1. 2 3 4 Jacking of Track (3.27) Get track geometry reading before jacking Do no jacking at...
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- 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
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- 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
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- Jacking of Track Before jacking: disconnect conduits,
air-lines, grease lines, etc., attached to track 6 After
completion: reconnect
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- 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
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- 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
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- 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
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- 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
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- 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
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- 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)
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- WELDING SYMBOLS Solid flag = a field weld 13
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- WELDING filet weld required at point of the arrow 14
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- WELDING 15 Weld on both sides of the joint
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- WELDING 16 Circle = weld all around
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- WELDING Quarter inch = length of weld leg Called the weld size
17
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- WELDING actual throat - shortest distance betw weld root &
face of a fillet weld 19 TOE
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- WELDING 20 effective throat -minimum distance minus any
convexity betw weld root & face of a fillet weld
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- WELDING 21 root opening: separation at joint root betw the work
pieces
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- WELDING 22 Triangles not aligned: welds are staggered 2-8 = 2
welds spaced 8 apart
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- 23 WELDING May be easier to weld gusset to column in field vs a
fabricated bolted connection
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- 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
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- 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
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- 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
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- 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
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- 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
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- 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?
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- Steel Erection 30
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- FRAMING Spandrel (girt) is on perimeter & transmits
exterior wall loads to columns 31
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- FRAMING 32 Rafters: *closely spaced beams *support roof *run //
to slope Purlins span between Flat roofs: rafters- called
joists
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- Opening thru a Floor 33
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- Erection: Column / Footing Prep 34 Use multiple shim plates
with heavy columns
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- 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
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- 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)]
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- 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
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- 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
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- 39 OSHA: Site-specific Erection Plan Erection activities/
procedures : Stability requiring temporary bracing & guying
Erection bridging terminus point Anchor bolt notifications:
repair/replacement/modifications Column / beam installation incl
joists/ purlins
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- 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
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- 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
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- Erection Sequence (1.13) F1, 1.1, 2 E1, 2 B5A13 B532, 510 B511,
5A6 B512 B513, 514 D18,25,20 D30,43,21 D32,45,21 D24,23,20 42
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- 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
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- Column Lifting 44
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- Column Lifting 45 Tag line - used to pull pin out of shackles
after weight is off
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- Second Tier and up Put in stairs & handrails before
starting next tier 46 Easier & safer for workers to get to
upper levels
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- Life on the 50 th Tier (50-65 pcs/day) 47
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- Erection Crew (3.24) 48 Lightly drifts holes for drawing
together; not for fair aligning Install 50% bolts min
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- Bolt- -Up Crew Plumbs frame using turnbuckles Fills all holes w
permanent bolts Reams unfair holes Also for stabilizing frame
49
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- 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
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- 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)
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- 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
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- 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
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- 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
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- . Bolt w stripped threads A proper fastener assembly will fail
by fracture thru the threads of the bolt outside the nut 55
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- Bolt Lubrication Black, lubricated bolts & nuts: oily to
touch when delivered & installed 56 Galvanized nuts should be
lubricated w a visible lubricant
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- 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
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- 58 Only area local to bolt influences slip behavior Portions
outside striped areas will not influence slip performance of
connection
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- Faying Surfaces Loose scale or rust must be removed prior to
making connection 59 Removal should be done by blasting or wire
brushing
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- 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