performs life cycle cost analysis for the various proposed
building reinforcement solutions.
3.
SEI prepares preliminary engineering reports to support funding
applications and to justify recommended building modifications.
4.
SEI performs Mechanical HVAC design for seismic event damage
resistance.
5. SEI performs Lighting Fixture support design for seismic event damage
resistance.
6.
SEI performs Electrical equipment anchorage for seismic event damage
resistance.
7.
SEI performs elevator supplemental design for seismic event equipment
damage resistance.
8.
SEI performs furniture, fixtures, and equipment (FFE) seismic
movement resistance design.
9.
SEI performs non-structural systems modification design to resist
seismic event damage.
10.
SEI performs non-structural masonry reinforcement design to resist
seismic event damage resistance.
11. SEI performs design of bracing to support non-structural building
portions such as masonry parapets in order to resist seismic event.
12.
SEI performs structural protection design to reduce damage to
essential equipment that will be needed for Immediate Occupancy (IO) after a
seismic event.
13.
SEI performs mechanical piping support design to resist movement
during seismic events.
14. SEI performs non-structural heavy door movement shock absorber design
and movement limitation design to minimize seismic event caused movement
that might injure of kill personnel.
Seismic DESIGN
PROJECTS: SEI is the seismic design AE of record for the following
projects:
1.
National Imagery and Mapping Agency - St. Louis Air Force Station -
Existing Seven Level Building 36 structural reinforcement for seismic
resistance. $8,100,000.00 - current 2001 project 100% design complete, not
yet constructed.
Mr. John L.Elam, P.E., performed the seismic
evaluation and design on this project. Dr. Khaldoun Fahoum, Ph.D., P.E., Dr.
Sanjeev Kumar, Ph.D., P.E., and Mr. M. Mike Alizadeh, P.E. performed the
seismic design engineering for this project. Gerald Spencer, P.E., was the
project manager and also the mechanical and electrical designer for seismic
resistant systems for the mechanical and electrical systems. Mr. Carl
Talbot, AIA, Mr. Jim Dunaway, AIA and Mr. W. Paul Jones, AIA were the
designers for the non-structural building items.
SEI designed strucural reinforcement for an
existing six level concrete frame structure that was constructed in 1916.
This project designed reinforcement to withstand seismic forces in
accordance with FEMA and NEHRP guidelines. The majority of this project is a
large classified SCIF. SEI designed reinforcement provisions and up-grade
to elevator equipment in order for the one elevcator to be operable
immediately after maximum design design seismic event to be used for
personnel rescue and for classified data evacuation. SEI designed
remainder of structure for life protection only. SEI performed extensive
destructive geotechnical investigation, testing, and reports.
SEI performed the preliminary design for
four optional solutions to determine the most effective life cycle cost
effective solution for this project. SEI also performed the design of the
seismic reinforcing of the mechanical, electrical, and other non-structural
parts of the building.
Geotechnology, Inc. was sub-contracted to
perform a seismic evaluation of Buildings 36, Sections A, B, and C. The
scope of work included subsurface exploration and development of a site
specific response spectra for three levels of seismic activity.
Strong-motion accelerographs, whose data are
used to derive the response spectra, have only recently been installed in
the central United States. Since their installation no large earthquakes
have occurred, so that the existing strong-motion records for the central
U.S. are inadequate for the task. However, much has been learned during the
past 15 years about ground motion scaling, and various relations have been
developed for prediction response spectra based on empirically based
stochastic ground motion models. One such model has recently been developed
by Atkinson and Boore (1995) for ground motions from North American
earthquakes. The predictive relations developed by Atkinson and Boore are
based on the data from southeastern Canada and the northeastern United
States. This model is the current USGS standard for hazard analysis.
This model, coupled with a model developed by
Robert B. Herrman in association with St. Louis University and the
University of Memphis, enabled Geotechnology engineers to accomplish their
desired task. Since the project required consideration of earthquakes
located at any point in the New Madrid Seismic Zone, ground motions were
computed for three different distances from St. Louis: 200km, corresponding
to an earthquake near Cairo, IL or Charleston, MO; 250 km, corresponding to
an earthquake near New Madrid, MO; and 350 km, corresponding to an
earthquake near Marked Tree, AR, the southern limit of present
microearthquake activity. A total of 75 time series were generated for the
models used. The peak values of ground acceleration, ground velocity, and
pseudo-velocity were obtained by averaging all realizations. Geotechnology,
Inc. has the capability to develop site specific response spectra using the
current state-of-the art procedure and data from the New Madrid Seismic
Zone.
This project was designed toFEMA Publication
273 NEHRP GUIDELINES FOR SEISMIC REHABILITATION OF BUILDINGS, the 1999 BOCA
National Building Code, American Society of Civil Engineers (ASCE)
publication 7. This area was previously defined as a seismic zone 3 by the
UBC.
This project design is complete and the
construction is awaiting construction funding.
2.
The U. S. Consulate Modifications - Mumbai (Bombay), India
3.
Lido Hotel, Beijing, China
4.
Temporary VA Hospital, Los Angeles, CA
5.
Chilean Naval Hospital, Punta Arenas, Chile
6.
Computer Room, Port Huene AFB, CA
7.
Plutonium Production Laboratory, Atomic Energy Commission, Rocky
Flats, CO
8.
Offshore oil crew accommodations structure, Santa Barbara, CA
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