Structural Collapse Operations II Course Objectives l Describe

Structural Collapse Operations II

Course Objectives: l Describe the six sided survey l State the principle weakness of light frame and heavy URM structures l State 3 methods to monitor structural stability l State the two main objectives of a shoring system

Objectives Continued: l State three areas where shoring placement should be considered l Calculate the estimated weight of a given rubble pile l State the components of a shoring system l State greatest safety concern when performing lifting operations

Objectives Continued: l State the possible indicators of secondary collapse l State the duties of a given team assignment l Construct a horizontal shore, vertical shore, T-spot shore and raker shores

Six Sided Survey

SIDES OF STRUCTURE l Street or address side is side A SIDE THREE SIDE TWO SIDE FOUR SIDE ONE 700 Block Alpha Street

Quadrants within Structure l Also use and MARK column grid Quad. B Quad. C E Quad. A Quad. D 700 Block Alpha Street

MULTI - STORY STRUCTURES l Ground Floor is 1, Second is 2, Third is 3, etc. l First Floor below grade is B-1, Second is B-2, etc.

Basic Building Types Review l Light frame-Wood frame l Heavy wall-URM, tilt-up, low rise walls l Heavy floor-concrete frame buildings/bridges l Pre-cast concrete buildings

Light (Wood) Frame l 1 -4 stories in height l Principal weakness in lateral strength of the walls l Walls become “wracked” causing offsetting of the floors l Masonry chimneys can crack and fall l Structures can shift off of foundation l Fire load significant

Light Frame – House Separated Entry Roof Tile falls off Brick chimney cracked & may fall Elec Gas & Water Racked cripple wall Cripple Wall Type Masonry veneer falls off Hi - Footing 6 s Most likely Aftershock hazards = Falling heavy objects

Racked House I. 4 -1

Heavy wall URM l Parapets, full walls fall off due to inadequate anchors l Often times weak mortar l Walls can separate from wood floors/roof l Broken bricks often line streets

Heavy Wall URM Buildings Elec URM corner Gas Water URM can fall 20 ft from bldg. face Unsupported roof & floor Slip off bearing Loose equip Cracked wall piers Cracked parapets & split or peeled walls Most Hazards are Brittle & Lethal falling objects 10 s

Heavy Floor Concrete Frame l Columns break at intersections with floor beam l Short columns in exterior walls get high tension/shear forces by surrounding concrete l Bending/punching shear failure at intersections of flat slabs and columns l Weak concrete can compound problems

Heavy Wall - TU Buildings Separation of roof members from wall bearings Slip at all interior roof connections Wall top tension failure Leaning walls Cracked walls Aftershocks can cause additional wall & roof collapses 1 s

Pre-Cast Concrete Buildings l Joint failures between roof/floors/walls l Wall panels separate from the building and fall l Progressive collapse can be caused by joint failure between column and beam or slab and wall panel

Precast Concrete Building Partly fallen slabs & beams Elec Gas Cracked walls w/ broken conns Overload from upper collapse Loose debris Leaning wall check conns Water Cracked corbels Beam collapse ? 5 s Aftershocks cause loosely connected parts to shift & fall. Debris piles of large parts can shift & trap rescuers

May Co Garage Badly damaged in Whittier 87 EQ 1. 4 -36

Simple Hazard Mitigation l Avoid – Need effective barrier system l Removal – Lift off, push over, pull down l Exposure reduction – How long do we need to be in the area? – Risk is a function of severity and exposure – limit time exposed to hazard – limit number of personnel exposed Similar to Time, Distance, & Shielding Rule used in Hazmat

Other Hazard Mitigation l Vertical & Lateral Shoring – system with slow failure mode l Lateral Bracing l Vertical Tieback – use crane to hang structure l Monitor - with alarm & escape system l Recognize & Refer Hazard (hazmat)

Methods to Monitor STABILITY

Devices Previously Used in US&R l l l Plumb bob Levels Engineers transit Electronic tilt meter & levels Crack measuring devices

Levels placed to monitor column rotation (buckling) between 2 nd & 3 rd floors OKC-37

Use of Devices l Plumb Bob hung from small structure to compare to a point on the ground - observe change in a leaning structure – Use of Laser Pointer or Laser Level could be more accurate & effective l Transit / theodolite to establish a vertical line that will compare a point on a dangerous building to a point on the ground to detect additional tilt / movement

Shoring

BASIC DEFINITION SHORING for US&R is the TEMPORARY SUPPORT of ONLY THAT PART of a DAMAGED STRUCTURE that is REQUIRED for CONDUCTING OPERATIONS at REDUCED RISK

WE INSTALL RESCUE SHORING TO PROTECT “US”

SHORING SIZE-UP l identify structural hazards, damage and potential victim locations l determine best method to mitigate the hazard and damage l determine the type & placement of shoring systems in relation to structural hazards and potential victim location

DOUBLE FUNNEL PRINCIPLE COLLECT LOAD l NEED POSTS / SHORES with ADJUSTABILITY & POSITIVE CONNS l NEED LATERAL BRACING l NEED SYSTEM with FORGIVENESS DISTRIBUTE LOAD

The SHORING SQUAD SHORING TEAM CUTTING TEAM SHORING OFFICER LAYOUT FF MEASURING FF CUTTING FF SHORING FF TOOL & EQUIP FF

GENERAL RULES OF THUMB NORMAL CAPACITY OF UNDAMAGED CONSTRUCTION l One undamaged wood framed floor will support one damaged wood floor l One undamaged steel framed floor will support one damaged steel floor l It takes two undamaged reinforced concrete floors to support one damaged concrete floor

NORMAL CAPACITY OF UNDAMAGED CONSTRUCTION Useful info for shoring multi-story buildings. – shoring should be placed under damaged beams, etc. – multi-level shoring should align from story to story l The thickness of debris from heavy, exterior walls, etc. must also be taken into account – In URM buildings, wall debris can easily weigh more than a normal story l

VERTICAL SHORING SYSTEMS l l l l WOOD POSTS ELLIS CLAMPS T - SPOT SHORE WINDOW / DOOR LACED POSTS CRIBBING STEEL PIPE TRENCH SHORES METAL FRAMES & JOIST l PNEUMATIC SHORES l SPECIALTY SHORES l

SCREW JACK by ELLIS l Adjustable metal foot for 4 x 4 and 6 x 6 wood posts l 6 inch adjustment - set half way to get 3 in. up & down l Metal Foot is stronger than wood post l Use sole to spread load

ELLIS SHORES - 4 x 4 adjustable 2 s 7 -0 max 6” 12” 6” 2 Ellis Clamps to make a pair of 4 x 4 into Adjustable 4 x 4 shore l Need Ellis Jack l Failure Mode is by clamp crushing the side grain of the post - Gives Warning 12 -0 max l Need

Ellis jack, clamps Shor-7

Vertical Shores Ellis clamps Ellis Foot Shor-6

PNEUMATIC SHORES AIRCRAFT ALUMINUM 18” EXTENDING TO 16’ DO NOT USE AIR TO SET THESE STRUTS IN A STRUCTURAL COLLAPSE WORKING LOAD VARIES DEPENDING ON LENGTH

PNEUMATIC SHORES l l l Adjustable shore with length up to 16 ft - Manufactured by Airshore, Paratech, & Holmatro Have swivel & other feet Should be set manually using adjustable collar or sleeve nut DON’T USE AIR SET IN US&R Working Load decreases with length and should be based on tests using swivel ends Best use is as initial shore 2 s

Airshore - A. R. T Shown as single, vertical shore - plus triple, column shore w/special plate at each end ARTvert 1

Airshore - A. R. T showing window & door shores w/U type connection at top ARTvert 2

“T” Spot Shore for initial stabilization only

T - SPOT SHORE Temporary Shore Basically Unstable Limit Header to 3 feet and center on Load Standard, 12” x 12” Gusset Post strength is based on height as for Vertical Shore

The WINDOW SHORE STABILIZE WINDOW OPENING SUPPORT DAMAGED HEADER 1 inch THICKNESS FOR EVERY FOOT OF HEADER OPENING

Construct In-place Method

Pre-constructed Method, Build frame with plywood gussets at each corner, insert in opening, then add Wedges at side and

Window Shore In Masonry wall

THE DOOR SHORE RESUPPORT ENTRANCE SUPPORT WALL BREACH 1 inch THICKNESS FOR EVERY FOOT of HEADER LENGTH

VERTICAL SHORE RESUPPORT UNSTABLE FLOORS OR ROOFS POSTS UNDER FLOOR BEAMS MID-POINT BRACING AT 9 ft CEIL. HT (Posts over 8 ft plus header & sole)

VERTICAL WOOD SHORING • 3/4” Ply gussets ea. end ea. interior post, 1 side min. (dbl gusset + add on opposite side of diag brace at post bottom) • 2 x 6 diag braces • Full width wedges w/ keeper nails. (can’t adjust them) • Nail 2 x 6 diag. brace w/516 d to sole, header and to each post

Reinforce access w/shoring

HORIZONTAL SHORE STABILIZE PASSAGEWAYS 2 - 3 SUPPORT STRUTS DEBRIS WEIGHT WILL DETERMINE THE SIZE AND # OF STRUTS NEEDED

Provide horizontal shoring in access corridor

SOLID SOLE RAKER l The Raker Shore of Choice l Generally Erected at 45 Degree Angle l Can Be Utilized on Solid Ground As Well As Earth l Pre-assemble and Carry Into Position l Must Erect Minimum of Two Shores l Used to Re-support Unstable or Leaning Walls

RAKER SHORE ANGLES DEGREE PITCH LENGTH 45 deg 12/12 17 60 deg 12/7 14

Calculating length of rake: l 60 degree angle raker: Insertion height in feet multiplied x 14 = length of rake – Example: 8’ x 14 = 112” (9’ 4”) l 45 degree angle raker: Insertion height in feet multiplied x 17 = length of rake – Example: 8’ x 17 = 136” (11’ 4”)

Raker end cuts

ANGLE CUTS 1 1/2 RETURN CUT 45 DEGREE CUT

SOLID SOLE RAKER 3 5 4

FULL TRIANGLE (FIXED) RAKER SOLID SOLE TYPE 2 x 4, 2 x 6 Nailed Cleat, 17 -16 d min. 4 x 4, 4 x 6 Wall Plate w/ drill-ins to wall 4 x 4, 6 x 6 Raker depending on length and lateral & mid-point bracing Solid sole w/ nailed cleat, wedges and anchor system at end or drill-ins thru solid sole Build these away from wall and assemble at wall in pairs or more as system with lateral bracing Solid sole 2 x 6 braces to reduce L/d of raker

Solid sole rakers

SPLIT SOLE RAKER l l l Second Option for Raker Shoring Generally Utilized in Earth or Where Debris is at the Base of the Wall Erected the Same Except for the Base of the Shore Can Be Partially Pre-erected Before Installation Should be erected at 60 degree angle, whenever possible

SPLIT SOLE RAKER

SPLIT SOLE RAKER BASE (also use for Sloped Floor Shore on Earth) U-CHANNEL 4 x 4 x 18” with 12”x 3/4 x 12” ply gussets ea side WEDGES inside U SOLE PLATE 3 -2 x 6 x 18” or 2 Layers 3/4”x 18”sq plywd

HIGH PRESSURE AIR BAGS

HIGH PRESSURE AIR BAGS l Characteristics – Neoprene/butyl rubber – Steel kevlar reinforced – Variety of sizes – Maximum capacity is calculated at 1 inch of lift – Very low capacity at max height

HIGH PRESSURE AIR BAGS l Application – Maximum stack of two high – Lift is limited to capacity of small bag – Larger bag on bottom – Keep pressure in large bag less than small bag – Centers of bags MUST be aligned

HIGH PRESSURE AIR BAGS LOAD INCREASED SURFACE AREA = INCREASED LIFTING CAPACITY COLUMN OF AIR BASE OF SUPPORT

HIGH PRESSURE AIR BAGS LOAD C O L U M N O F A I R BASE OF SUPPORT AIR BAG INFLATED REDUCED SURFACE AREA CONTACT

HIGH PRESSURE AIR BAGS

HIGH PRESSURE AIR BAGS I. D. Tag is right on Bag

HIGH PRESSURE AIR BAGS & CRIBBING

SPREADING & PUSHING

LIFTING AND STABILIZING IRREGULAR OBJECTS

PIPES & CYLINDERS

WEDGES AND CRIBBING

SHIMS (WEDGES) Use of shims to change direction

“MARRYING” WEDGES RIGHT WRONG

CRIBBING 6000 lbs. per contact point Four point system Nine point system

CRIB STABILITY LOAD MUST BE CENTER 1/3 OF CRIB

CRIBBING

CALCULATING WEIGHTS

CALCULATING THE WEIGHTS OF COMMON MATERIALS LENGTH x WIDTH x HEIGHT = CUBIC FT l Steel l Concrete 490 lbs. per cubic foot ( pcf) 150 pcf l Earth 100 pcf l Wood 40 pcf

Weights continued: Add 10 to 15 psf for wood/metal interior walls – each floor l Add 10 psf or more each floor or furniture etc. – More for storage l Add 10 psf or more for Rescuers l Concrete or masonry rubble = 10 psf per inch l

CALCULATING THE WEIGHTS OF COMMON MATERIALS LENGTH x WIDTH x HEIGHT x WEIGHT 20’ X 4’ X 2’ = 160 cf x 150 pcf = 24, 000 lbs. 2 feet 4 feet 20 feet

EXAMPLE l Assume that this 20 ft x 30 ft classroom has an 8” thick concrete roof with 6” of debris on it WHAT IS THE TOTAL LOAD TO SHORE ? – – 8” concrete = 100 psf x 20 x 30 = 6” debris = 60 psf x 20 x 30 = Lights, ducts, ceiling, etc. = 5 psf = Rescuers = 10 psf x 20 x 30 = TOTAL 60, 000 lb 36, 000 lb 3, 000 lb 6, 000 lb* -------= 105, 000 lb = 105 Kips * 6, 000 lb Rescuers allows for 24 - 250 lb people Is this reasonable ? If not use more, this is

Structural Hazard Markings Review

STRUCTURE / HAZARDS MARK l Structure relatively safe for S&R ops. There is little chance of further Collapse. – Victims could be trapped by contents – or could be unconscious

STRUCTURE / HAZARDS MARK l Structure is Significantly Damaged. Some areas may be relatively safe, but others may need shoring, bracing, removal, and/or monitoring of hazards – Building could be completely pancaked

STRUCTURE / HAZARDS MARK l Structure is NOT SAFE for Rescue Ops and may be subject to Sudden Collapse. Remote search Ops may proceed at significant risk. If rescue Ops are undertaken, Safe Haven areas, & rapid evacuation routes (with Structure Monitoring) Should be Created.

STRUCTURE / HAZARDS MARK l Arrow next to Marking Box indicates the direction of Safest Entry to Structure

STRUCTURE / HAZARDS MARK l HM HM indicates hazardous material condition in or adjacent to structure. S&R Ops normally will not be allowed until condition is better defined or eliminated.

STRUCTURE / HAZARDS MARK - SUMMARY 15 JUN 92 HM NATURAL GAS OR-1 No entry until gas is turned off. When it’s mitigated, should line out the HM mark and record new date and TF

BUILDING MARKING SYSTEM SEARCH ASSESSMENT MARKING

SEARCH ASSESSMENT MARK 15 JUL 92 1400 HR 2’ x 2’ X near each entry OR-1 First slash made when entering RATS 3 DEAD Crossing slash made as TF exits

BUILDING MARKING SYSTEM VICTIM LOCATION MARKING

VICTIM LOCATION MARKING CA 6 CONFIRMED LIVE VICTIM POTENTIAL VICTIM CA 6 REMOVED VICTIM CA 6 CONFIRMED DEAD VICTIM

Basic Approach to US&R l Identify the – Prioritize Problem l Find Victims – Re-prioritize l Mitigate Hazards – Risk vs Reward l Remove Victims – Medically stabilize l Create no new victims

Basic Building SAR Plan (initial phases) l Reconnoiter – determine structure type – obtain / draw plans – access hazards – interview neighbors, etc. l Prioritize Site – develop hazard mitigation alternatives – callout / listen search – condition of voids & basement

Basic Building SAR Plan (initial phases) l Initial Search – use K-9 in safe & less safe areas – use technical search equip. – use existing vertical shaft opngs – use existing horizontal openings with great care – search from stable to un-stable – re-prioritize vs live finds

Basic Building SAR Plan (main phase - days long ? ) l Selected cutting / removal – cut vert opngs & re-search – initial shoring for access – avoid unshored overhead slabs, etc. – re-check shoring after cutting & removal – continue - cut opng & re-search – shore victim area for rescue ops – Struc Spec gives continuing aid to rescue