Basis of Design - Architectural

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25 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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Basis of Design
-

Architectural

Scope of Work

The present construction phase is for Structural Repairs to remove center columns and replace
with new roof supporting girder for Hangar 1067.

Concept

The present structural design submittal results from collaborating with the steel fabricators,
Davison Iron, working through iterative value engineering design alternatives to achieve
the present lighter girder design.

The price of steel has esca
lated. The 2008 July issue of California Construction reported Baosteel,
the largest Chinese steelmaker has agreed to a 65% increase in price of iron ore. There is a lack of
sufficient stocks of iron pellets and coke for the steel mills. The Producer Price

Index for inputs to
construction industries rose a cumulative 30.2% in July 2008, compared to 14.5% for the CPI from
December 2003 to January 2008.

The 100% structural design reduces the amount of steel with a single box girder utilizing standard
and eco
nomic structural components, a standard WF
-
18” at top and bottom flanges of the girder,
and an economic ½”
-
plate x 8’ web for the 2 sides. The new girder extends to the exterior, across
the service road, by 80
-
feet.

Section 1607.11.2 of 2006
-
IBC permits

reducing the roof live loads

The sequence of erection involves welding plates to the existing center columns near the ground
to enable jacking up 3 center columns (west to east) to compensate for the anticipated deflection
of the new girder. Once the new

girder is installed, the deflected girder will return to pre
-
existing
vertical elevations. The anticipated deflection for each of the 3 columns, from west to east, are
5.268 inches, 3.398 inches, and 1.62 inches respectively.

Note: Structural calculatio
ns for Hangar 1067 are based on calculations previously
prepared for Hangar 1068, per agreement with Beale Air Force Base.

Soils Report

The new foundation complies with the recommendations of the April 4, 2008 Soils Report by
Stevens, Ferrone & Bailey. G
eotechnical Engineer Kenneth Ferrone’s reports in his letter, which
reviewed the foundation design as in compliance with the recommen
dations of the Soils Report.

Building Parameters

_Parameters which describe Hangar 1067 are as follows:

Gross Project A
rea: 21,600 SF

Building Height: 38 Feet, 1 Story

Type of Occupancy: S1 (Moderate Hazard)

Type of Construction: II
-
B

Allowable Height;: Unlimited

Existing Site Parameters:

Distance of Hangar 1067 to Road: 34’
-
0” Distance of Hangar to
Center of Road 69

-
0” Distance between Hangars 1067 & 1068:
28”
-
3” Distance between Hangars 1067 & 1045 19’
-
3”

Fire Separation

Since the distance between Hangars 1067 and 1068 to the north is less than 40 feet but greater
than 25 feet, and both hangars have approved fire

suppression systems, no fire separation wall is
required between them per L 98
-
8, Section A1.1.4.1. However, since the distance between Hangar
1067 and Hangar 1045 to the south is less than 25 feet, it will be necessary to provide a 1
-
hour fire
separation

wall at the south end of Hangar 1067. It will also be necessary to provide a 1
-
hour fire
separation wall at the north end of Hangar 1045 and an upgraded fire suppression system as part of
future work per ETL 98
-
8, Section A1.1.4.1.

One
-
hour fire separati
on is achieved with wall construction consisting of 6” x 16GA. (50 ksi) metal
studs at 16”o.c. with 1
-
layer 5/8” Type ‘X’ gypsum wallboard on each side per Item No. 13
-
1.3
(similar), Table 720.1(2), IBC 2009 edition. The one
-
hour wall construction shall ex
tend from the
foundation to the underside of the non
-
combustible roof sheathing. Weatherproofing shall be
achieved by the re
-
attachment of the exterior metal siding.


Basis of Design
-

Electrical

Existing Electrical Distribution System

The scope of work

is to remove the 3 center columns and free standing office enclosure to
accommodate 2 global hawk aircrafts. Hangar 1067 power is served by a 800A,

Electrical Demolition and New work

All the column mounted electrical receptacles will be disconnected an
d savaged for relocation.
Associated conduit and wires will be removed all the way back to the power panels. Four new 100A
receptacles with a disconnect switch and 150A receptacles with an enclosed contactor shall be
installed. New conduit and wire will be

running to the new locations. A new 400A, 480V, 3 phase
panel “HSN” fed from panel “DHS” will feed the new 100A receptacles. The 150A receptacles will
feed from panel “DHS”.

Existing 277V HPS fixtures shall be controlled by a new relay panel and time cl
ock. The control
system shall consist of a master control panel with 3 sub
-
panels. Each sub
-
panel will be located on
each wall and control two rows of lights. An override switch will control the master controller.

Mechanical HVAC will be installed at th
e back of the hangar. HVAC power with the
disconnect switch will be provided. Outdoor type with ground fault interrupter receptacles will
be installed per each HVAC unit.

Power Conditioning

The Air Force personnel expressed some concern on the power q
uality; however, testing and
monitoring data were not presented. We recommended performing a monitoring test at the
incoming service line to determine what type of power issues such as spike, transients, harmonics,
sags and swells. Power conditioning sha
ll be designed according the collected information.
Proposed power conditioner location is shown on the floor plan. Further investigation shall be
performed as an added scope. Ball park cost estimate for adding power conditioner is about
$10,000.


Basis
of Design
-

HVAC

Scope of Work

The project scope of work is to provide 5 tons of on
-
demand cooling to each wing of a parked
Global Hawk aircraft in the north bay of Hangar 1067.

Background of Existing HVAC Systems

An existing air conditioner and associ
ated ductwork mounted on top, and serves, the central
office at the existing hangar 1067.

The air conditioner and associated ductwork mounted on top of the existing trailer office will be
removed, along with associated controls and power wiring. The condensate drain piping connected
to the air conditioner will be removed back to the hangar wall

and capped.

Proposed HVAC System for the Hangar 1067 North Bay aircraft wing cooling

The proposed HVAC system for the building will comply with Beale Air Force Base Facilities Design
Standards 2002, Director of Central Intelligence Directive No. 6/9, E
ngineering Technical Letter
(ETL) 01
-
18, Uniform Mechanical Code and ASHRAE Standards. The wing design temperature will
be set at 70 degrees Fahrenheit for summer and winter. The outdoor design temperatures of 102
degrees F Dry Bulb and 70 degrees F Wet Bu
lb during the cooling period and 28 degrees F for the
heating period will be selected. The outdoor design temperatures are based on the ASHRAE
publication SPCDX Climatic Data for Region X using 0.5% for the summer and 0.2% for the winter.

The proposed new

HVAC system includes:

Ground mounted packaged air conditioning unit with housekeeping pad, with fan, refrigerant
cooling coils, low ambient cooling and packaged controls. Two units are proposed, each one to
provide five tons of cooling to each aircraft
wing. The project area is inside the north bay of the
hangar and sheltered from weather. No ventilation air is required to be added to the supply air from
the air conditioner.

HVAC air conditioner controllers shall be provided by the fan coil manufacturer
.

Interior lined supply and return metal duct is proposed to penetrate the hangar exterior wall from the
packaged air conditioner into the hangar space, rise along the wall and traverse the hangar space
below the hangar roof beams to directly above the pa
rked aircraft wings. The metal ducting will be
braced to the wall and roof girders & beams in accordance with SMACNA and applicable structural
and building codes. Flexible heavy duty fabric duct is proposed to drop, return and supply, from the
overhead met
al duct down to the aircraft wings and connect to a fabric duct encapsulating the
aircraft wing from wingtip to aircraft wing landing gear. The duct drops will be positioned so that the
metal connection elbows are minimum one foot from the edge of the airc
raft wings, requiring the
flexible duct to curve near the wing to make the connection to the wing enclosing fabric duct. Supply
flexible duct will drop to the wingtip side of the fabric duct, and return flexible duct will drop the
landing gear side of the
fabric duct. The flexible ducts collars will fasten to the fabric duct collars,
and suspend the top of the wing fabric duct above the wing. The flexible riser duct positions will be
adjusted by cable and pulley. A manually operated winch with brake will be

used to retract back the
cable and attached flexible ductwork end during times the wings are not air conditioned, so that the
flexible duct is suspended in a horizontal position back in the direction of the hangar The fabric
wing
-
enclosing duct is propose
d to be constructed as one 80 inch diameter, 52
-
foot long section,
one to provide cooling to each wing of the aircraft. The fabric duct end at the wing tip side will be
provided with a fabric cap. The fabric duct end at the fuselage side of the wing will b
e provided with
Velcro strips to allow the fabric duct to be wrapped and sealed tight against the wing. When wing air
conditioning is complete, the fabric duct Velcro seals can be unsealed, and the duct can be removed
from the wing and stored in a sheltere
d location. Anti
-
static fabric ductwork for the wing duct is
proposed.


Basis of Design


Plumbing

Plumbing System

Existing Plumbing System

The hangar has no existing plumbing piping.

Proposed Plumbing System

Due to lack of nearby existing sanitary s
ewer for connection, thick reinforced ground concrete
required to remove and replace for trenching and lengthy trench distance to nearest sanitary sewer
if pursued, and non
-
daily/partial day operation of the new wing cooling air conditioners minimizing
con
densate, condensate drainage from the new wing cooling outdoor air conditioners shall be
allowed to drain to ground.