Damage Illustrations

Potential Bridge Damage Bridge Component / DamagePossible Cause Approach Slab or Pavement  Raised, lowered, cracked, or buckled  Longitudinal forces  Lateral spread; Slope failure Abutment and/or Foundation  Tipping or other displacement  Cracking  Movement of supporting soil  Movement of soil behind abutment  Loads exceeding shear capacity, especially if superstructure smashes into the backwall, cheekwalls, or shear blocks  Liquefaction Superstructure  Collapse of one or more spans  Span misalignment  Girder damage  Bowing, dips  Deck damage: spalling, exposed rebar  Displacement beyond capacity of the bridge seat  Horizontal displacement  Abutment or pier damage or movement  Beam failure due to excessive shear or moment  Superstructures tend to move off a highly skewed seat Bearings  Toppled  Unseating, misalignment  Sheared or bent anchor bolts  Use of high, potentially unstable bearings  Frozen (non-functioning) bearings Restrainers or other Seismic Retrofits  Damage to restrainers  Insufficient capacity  Improper installation Joints and Connections  Misalignment, spalling, cracking  Inadequate development length of longitudinal reinforcement in adjacent member  Poor choice of connection details (insufficient translational restraint for pinned connection, etc.) Pier (wall, stem, columns or capbeam)  Cracking from flexural or shear failure  Crushing or mushrooming  Longitudinal reinforcement tension failure  Buckling of longitudinal reinforcement  Torsional failure  Uneven settlement of a footing  Insufficient confinement (number, size or spacing of bars)  Poor reinforcement details (hooks, laps, etc.) Other  Damage to bridge railing  Consequence of damage to other elements

Potential Bridge Damage (continued) Bridge Component / DamagePossible Cause Pier (wall, stem, columns or capbeam)  Cracking from flexural or shear failure  Crushing or mushrooming  Longitudinal reinforcement tension failure  Buckling of longitudinal reinforcement  Torsional failure  Uneven settlement of a footing  Insufficient confinement (number, size or spacing of bars)  Poor reinforcement details (hooks, laps, etc.) Other  Damage to bridge railing  Consequence of damage to other elements

APPROACH

Figure 14: Moderate Damage - Approach Slab Settlement at the Abutment. Note the cracking of the concrete barrier as well.

Figure 15: Moderate to Major Damage - Approach Settlement After Northridge

Figure 16: Moderate to Major Damage – Settlement of Bridge Approach

Figure 56: Settlement at the bridge approach, likely caused by soil settlement around the abutment (Northridge EQ)

Approach: Minor Settlement

Figure 15: Minor Damage – Parapet Crushing / Spalling

Figure 60: Moderate Damage: Transverse Movement of the Abutment Wingwall

Settlement at Approach; Spalling

Minor cracking of curb

Serious erosion behind wingwall

SUPERSTRUCTURE

Figure 57: Moderate Damage – Bowing of Parapet and Handrail

Figure 58: Misalignment of curb line and bowing of railing. Notice that the white edge line is slightly shifted at the joint.

Figure 17: Severe Damage: Deck Collapse

Figure 18 and 19: Severe Damage: Deck Collapse

(I-10 and SR 118 Damage from Northridge EQ

Figure 24: Moderate Damage – Flexural Cracking of Concrete Girder (KTC)

Figure 32: Severe Damage: Steel girder buckling

Figure 28: Moderate Damage: Crack in web of steel girder. Flag condition.

Figure 27: Minor Damage - Web stiffener damage. Note paint chipping.

Joint – Minor Cracking, Separation

Pounding Damage

Damage from Rockfall in Peru. An earthquake caused rocks to fall from the mountain that was looming over this truss bridge in Peru, causing impact damage to the bottom chord, a primary structural member. In addition to the obvious deformation, cracked welds were discovered. Collateral Damage

JOINTS & BEARINGS

Figure 16: Moderate Damage - Vertical and horizontal movement at joint indicates possible bearing or girder displacement and damage

Figure 20: Minor Damage: Misaligned Finger Joint

Joint – Minor Cracking, Separation

Figure 21: Minor Damage: Transverse Movement Along the Centerline (Check for bearing damage.)

Figure 22: Moderate Damage: Differential Settlement and Expansion Joint Damage

Figure 23: Moderate Damage - Spalled Concrete

Figure 49: No Damage: Tilted Rocker Bearings. Movement due to Thermal Loads (INDOT)

Figure 53: Severe Damage. Rocker Bearing Failure

Figure 54: Severe Damage. Missing Abutment Bearing After Northridge After Northridge

Damage to Anchor Bolts. Mark ‘YES’ for column #4.

Figure 30: Minor Damage. Damage to anchor bolts

SECONDARY MEMBERS

Figure 25: Minor Damage - Buckled Bracing Element.

Figure 31: Moderate Damage - Fracture of lower lateral bracing.

SOILS / GEOTECHNICAL / FOUNDATION

Figure 33: Ground movement indicating possible foundation problem

Figure 55: Evidence of Liquefaction near a pier

Tilted pier wall

Volcano shaped sand boil is evidence of soil liquefaction

SUBSTRUCTURE (PIERS & ABUTMENTS)

Figure 34: Minor Damage - Cracking and Spalling of the Concrete Cover at the Column Base

Figure 37: Severe Damage - Mid-height Flexural Damage

Figure 36: Moderate Damage - Support damage at top of pier Minor Damage – Fascia concrete

Figure 35: Moderate Damage - Compression Failure at top of Concrete Column

Spalling and splice failures at column base

Moderate to Severe Damage - Spalled column, buckling of primary reinforcement, compression failure, and lack of adequate transverse reinforcement to brace the primary reinforcement

Figure 38: Severe Damage - Confinement failure

Moderate Damage: Column Shear

Figure 40: Severe Damage: Brittle Shear Failure

Figure 41: Severe Damage: Weld failure of column longitudinal reinforcement

Figure 42: Severe Damage: shear failure (1971 San Fernando Earthquake)

Figure 44: Minor Damage: Shear Cracking at the Abutment wing-wall.

Figure 47: Moderate Damage: Abutment slumping and rotation failure

Figure 48: Moderate Damage: Spalling and cracking of abutment, movement at ground level. Note that the rebar is not rusting, an indication that damage is recent Northridge Earthquake, California

not new damage. As observed in the first image, there is also no damage to the rail curb line, or utilities. Mark ‘No’ for column 6.

Figure 61: Minor Damage to wingwall and end-wall

Figure 50: Minor Damage – cracks induced by steel bearing

OTHER (UTILITIES)

Figure 59: Movement of the trusses at Pier 23 of the San Francisco Oakland Bay Bridge during the Loma Prieta earthquake. The shoe (at the right) hit the two pipes that carried electric wires and dented them. These dents indicated that there was at least 3 to 4 inches of movement.