Handbook for Bridge Inspections - TSP2

9.1 ELEMENTS IN THE GROUND
Original Level
~-..I....- \--1" .f-:7--.~
/ :""
. r . 9~· ~ ~
\le'/el after Erosion
Example 9. 1-6
The original undenvater ground level has been eroded
down to the same level as the bottom of the
base foundation slab due to insufficient protection
against erosion.
Type of Damage: 103
Scouring/erosion of river course
Degree of Damage &
Consequences:
3C
Cause of Damage: 13
Poor design solutions
Procedures: Replenish with suitabl e materials and
install protection against erosion within one year.
•
,
Original level
\ " •
•
"
•
• "
"
•
Level after Erosion
~
Example 9. 1-7
The original underwater ground level has altered
due to erosion with severe consequences for the
carrying capacity. The ba ll ast co nsists of too fine a
grade of material.
Type of Damage:
Scouring/erosion of river course
Degree of Damage &
Consequences:
Cause of Damage:
Construction fa ult
103
4C
38
Procedures: Replen ish wit h suitab le materials and
install protection against erosion in the course of
s ix months.
Example 9.1-8
The base foundation slab has suffered under-scouring
as the result of a serious flood. Carrying capaci
ty has been greatly reduced.
Type of Damage: 103
Scouring/erosion of river course
Degree of Damage &
Consequences:
4C
Cause of Damage: 73
Flooding
Procedures: The bridge should be closed until
repairs have been carried out" immediate infilling
with concrete under the foundations, replenish ing
w ith suitable materials a nd installing protection
against erosion to the same level as the origi nal
river bed.