Ko'prik tirgaklari, barjalar ko'prik qoziqlari yoki haddan tashqari issiqlikda kengayish bo'g'inlarining burilishlari: pastki qavatning cho'kishini aniqlash va darhol burish¶

Suv bosgan daryoning taqa girdobi magistral ko‘prigining suv osti poydevor qoziqlari ostidan chuqur gidravlik tirgak qirini qazganda, beton tayanch daryo tubiga 15-60 santimetr (6-24 dyuym) tushib ketguncha, qochib ketgan barja yoki yuk tashuvchi kema yoki ko‘prikni yo‘qotganda. o'n minglab tonna kinetik energiyaga ega delfin (tomirlar ittifoqi) yoki yozgi issiqlik gumbazi (40°C+ / 104°F+) ko'prikning zanglagan po'latdan barmoq yoki modulli kengaytiruvchi bo'g'inlarni siqilish termal zo'riqishiga qadar beton yo'l pastki yoki po'lat truss xordlarini yuqoriga yuqoriga ko'tarilib, katta yo'l tezligida 45 graduslik rampaga yopib qo'yadi, haydovchilar 30 dan 120 soniyadan kamroq vaqtga ega bo'ladilar ** urush chizig'idan oldin to'xtash va to'xtash chizig'ini aniqlash, tirbandlikka tushib qolishdan. Amerika Qo'shma Shtatlari va butun dunyo bo'ylab, ** suv toshqini paytida ko'prikning gidravlikasini tozalash avtomagistral ko'prigi buzilishining №1 sababidir (accounting for nearly 60% of all collapses), undan keyin kema/barja ittifoqlari va ortiqcha yuk/termik burilish kuzatiladi. Mahalliy favqulodda yordam raqamiga qo'ng'iroq qiling (AQSh va Kanadada 911, Yevropa Ittifoqi bo'ylab 112, Buyuk Britaniyada 999) bizning telefonimiz orqali. favqulodda raqamlar darhol katalogni o'qing, Ko'prik identifikatsiya raqami (BIN) yoki Milepost ni dispetcherga yuboring va birodarlarimiz bilan maslahatlashing ko'prikning yopilishi, paromning yopilishi va izolyatsiya qilingan orol yoki yarim orol ta'minoti inqirozi, mashina suvda, va sel toshqinlari.

Yaqinlashib kelayotgan ko'prik qulashi, barja ittifoqi yoki termal kengayish bo'g'ini portlashidan omon qolish uchun Federal avtomobil yo'llari ma'muriyati tomonidan o'rnatilgan to'rtta protokolni bajarish kerak.FHWA Ko‘priklarni tekshirish milliy standartlari [NBIS] va HEC-18 Ko‘priklardagi tozalashni baholash), Transport xavfsizligi milliy kengashi (NTSB), AQSh Sohil xavfsizlik xizmati (USCG) va AASHTO: ** beshta vizual va teginishli qulashdan oldingi indikatorlarni aniqlash (a sudden dip in the bridge guardrail/parapet horizon line, a dropped expansion-joint step-off, swaying streetlight poles, massive log-jam debris rafts piled against piers, or rhythmic metallic "rifle-shot" pings)**, xavfli chiroqlar va uzoq nurlar bilan avtomobilingizni yaqinlashayotgan qirg‘oq bo‘ylab burilish paytida darhol beqaror ko‘prik oralig‘ini orqaga yoki orqaga burish (off the span itself) yaqinlashib kelayotgan avtomashinalarning boʻsh joyga haydashini toʻxtatish, barja urishi, zilzila yoki konstruktiv nola paytida koʻprikda qolib ketganingizda, xavfsizlik kamarlarini yechish va elektr avtomobil oynalarini oldindan agʻdarish va barjaning qochib ketishi haqida bir vaqtning oʻzida xabar berish. 911 va AQSh qirg'oq xavfsizligi (VHF Channel 16) shuning uchun avtomagistral ma'murlari masofa tushishidan oldin avtomatik ko'prik-darvoza to'siqlarini ishga tushiradi.

Buni hozir qiling¶

1. Ko‘prikga haydashdan oldin yaqinlashib kelayotgan tirqish yoki yiqilishning №1 ko‘rinishini aniqlang: Asfaltga emas, balki beton parapet devoriga, to‘siq va yorug‘lik ustunlarining yuqori chizig‘iga qarang. Suv osti ko‘prigi o‘rnatilganda (scour failure) yoki po'lat to'sin sinishi, qorong'u asfalt qoplamasi ko'pincha chuqurlikni yashiradi, ayniqsa kechasi yoki kuchli yomg'irda. Ko‘prik yon panjaralarining gorizontal ko‘rish chizig‘iga, bo‘yalgan chiziqli chiziqlarga va vertikal kobra boshli ko‘cha chiroqlari ustunlariga o‘rgating: agar bitta ko‘cha chiroq ustuni chiziqdan tashqariga qiyshaygan bo‘lsa, to‘siq chizig‘i pastga cho‘kib yoki egilib iskala ustida yoki qorong‘u gorizontalni ko‘rsangiz** 5-to-30-centimeter [2-to-12-inch] vertical step-off**) at an expansion joint, SLAM ON YOUR BRAKES before crossing onto the bridge.
2. Agar barja yoki kema ko‘prik ustuniga ursa (Allision), or You Feel the Bridge Deck Drop, Sway Sideways, or Shudder Violently While You Are On It: Do NOT Stop on the Suspended Span, Drive Off Immediately or Reverse Behind an Intact Land Abutment. After a barge tow or container ship strikes a bridge support pier, a fracture-critical steel truss or prestressed concrete girder bridge may hang briefly by bent rebar or secondary bracing for 15 to 90 seconds before progressive collapse drops the entire span into the channel. If the roadway ahead of you is still connected, accelerate smoothly off the bridge onto solid land; if the span ahead has already separated or dropped, stop short, throw your transmission into Reverse (or sprint on foot toward the nearest solid-earth shoreline abutment), and get completely off the suspended structure.
3. If You Are Trapped on a Bridge That Is Shuddering, Sagging, or Being Approached by an Out-of-Control Ship/Barge: Roll Down All Car Windows Immediately and Unfasten Seatbelts While Moving Toward Shore. If a bridge span collapses into a river or bay (15 to 60+ meters [50 to 200 feet] tushish), mashinalar ** da suvga urdi50 to 100 km/h (30 to 60 mph)**, crushing the front radiator/battery (which instantly kills power to electric windows) and submerging into dark, turbulent current within seconds. The moment you hear a bridge groan, see a vessel drifting toward the piers, or feel a deck drop: roll all four windows completely down, unlock all doors, release children from car seats, and unbuckle your seatbelt if your car is stopped on the span so you can exit through the open window the instant the car hits the water.
4. Once You Are Safely Off the Bridge on Solid Ground (Behind the Approach Abutment): Block the Approach Lanes With Your Hazard Lights / Flares and Wave Oncoming Drivers to Stop (Highway-to-Vessel Darkness Trap). In major historical bridge collapses (including the 1980 Sunshine Skyway Bridge, the 2002 I-40 Webbers Falls barge allision, and the 1987 Schoharie Creek scour collapse), the majority of fatalities occurred after the span had already fallen, when oncoming cars and semi-trucks drove at 100 km/h (65 mph) off the broken edge in rain, fog, or darkness because they could not see the missing span below the horizon crest. Park your vehicle on the solid earth roadbed (at least 30 meters / 100 feet BEFORE the bridge abutment) with all hazard flashers, high beams, and road flares lit, and stand safely behind the roadside guardrail waving a flashlight or bright jacket to stop approaching traffic.
5. For Extreme-Heat Expansion Joint Buckling ("Thermal Blowup" yoqilgan 38°C+ / 100°F+ Days): Never Attempt to "Jump" a Buckled Concrete Slab or Protruding Steel Finger Joint at Highway Speed. When extreme heat expands concrete bridge decks and jammed expansion joints lock up, the concrete slab or steel joint plate erupts upward into a 15-to-60-centimeter (6-to-24-inch) jagged ramp or open gap exposing the river below. Hitting a buckled expansion joint at highway speed shears off front suspension axles, ruptures oil pans/EV battery packs, and launches vehicles over the bridge parapet wall. Brake firmly in a straight line (do not swerve violently near a low bridge railing), stop in your lane with hazard lights on, and call 911 + State DOT.
6. If You Witness a Barge Tow or Ship Collide With ANY Bridge Pier (Even If the Bridge Still Looks Intact from the Water or Shore): Call 911 AND Hail the U.S. Coast Guard on VHF Channel 16 Immediately. Even a "glancing" barge bump that knocks away timber/concrete fender pilings or cracks a concrete pier column can leave a highway or railroad bridge one heavy freight train or semi-truck away from catastrophic collapse (as occurred in the 1993 Big Bayou Canot Amtrak disaster, where a barge displaced a rail bridge span by 1 meter in fog 8 minutes before a passenger train arrived). Give the exact Bridge Name, Highway/Rail Line, and Waterway Mile Marker so 911 and the DOT Traffic Management Center (TMC) can shut down highway and rail traffic within 60 seconds.

Decision tree: Recognizing bridge pier scour, barge allision, and thermal joint buckling in real time¶

flowchart TD
    A["Motorist, Boater, or Pedestrian Approaching or Crossing a Bridge During Flood, Extreme Heat, or Barge/Ship Transit"] --> B{"What structural hazard or warning sign are you observing?"}
    B -->|"Flooded River + Massive Tree Debris Raft Against Piers, Guardrail Horizon Dip, Tilted Light Pole, or Step-Off at Joint"| C["SCENARIO 1: Hydraulic Pier Scour / Foundation Settlement"]
    B -->|"Runaway Barge Tow / Cargo Ship Drifting Toward Pier OR Just Struck Pier/Fender"| D["SCENARIO 2: Vessel Allision (Barge / Ship Strike)"]
    B -->|"Extreme Heat (38°C+/100°F+) + Concrete Slab Tent-Buckled Upward, Steel Finger Joint Popped Up, or Loud Rifle-Shot Bang"| E["SCENARIO 3: Thermal Expansion Joint Lockup / Deck Blowup"]
    C --> F{"Are you currently ON the bridge span or BEFORE the bridge abutment?"}
    D --> F
    F -->|"ON THE BRIDGE SPAN"| G["ROLL WINDOWS DOWN NOW -> Do NOT stop on suspended span -> Drive forward off bridge if deck intact OR reverse/sprint back behind solid land abutment"]
    F -->|"BEFORE THE BRIDGE ABUTMENT (On Solid Earth)"| H["STOP AT LEAST 30m (100 ft) BEFORE ABUTMENT -> Turn on Hazards/Flares -> Block approach lanes to stop oncoming cars from driving into void -> Call 911 + DOT"]
    G --> I{"Did the bridge span collapse into the water with vehicles?"}
    I -->|"YES: Vehicles in Water"| J["Car in Water Protocol: Unbuckle seatbelt -> Exit through open/broken side window BEFORE car sinks -> Swim to shore upstream of debris -> Call 911 & USCG Ch 16"]
    I -->|"NO: Escaped onto solid ground"| H
    E --> K["Brake firmly in a straight line (do NOT swerve into bridge parapet) -> Stop behind buckled joint with hazard flashers on -> Call 911 & DOT with Bridge ID #"]

Part 1: The 5 Pre-Collapse Structural Warning Signs Every Driver Must Know¶

Whether a bridge is failing from underwater flood scour, corrosion of fracture-critical steel gusset plates or post-tensioning tendons, a barge strike, or extreme-heat thermal buckling, the structure gives off five unmistakable physical clues in the minutes or hours before total span collapse:

2-qism: stsenariy bo‘yicha chuqur sho‘ng‘ish (to‘qmoq, barja ittifoqi va termal burilish)¶

1-stsenariy: Suv toshqinidan kelib chiqqan gidravlik ko‘prik tirgaklari (FHWA HEC-18 Mexanika)¶

Nima uchun 1987-yildagi Schoharie Creek Thruway Bridge (Nyu-York), 1995-yilgi I-5 Arroyo Pasajero ko‘prigi (Kaliforniya) va 2009-yildagi Malahide viaduct (Irlandiya) haydovchilar kesib o‘tayotganda to‘satdan suv bosgan daryolarga qulab tushdi? 1. Ko'prikni tozalashning uch turi: - Mahalliy Pier Scour: Pirsning yuqori oqimiga tushgan suv pastga sho'ng'iydi va poydevorda taqa girdobini hosil qiladi va qoziqlar atrofida chuqur konussimon teshik ochadi. - Kontraktsion shilinish: Keng suv bosgan daryo sopol qirg‘oqlar orasidagi tor ko‘prik orqali siqib o‘tganda (yoki ildizi ag‘darilgan daraxtlar to‘dasi bilan to‘sib qo‘yilganda), suv tezligi keskin tezlashadi (Bernoulli / continuity effect), ko'prikning to'liq eni bo'ylab butun daryo o'zanini pastga yo'naltirish. - Abutment Scour: Aylanayotgan uyg'onish girdoblari (wake eddies) eat away the earthen highway fill behind the concrete wingwalls at the ends of the bridge, creating a hollow cavern underneath the highway approach asphalt right where cars enter the bridge. 2. Why the "Approach Asphalt Sinkhole" Is Just as Deadly as a Dropped Span: - Even if the concrete bridge piers survive on deep bedrock pilings, abutment scour frequently washes out the gravel fill directly beneath the first 3 to 6 meters (10 to 20 feet) of highway pavement leading onto the bridge. - Yupqa 15-centimeter (6-inch) crust of blacktop hangs over an empty cavern until the next car's front tires punch straight through into the raging river below. Never drive onto a flooded bridge approach if you see cracks, water bubbling up through the pavement, or washed-out guardrail posts at the wingwalls.

Scenario 2: Barge Tow and Cargo Ship Bridge Allisions (Highway & Rail Bridges)¶

In maritime and civil engineering, when a moving vessel strikes a stationary bridge pier, it is called an allision. Because water is incompressible and vessels carry immense mass: - A standard 15-barge inland river tow on the Mississippi, Ohio, or Illinois River weighs 22,000 to 27,000 metric tons; an ocean-going container ship or bulk carrier entering a coastal harbor or canal weighs 50,000 to 150,000+ metric tons. - Even at a slow drifting speed of 6 knots (11 km/h / 7 mph), a barge tow or cargo ship delivers a horizontal impact force exceeding 10,000 to 100,000+ kilonewtons (1,000 to 10,000+ tons-force), instantly shearing unarmored concrete columns or steel trestle bents if the vessel misses or overwhelms the protective fender system / rock island dolphins.

What to Do If You Are Driving on a High-Level Harbor Bridge or River Crossing and See a Ship or Barge Out of the Channel: 1. Visual Clues of a Vessel Losing Control ("Dead Ship" or Rudder Failure): - Yuk kemasining pambli chiroqlari va ko'prik uyi chiroqlari to'satdan miltillaydi yoki qorong'ilashadi (main generator/engine blackout), muhandislar favqulodda sharqdan qayta ishga tushirishga urinayotganda voronkadan qalin qora tutun chiqmoqda, bir yoki ikkala kamon langarlari to‘q sariq uchqunlar va zang tutuni yomg‘iri bilan tushib, kemani to‘xtatib turishga harakat qilmoqda yoki kemaning shoxi 5 yoki undan ko‘proq qisqa, tez zarba bermoqda (xalqaro dengiz harakati to‘xtab bo‘lmaydi. yo'l"). - Ichki daryolarda ko'p barjali tirgak ** keng tomonga buriladi (sideways)* ko‘prik ustunlari ustidagi daryo oqimiga ("atrofida"), ya'ni daryo oqimi po‘lat bog‘lovchi simlarni uzishdan oldin barjalar yonbag‘irlarini to‘g‘ridan-to‘g‘ri ko‘prik ustunlariga siqib chiqaradi ("breakaway barges"). 2. Ko‘prik palubasidagi 60 soniyalik omon qolish oynangiz: - Never stop your car on the bridge span to film the ship or barge with your phone. - Darhol barcha oynalarni pastga aylantiring, osilgan truss/to‘sinli oraliqlardan qattiq quruqlikka yaqinlashish tomon tezlaning va agar ko‘prikda oldinda harakat to‘xtatilsa, mashinangizni parkga qo‘ying, kalitlarni kontaktda qoldiring va ko‘prikdan piyoda yugurib, er tayanchining orqasidagi.

Stsenariy 3: Haddan tashqari issiqlik kengayish bo'g'inining blokirovkasi, pastki bukilish va tortma ko'prigi "Termal siqilish"¶

Har bir ko'prik harorat ta'sirida kengayadi va qisqaradi (a 300-meter [1,000-foot] steel or concrete bridge span expands by 10 to 20 centimeters [4 to 8 inches] between winter and a 40°C [104°F] summer afternoon). To absorb this growth, bridges use steel finger joints, modular elastomeric strip-seal joints, and sliding PTFE/rocker bearings. 1. How Extreme Heat Causes a Highway Bridge "Thermal Blowup": - Over years of service, winter road salt, sand, and incompressible gravel pack tightly into expansion joint gaps, or steel rocker bearings rust solid ("frozen bearings"). - When an extreme heatwave heats the sunlit bridge deck to 55°C to 65°C (130°F to 150°F), the expanding concrete slabs have nowhere to go. Axial compression builds past 20 to 30 MPa (3,000 to 4,500 psi) until the concrete deck slab explodes upward in a tent-shaped buckle, or a steel expansion-joint plate shears its anchor bolts and pops 20 to 40 cm (8 to 16 inches) straight up into the traffic lane. - In Steel Truss Bridges: If a frozen bearing prevents a steel truss bridge from expanding on a 40°C day, the lower or upper steel chords can visibly bow sideways (lateral-torsional thermal buckling), dropping the roadway deck 15 to 30 cm. 2. Movable Drawbridges (Bascule, Swing, and Vertical-Lift Bridges) Sticking Open in Heatwaves: - On hot summer days, movable steel drawbridges expand by several centimeters, causing the movable steel leaves to jam tightly inside their closed locks (or expand while open for boat traffic so the leaves cannot close back down). - Municipal fire departments or DOT crews often have to spray river water across the steel bridge deck for 30 to 60 minutes to cool and shrink the steel enough to close the locks. Never drive past lowered drawbridge warning gates, if a thermally jammed bascule leaf is partially unlatched, vehicle weight can cause the counterweighted leaf to tip unexpectedly.

Part 3: How to Report a Critical Bridge Defect So DOT Engineers Close the Span Immediately¶

Every public highway and railroad bridge in the United States, UK, Canada, and Europe carries a unique Bridge Identification Number (BIN) or Structure Number stamped on a metal placard on the concrete abutment wingwall or guardrail end, and every railroad bridge over a roadway or waterway has a blue-and-white Emergency Notification System (ENS) sign listing the railroad's 24-hour dispatch phone number and DOT Crossing / Milepost Number.

When calling 911 / 112 / 999 to report a barge strike, pier scour settlement, or buckled expansion joint: 1. State the Words "IMMINENT BRIDGE STRUCTURAL FAILURE , CLOSE THE BRIDGE IMMEDIATELY" First: Dispatchers receive thousands of routine pothole calls; make it clear that a structural pier, girder, or expansion joint has failed or been struck by a vessel so State Police and DOT are dispatched with Code 3 lights and sirens to block both ends of the bridge. 2. Give the Exact Location: Route number, direction of travel (Northbound / Southbound), river/creek name, nearest exit or mile marker, and the Bridge Number if visible. 3. Describe the Specific Structural Clue: State whether (a) a barge/ship struck a pier, (b) the guardrail horizon line or deck has visibly sagged/dropped, © steel joint plates have buckled upward exposing rebar/water below, or (d) a truck struck an overhead bridge girder (overheight strike) leaving bent steel or hanging concrete over the lanes.

First aid and water-rescue instructions on this page are for emergency guidance only and never replace formal training. We recommend taking an accredited First Aid, CPR, and Water Safety course from the American Red Cross, St John Ambulance, or your national Red Cross or Red Crescent society.

Mintaqaviy favqulodda raqamlar va agentlik protokollari¶

• United States: Call 911 immediately to have State Police and your State Department of Transportation (DOT Traffic Management Center) close the bridge. If a barge tow or ship strikes a bridge pier on any navigable waterway, also hail the U.S. Coast Guard (USCG) immediately on Marine VHF Channel 16 (156.8 MHz) or call the nearest USCG Sector Command Center (33 CFR 165 Regulated Navigation Areas & emergency waterway closures). If a barge or vehicle strikes a railroad bridge, call the 24/7 Railroad Emergency Notification System (ENS) 1-800 number posted on the blue sign at the bridge/crossing (or give the dispatcher the USDOT Crossing Inventory Number) so the railroad dispatcher can send an immediate Positive Train Stop (PTC) / Emergency Radio Roll Call to halt approaching trains. Bridge safety is governed by the Federal Highway Administration (FHWA) National Bridge Inspection Standards (NBIS, 23 CFR Part 650), FHWA HEC-18 (Evaluating Scour at Bridges) (which mandates a Plan of Action [POA] and real-time flood closure thresholds for every Scour-Critical Bridge [NBIS Item 113 Code <= 3]), and AASHTO LRFD Guide Specifications for Vessel Collision Design of Highway Bridges.
• United Kingdom: Call 999 immediately for Police and Coastguard response. For structural emergencies on motorways and major A-roads, call National Highways on 0300 123 5000 (England), Traffic Scotland (0800 028 1414), or Traffic Wales (0300 123 1213). CRITICAL UK RAIL BRIDGE RULE: Every road bridge over or under a railway in Great Britain displays a yellow-and-black Network Rail Bridge Identification Plate with a 3-letter code and bridge number: if any vehicle or barge strikes a railway bridge, call the Network Rail 24-Hour Emergency Line immediately on 03457 11 41 41 (yoki 999) and quote the bridge code before any train crosses. Scour management follows Design Manual for Roads and Bridges (DMRB) Standard BD 97/12 (The Assessment of Scour and Other Hydraulic Actions at Highway Structures) and CIRIA C742 (Manual on Scour at Bridges and Other Hydraulic Structures).
• Canada: Call 911 immediately, and for vessel strikes on navigable waters contact Canadian Coast Guard (CCG) Marine Communications and Traffic Services (MCTS) on VHF Channel 16 yoki *16 on a cell phone. Provincial bridge inspections and scour closures follow the Canadian Highway Bridge Design Code (CSA S6) and Transport Canada Navigation Protection Program.
• European Union: Call 112 across all EU member states, and alert coastal/inland waterway authorities on VHF Channel 16 / RIS (River Information Services). Bridge structural design for thermal expansion, hydraulic scour, and ship/barge impact is governed by Eurocode 1 (EN 1991-1-5 Thermal Actions & EN 1991-1-7 Accidental Actions , Impact from Ships and Road Vehicles).
• Australia and New Zealand: Call 000 (Australia) or 111 (New Zealand). Bridge scour and vessel impact standards follow Austroads AS 5100 and Waka Kotahi Bridge Manual. See favqulodda raqamlar.

Tez-tez beriladigan savollar¶

How can you tell if a bridge is about to collapse from underwater flood scour before driving onto it?¶

Before driving onto any bridge over a flooded river, look ahead along the top horizontal sightline of the concrete side barriers, guardrails, and overhead streetlight poles rather than just looking at the wet pavement. If an underwater bridge pier has been undermined by hydraulic scour and settled into the riverbed, you will see a visible dip, sag, or V-shaped kink in the guardrail horizon line, a streetlight pole leaning out of alignment, or a sharp vertical step-off (ledge) at an expansion joint. You should also refuse to cross if a massive raft of uprooted trees and logs is piled against the upstream piers or if floodwater is touching the horizontal steel or concrete girders.

What should you do immediately if you are on a bridge when a barge or cargo ship strikes a pier (allision)?¶

Do not stop on the suspended bridge span to watch or film. Immediately roll down all four electric car windows (so you can escape if the span drops into the water and shorts out your car's electrical system), and if the roadway ahead is still intact, drive smoothly off the bridge onto solid land behind the shoreline abutment. If the span ahead has already separated or traffic is gridlocked on a shuddering bridge, reverse or abandon your vehicle on foot and run back behind the solid-earth abutment, then block oncoming traffic with hazard lights so approaching drivers do not drive off the broken edge.

Why did so many cars drive off the edge of collapsed bridges like the Sunshine Skyway or Schoharie Creek after the span had already fallen?¶

On arched high-level bridges and unlit rural highway bridges during heavy rain, fog, or darkness, a driver's low-beam headlights only illuminate 45 to 60 meters (150 to 200 feet) of wet black asphalt ahead, and the vertical crest of the bridge hides the missing span until the car is within 1 to 2 seconds of the precipice. Once you escape or stop short of a collapsed bridge, your highest priority (while staying on solid ground at least 30 meters / 100 feet before the abutment) is turning on hazard flashers, high beams, or flares across the approach lanes to warn oncoming drivers before they reach the gap.

Why do concrete bridge decks and expansion joints buckle upward during extreme summer heatwaves?¶

Concrete and steel bridge spans expand significantly when solar radiation heats the roadway surface to 55-65 degrees Celsius (130-150 degrees Fahrenheit). Normally, steel finger joints and elastomeric expansion joints absorb this movement. However, if expansion joints are packed with incompressible winter gravel or steel rocker bearings have rusted solid, thousands of tons of compressive thermal stress build up along the deck until two concrete slabs violently buckle upward like a tent or shear the bolts on a steel expansion plate. Brake in a straight line without swerving into the bridge railing, turn on your hazard lights, and call 911 and the DOT.

Tegishli qo'llanmalar¶

• Bridge closure, ferry shutdown, and isolated island or peninsula supply crisis
• Car in water
• To'fon toshqinlari
• Railroad crossing blocked for hours by stopped freight train: emergency vehicle bypass and never crawling under cars
• Extreme heat

Manbalar va rasmiy ko'rsatmalar¶

• Federal avtomobil yo'llari ma'muriyati (FHWA, U.S. Department of Transportation): Hydraulic Engineering Circular No. 18 (HEC-18: Evaluating Scour at Bridges), National Bridge Inspection Standards (NBIS, 23 CFR Part 650: Scour-Critical Bridge Plans of Action & Fracture-Critical Member Inspections), and Technical Advisory T5140.23 (Evaluating Scour at Bridges).
• National Transportation Safety Board (NTSB) & U.S. Coast Guard (USCG): Highway & Marine Accident Reports on Bridge Scour and Vessel Allision Disasters (Schoharie Creek Thruway Bridge Collapse, I-40 Webbers Falls Barge Allision, Sunshine Skyway Bridge Allision, Big Bayou Canot Rail Bridge Displacement, and Francis Scott Key Bridge Allision: Automated Bridge Warning & Closure Systems).
• American Association of State Highway and Transportation Officials (AASHTO): LRFD Bridge Design Specifications (Thermal Expansion Joint Movement, Extreme Event II Vessel Collision Design Loads, and Hydraulic Scour Limit States).
• United Kingdom Construction Industry Research and Information Association (CIRIA) & Network Rail: CIRIA C742 (Manual on Scour at Bridges and Other Hydraulic Structures), DMRB BD 97/12, and Network Rail Bridge Strike Prevention and Emergency Reporting Protocol.
• Prof. Gordon Giesbrecht (University of Manitoba) & Association for the Advancement of Automotive Medicine (AAAM): Vehicle Submersion Survival Protocol ("SWOC": Seatbelts, Windows, Out, Children , First 60-Second Floating Escape Window).