NHI SAFETY INSPECTION OF IN-SERVICE
BRIDGES COMPLETE STUDY GUIDE 2026 |
VERIFIED ANSWERS | 100% CORRECT |
GRADED A+| PASS GUARANTEED
Degradation - ANSWER general and progressive lowering of channel bed due
to erosion, usually over relatively long channels
What is channel misalignment? - ANSWER When the stream will flow against
the bridge abutments.
How do you determine if a bridge needs an underwater inspection? -
ANSWER When you can't inspect with a probing rod and/or waders.
What is SCUBA diving? - ANSWER It is self contained underwater breathing
apparatus, the most common type of self-contained diving equipment used.
What is Surface-supplied diving? - ANSWER Is a diving technique that uses a
breathing gas supply that originates above the water surface and is transported
underwater to the diver via flexible umbilical hoses.
What is level 1 of diving inspection? - ANSWER It is normally conducted over
the total exterior surface of each underwater inspection (100 percent)
, What is level 2 of diving inspection? - ANSWER It is intended to detect and
identify high-stress, damaged, and deteriorated areas that may be hidden by surface
growth (10 percent).
What is level 3 of diving inspection? - ANSWER Is a highly detailed inspection
of a structure or structural member of great concern, or a member where extensive
repair or possible replacement is contemplated (as needed).
What is Crack Propagation Gages (CPG)? - ANSWER Is used to either monitor
the length of an existing crack or monitor an area that is highly susceptible to
cracking.
What is Dye Penetrant (DPT)? - ANSWER Can be used to define the size of
surface flaws in steel.
What is Eddy Current Testing (ECT)? - ANSWER Uses AC current to detect
small surface or near-surface cracks and flaws in steel.
What is Magnetic particle testing (MT)? - ANSWER Is used on ferromagnetic
materials to detect near-surface deficiencies in steel.
What is Magnetic Flux Leakage (MFL)? - ANSWER Is used to detect the
location and extent of corrosion in post-tensioning and prestressing strands in
concrete girders, and the breakage of wires or strands in Post-tensioned tendons
and Prestressed strands.
, What is Ultrasonic Testing (UT)? - ANSWER Can be used on a flat surface to
evaluate a member's thickness or to determine if a member contains discontinuities
by using high-frequency sounds to generate images.
What are Ultrasonic thickness depth meters (D-meters)? - ANSWER Uses a
dedicated straight beam transducer to measure the thickness of steel members.
What is a Phased Array Ultrasonic Testing (PAUT)? - ANSWER Can be used to
detect discontinuities in steel.
What is Acoustic Tomography? - ANSWER Is beneficial in detecting the
deteriorated regions of timber members.
What is Stress Wave Timing? - ANSWER It investigates the presence of flaws
and decay in timber by determining the travel time of stress waves as they
propagate from the source to the receiver.
What is Transverse Vibration of Structural Systems? - ANSWER It provides
information about the condition of a structure. It estimates the elastic modulus (E)
and moment of inertia (I) of the system.
What is Quality Control (QC)? - ANSWER Are procedures that are intended to
maintain the quality of a bridge inspection and load rating program.
What is Quality Assurance (QA)? - ANSWER Is the use of sampling and other
measures to assure the adequacy of procedures in order to verify or measure the
quality level of the bridge inspection and load rating program.
, aggradation - ANSWER progressive buildup of the longitudinal profile of a
channel bed due to sediment deposition
headset migration - ANSWER degradation of the channel that is associated
with abrupt changes in the streamed elevation and then migrates upstream (Niagara
Falls)
general scour - ANSWER lowering of streamed across watery at the bridge.
caused by short-term changes in the downstream water elevation (recurring)
contraction scour - ANSWER removal of streamed material under structure
only (direct result of accelerated stream velocity). can be triggered by natural
constrictions
local scour - ANSWER occurs around an obstruction placed within the stream
clear-water scour - ANSWER occurs when there is no bed material transport
upstream of the bridge
live-bed scour - ANSWER occurs when local scour at the substructure is
accompanied by bed material transport in the upstream waterway
streambank damage - ANSWER first mode of bank failure
onset of lateral stream migration
BRIDGES COMPLETE STUDY GUIDE 2026 |
VERIFIED ANSWERS | 100% CORRECT |
GRADED A+| PASS GUARANTEED
Degradation - ANSWER general and progressive lowering of channel bed due
to erosion, usually over relatively long channels
What is channel misalignment? - ANSWER When the stream will flow against
the bridge abutments.
How do you determine if a bridge needs an underwater inspection? -
ANSWER When you can't inspect with a probing rod and/or waders.
What is SCUBA diving? - ANSWER It is self contained underwater breathing
apparatus, the most common type of self-contained diving equipment used.
What is Surface-supplied diving? - ANSWER Is a diving technique that uses a
breathing gas supply that originates above the water surface and is transported
underwater to the diver via flexible umbilical hoses.
What is level 1 of diving inspection? - ANSWER It is normally conducted over
the total exterior surface of each underwater inspection (100 percent)
, What is level 2 of diving inspection? - ANSWER It is intended to detect and
identify high-stress, damaged, and deteriorated areas that may be hidden by surface
growth (10 percent).
What is level 3 of diving inspection? - ANSWER Is a highly detailed inspection
of a structure or structural member of great concern, or a member where extensive
repair or possible replacement is contemplated (as needed).
What is Crack Propagation Gages (CPG)? - ANSWER Is used to either monitor
the length of an existing crack or monitor an area that is highly susceptible to
cracking.
What is Dye Penetrant (DPT)? - ANSWER Can be used to define the size of
surface flaws in steel.
What is Eddy Current Testing (ECT)? - ANSWER Uses AC current to detect
small surface or near-surface cracks and flaws in steel.
What is Magnetic particle testing (MT)? - ANSWER Is used on ferromagnetic
materials to detect near-surface deficiencies in steel.
What is Magnetic Flux Leakage (MFL)? - ANSWER Is used to detect the
location and extent of corrosion in post-tensioning and prestressing strands in
concrete girders, and the breakage of wires or strands in Post-tensioned tendons
and Prestressed strands.
, What is Ultrasonic Testing (UT)? - ANSWER Can be used on a flat surface to
evaluate a member's thickness or to determine if a member contains discontinuities
by using high-frequency sounds to generate images.
What are Ultrasonic thickness depth meters (D-meters)? - ANSWER Uses a
dedicated straight beam transducer to measure the thickness of steel members.
What is a Phased Array Ultrasonic Testing (PAUT)? - ANSWER Can be used to
detect discontinuities in steel.
What is Acoustic Tomography? - ANSWER Is beneficial in detecting the
deteriorated regions of timber members.
What is Stress Wave Timing? - ANSWER It investigates the presence of flaws
and decay in timber by determining the travel time of stress waves as they
propagate from the source to the receiver.
What is Transverse Vibration of Structural Systems? - ANSWER It provides
information about the condition of a structure. It estimates the elastic modulus (E)
and moment of inertia (I) of the system.
What is Quality Control (QC)? - ANSWER Are procedures that are intended to
maintain the quality of a bridge inspection and load rating program.
What is Quality Assurance (QA)? - ANSWER Is the use of sampling and other
measures to assure the adequacy of procedures in order to verify or measure the
quality level of the bridge inspection and load rating program.
, aggradation - ANSWER progressive buildup of the longitudinal profile of a
channel bed due to sediment deposition
headset migration - ANSWER degradation of the channel that is associated
with abrupt changes in the streamed elevation and then migrates upstream (Niagara
Falls)
general scour - ANSWER lowering of streamed across watery at the bridge.
caused by short-term changes in the downstream water elevation (recurring)
contraction scour - ANSWER removal of streamed material under structure
only (direct result of accelerated stream velocity). can be triggered by natural
constrictions
local scour - ANSWER occurs around an obstruction placed within the stream
clear-water scour - ANSWER occurs when there is no bed material transport
upstream of the bridge
live-bed scour - ANSWER occurs when local scour at the substructure is
accompanied by bed material transport in the upstream waterway
streambank damage - ANSWER first mode of bank failure
onset of lateral stream migration
