1. 2 3 4 Jacking of Track (3.27) Get track geometry reading before jacking Do no jacking at...
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1. 2 3 4 Jacking of Track (3.27) Get track geometry reading before jacking Do no jacking at crossovers or next to switch locations for x--brace replacement
4 Jacking of Track (3.27) Get track geometry reading before
jacking Do no jacking at crossovers or next to switch locations for
x--brace replacement .instead install x--bracing at a lower
elevation, using a 5/8 thick clip angle attached to the vertical
legs of the top flange angles
Slide 5
5 Jacking of Track Jack one rail at a time, 2 max, for ea
increment Maintain track alignment: install temp guide angles tight
to top flanges under wood ties just outside installation area at
both ends prior to jacking
Slide 6
Jacking of Track Before jacking: disconnect conduits,
air-lines, grease lines, etc., attached to track 6 After
completion: reconnect
Slide 7
Jacking of Track At abutments: Elevated track runs into ballast
area Loosen rails from ties in ballast Disconnect at nearest joint,
if possible 7 Remove spikes/ pandrol clips Keep ballasted ties, in
place Track profile wont change
Slide 8
Contact Rail Safety Working under live C/R: -nail continuous 18
wide strip of plywood to bottom of ties to 6 beyond repair area
prior to start 8 In winter weather: remove the boards after ea
workday to avoid snow accumulation under C/R
Slide 9
Contact Rail Safety GO Work at track level near live C/R : wrap
C/R w rubber mat to 6 beyond repair area 9 Working near C/R w power
off: have light bank & audible alarm connected
Slide 10
Welding (3.16 a c) Not permitted for members or connections
subject to impact or fatigue loading Shop welding otherwise allowed
10 Field welding not permitted except for bldgs (no groove welds)
Stiffeners welded to compr flange & web only not tension flange
Electric arc / lo hydrogen electrodes
Slide 11
Welding (3.16 c e) Per Amer Railway Engrg / MOW/ AISC
Workmanship : AWS 11 All welded joint procedures shall be pre-
qualified per D1.1 sect 4 however. submit weld procedure for
approval on Annex E forms
Slide 12
12 Welding (3.16 c e) All welds: visual inspection All shop
& field fillets: magnetic particle (E709) All shop groove:
ultrasonic (E164) Consultant for field welds: full time; 5 yr exp;
provides weld certification & test reports Take coupons of
existing steel & test (3.27g)
Slide 13
WELDING SYMBOLS Solid flag = a field weld 13
Slide 14
WELDING filet weld required at point of the arrow 14
Slide 15
WELDING 15 Weld on both sides of the joint
Slide 16
WELDING 16 Circle = weld all around
Slide 17
WELDING Quarter inch = length of weld leg Called the weld size
17
Slide 18
18
Slide 19
WELDING actual throat - shortest distance betw weld root &
face of a fillet weld 19 TOE
Slide 20
WELDING 20 effective throat -minimum distance minus any
convexity betw weld root & face of a fillet weld
Slide 21
WELDING 21 root opening: separation at joint root betw the work
pieces
Slide 22
WELDING 22 Triangles not aligned: welds are staggered 2-8 = 2
welds spaced 8 apart
Slide 23
23 WELDING May be easier to weld gusset to column in field vs a
fabricated bolted connection
Slide 24
24 Field Welding Rules-of-thumb : no welds where calculated
stress exceeds 50% of working stress no transverse welds across
tension members no welds where calculated stress exceeds three ksi
unless shored make all welds parallel to stress lines
Slide 25
25 Weldability of Old Steel Cut/drill samples from redundant
parts of existing steel Test mechanically for ductility Test
chemically for carbon content, phosphorus (increased brittleness)
& hi sulfur (porous welds) take from thickest parts of members
(usually exhibit greatest property fluctuation) lo-hydrogen
electrodes & preheating can improve weldability of most base
metal
Slide 26
Weldability OnSite Test Weld deforms w/o fracturing: weldable
26 Weld separates from base metal at junction of weld & base:
base metal subject to hardening (hi carbon content Separation
exhibits a gray granular surface & follows profile of heat
affected zone, appearing as a shallow crater in base metal
Slide 27
Avoid Undercutting 27 Undercut potential: have undercut occur
in new matl Undercut member in tension or subject to fatigue: grind
out/ fill w sound metal/ grind smooth Keep grind marks // to stress
lines or reduce grind profile by finishing w lt press
Slide 28
HAZ 28 Heat Affected Zone: 1/8 - 3/16 width betw molten weld
rod + base metal (1,250 - 2,700F range) In HAZ, changes in
molecular & steel grain structure Cracks ~ dont start in HAZ
but in unsound weld metal nearby & travel into base metal Steel
melts ~ 2,800F 1,333F +: austenitic changes 1,500F: yield ~ 0;
loses magnetic properties 1,200F: max for heat cambering or
straightening 500-600F: max strength, but loss of ductility
Slide 29
29 Quiz #5 How should you deal with repair plate interference w
existing steel? How to deal w gussets hidden under ties? What
deliverables should post design include? How do you keep track
aligned when jacking it?
Slide 30
Steel Erection 30
Slide 31
FRAMING Spandrel (girt) is on perimeter & transmits
exterior wall loads to columns 31
Slide 32
FRAMING 32 Rafters: *closely spaced beams *support roof *run //
to slope Purlins span between Flat roofs: rafters- called
joists
Slide 33
Opening thru a Floor 33
Slide 34
Erection: Column / Footing Prep 34 Use multiple shim plates
with heavy columns
Slide 35
35 Erection: Column / Footing Prep Mark footing w C/Ls in ea
direction Mark ea column base plate w C/Ls Line them up when
setting column LEVELING SHIMS
Slide 36
OSHAGuidelines for a Site-specific Erection Plan Controlling
contractor must provide written notice to steel erector ensuring
that [1926.752(a)]: Concrete ftgs, piers & walls are cured to
level to 36 provide adequate strength to support any forces imposed
during steel erection [1926.752(a)(1)] Anchor bolt repairs,
replacements & mods were done w approval of project Structural
Engineer of Record (SER) [1926.752(a)(2) & 1926.755(b)(1)]
Slide 37
OSHAGuidelines for a Site-specific Erection Plan Controlling
contractor must provide & maintain [1926.752(c)]: Access roads
into & thru site that are adequate for 37 safe delivery &
movement of: derricks, cranes, trucks & other necessary
equipment & matl Hold conferences & site inspections
between erector & controlling contractor & fabricator
before start of steel erection
Slide 38
38 OSHA: Site-specific Erection Plan Components : Sequence of
erection, develop w contractor: *Material deliveries: staging /
storage *Coordination w other trades Crane selection &
placement procedures: *Site preparation/ Path for overhead loads
*Critical lifts, incl rigging supplies/ equipment
40 OSHA: Site-specific Erection Plan Erection activities/
procedures contd: Connections incl Ornamental /misc iron Fall
protection procedures Falling object protection Special procedures
for hazardous non-routine tasks Certification for ea employee
trained for steel erection operations
Slide 41
OSHA: Site-specific Erection Plan Erection activities/
procedures contd: List the qualified & competent persons 41
Describe rescue or emergency response procedures Have plan signed
& dated by the qualified persons responsible for its
preparation & modification
Erection Sequence Work out sequence w fabricator early Make a
tier sequence listing w foreman Lay out steel in sequence to be
installed 43 Mark left side/west side of beam or bottom of a column
to allow iron worker to know correct end position Fabrs Bolt sched-
ea conn: B5A13-B512: #; dia; length; grade; nuts; washers; grip
Mark info from bolt list on ea end/ea piece
Slide 44
Column Lifting 44
Slide 45
Column Lifting 45 Tag line - used to pull pin out of shackles
after weight is off
Slide 46
Second Tier and up Put in stairs & handrails before
starting next tier 46 Easier & safer for workers to get to
upper levels
Slide 47
Life on the 50 th Tier (50-65 pcs/day) 47
Slide 48
Erection Crew (3.24) 48 Lightly drifts holes for drawing
together; not for fair aligning Install 50% bolts min
Slide 49
Bolt- -Up Crew Plumbs frame using turnbuckles Fills all holes w
permanent bolts Reams unfair holes Also for stabilizing frame
49
Slide 50
50 Reaming- rehab work No lubricant needed All holes: 1/16
>specd bolt Can use a regular drill - makes a mess Reamed,
oblong hole: 3/16 max, larger than bolt used (3.27e4) Use next size
drill bit & larger bolt: may slip in smaller bolt Drill
shavings at ironworkers feet: hes been reaming
Slide 51
Reaming- new assemblies All holes: 1/16 > specd bolt No
lubricant needed Ream together 51 1/32max offset between plies of a
new assembly (3.9). same size bolt allowed If hole is larger: must
be re-drilled & next larger dia. bolt used Burrs removed w tool
making 1/16 fillet (3.6)
Slide 52
Holes If more than 3 unfaired holes that require reaming per
connection, get new piece of steel 52 Check holes in new & old
steel to see if they match Catch at beginning of installation vs
taking new piece down
Slide 53
Before installing bolts Ensure proper seating by preparing
surfaces w power grinding tool (3.25c) Washer under element to be
turned: A325 53 Washers on both sides: A490
Slide 54
Bolt Lubrication Prevents thread lock & reduces twisting
force introduced into bolt 54 Stick waxes can be used in field to
lubricate fastener assemblies if soluble lubricant was washed away
due to improper storage
Slide 55
. Bolt w stripped threads A proper fastener assembly will fail
by fracture thru the threads of the bolt outside the nut 55
Slide 56
Bolt Lubrication Black, lubricated bolts & nuts: oily to
touch when delivered & installed 56 Galvanized nuts should be
lubricated w a visible lubricant
Slide 57
Using ASTM A325 or A490 Bolts BOLTED PARTS Slip Critical Joints
Faying surfaces, incl filler plates & finger shims shall be:
free of scale, except for tight mill scale free of coatings in
areas closer than 1 bolt diameter but not less than 1 from edge of
any hole free of coatings in all areas w/i bolt pattern 57
Slide 58
58 Only area local to bolt influences slip behavior Portions
outside striped areas will not influence slip performance of
connection
Slide 59
Faying Surfaces Loose scale or rust must be removed prior to
making connection 59 Removal should be done by blasting or wire
brushing
Slide 60
60 PRE INSTALLATION VERIFICATION Required Testing: 3 min.
complete fastener assemblies of ea diam, length, grade & lot:
check at install site in hydr tension calibrator (Skidmore) (table
II note 3) Verify: pre-tension method develops pre-- tension = or
>1.05 X spec for pretension values (table II note 1). Use
washers as in the work If actual pretension is