2.36 Bridge Inspections
Introduction
The Department of Works, Services and Transportation is responsible for
construction, inspection and maintenance of bridges in the provincial road
system. The Transportation Services Division has responsibility for roads
and bridges. Within the Division, the Bridge Office is responsible for
bridges whereas the Roads Section is responsible for culverts. The
Department’s Bridge Inspection Database shows there are 910 structures
with inspection records, 823 identified as bridges and 87 identified as
culverts. These culverts include corrugated steel structures referred to as
multiplates and various size pipes and configurations but would not
include what is commonly known as ditch culverts. Of the 823 bridges,
715 are six metres or longer and are subject to inspection by a
Departmental engineer, 54 bridges are less than six metres and subject to
inspection by highways maintenance staff and the remaining 54 do not
have any length indicated in the database.
Information on the locations of bridges is maintained in binders of
topographic maps. The Department’s activities relating to bridge
inspections include the completion of a bridge inspection report by
highway maintenance personnel, regional engineers, and bridge engineers
located at head office. The Department’s policy is to maintain individual
files for each of the 823 bridges. Furthermore, bridge inspection
information is entered from the bridge inspection reports to a
computerized information system at the Department.
In 1996 the Office of the Auditor General identified a number of issues
with the bridge inspection program and recommended the Department
establish a bridge inspection program that included objective standards for
assessing bridge conditions and ensuring data in the bridge information
system was current and accurate.
Scope and
Objective
We completed our review in December 2002. The objective of our review
was to assess whether the Department has: a bridge inspection program
with objective standards for assessing bridge conditions, a bridge
information system that is current and accurate and a rehabilitation and
replacement plan based on information gathered from bridge inspections.
Conclusions
The Department has a bridge inspection policy; however, it is not
documented and there is no documented approval of the policy. The
bridge inspection policy is not risk based; instead, the policy is to inspect
bridges six metres or longer every two years. A bridge may be inspected
more frequently if the Bridge Office is made aware of safety issues;
however, this is a reactive inspection and not proactive based on bridges
with the highest degree of risk for safety. Contrary to the Department’ s
policy to inspect bridges six metres or longer every two years, 379 of the
Auditor General of Newfoundland and Labrador 543
2.36 Bridge Inspections
715 bridges requiring such inspection have not been inspected within the
past two years. Furthermore, 47 of these 379 bridges had an overall rating
showing that they were in a poor or unsafe condition and 39 of the 379
bridges did not have an overall rating.
The Department does not have documented guidelines to assist the five
regional engineers and six bridge engineers when completing bridge
inspections to ensure that inspections are consistent among staff and
across regions. Our review indicated there were inconsistencies in bridge
condition ratings resulting from completed inspections.
The bridge inspection database maintained by the Department containing
information input from the bridge inspection reports is incomplete and
inaccurate. For example:
h
At the time of our review in December 2002, the bridge inspection
database did not include information on inspections performed
after 2001.
h
Fourteen bridges were not in the database and twelve bridges
included should have been removed.
h
Information on the length of 54 bridges is not included in the
database. As a result, it is not possible, from our review of the
database, to determine whether these bridges were six metres or
longer and whether they should be inspected by engineers within
the two year inspection requirement.
h
54 bridges in the database did not have an overall rating.
h
Not all information relating to the condition of the bridges is
entered into the database. For example, the results of load tests to
determine the safety of a bridge is not entered.
The Department’s process relating to bridge rehabilitation and
replacement requires improvement. For example:
h
544 Auditor General of Newfoundland and Labrador
The Department does not have a long-term plan to enable
Government to consider future funding requirements in an orderly
manner and to estimate how much funding will be required or
when the funding would be required to rehabilitate or replace
ageing bridges so that all bridges are brought up to a fair or good
condition. This may also help avoid a significant fiscal burden of
rehabilitating or replacing a large number of bridges in a short
time-frame. Although the Department’s database does provide for
2.36 Bridge Inspections
input of information regarding suggested rehabilitation and
replacement cost and date, we found that 202 of the 360 bridges
indicated as being 30 years of age or older did not have any
estimates for future rehabilitation or replacement costs or the dates
that the work should be completed.
h
The Department does not use a risk based model to identify bridges
for rehabilitation or replacement. Instead, on an annual basis the
Bridge Office uses listings prepared by the five regions along with
their own knowledge of bridge conditions and opinions with
regard to safety and economics to set its annual work priorities.
h
Officials at the Department have indicated that the funding for the
bridge maintenance program is not sufficient. If the required
maintenance is not performed on bridges, there will be extra costs
for rehabilitation work and the work will be required sooner.
Bridge inspection is necessary to determine the safety of bridges on our
Findings and
Recommendations highways and to determine required maintenance, rehabilitation and
replacement. In order for the Department to apply a risk model to
determine the priority and frequency of bridge inspections and to
determine the priority for maintenance, rehabilitation and replacement, it
requires detailed information about each of its 715 bridges. A complete
and accurate bridge information database would be a useful tool to identify
this information. Our review of the Department’s bridge inspection
program indicated the following:
Bridge Inspection Policy
The Department’s bridge inspection policy is not risk based; instead, the
policy is to inspect bridges at least every two years. A bridge may be
inspected more frequently if the Bridge Office is made aware of safety
issues; however, this is a reactive inspection and not proactive based on
bridges with the highest degree of risk for safety.
Bridge inspections are not always being performed in accordance with
Departmental policy which requires that bridges six metres or longer be
inspected at least every two years. Figure 1 shows that 379 (124 + 222 +
33) of the 715 bridges have not been inspected in the last two years and that
47 of these 379 bridges had an overall rating showing that they were in a
poor or unsafe condition. A further 39 of the 379 bridges did not have an
overall rating.
Auditor General of Newfoundland and Labrador 545
2.36 Bridge Inspections
Figure 1
Bridge Inspection
Bridges six metres or longer
Overall Rating
Good
Condition
Fair
Condition
Poor
Condition
Unsafe
Condition
176
106
37
2
15
336
> 2 years < 5 years
48
49
19
2
6
124
> 5 years < 10 years
108
62
20
2
30
222
17
9
4
-
3
33
349
226
80
6
54
715
Last Inspection
< 2 years
> 10 years
Totals
Not
Rated
Totals
Source: Department’s Bridge Inspection Database
Bridge inspection reports are not required to be completed for bridges
under six metres. In 1997 the Bridge Office decided not to require
regional office engineers to inspect bridges less than six metres in length
and opted to have highway maintenance staff perform inspections of those
structures. Inspections of bridges six metres and over are documented by
an inspection report and entered into the Department’s database whereas
any inspection reports prepared by maintenance staff are not required to be
entered into the database. If there is any question of bridge safety by
highway maintenance staff they are required to request inspection of the
structure by engineers in either the regional office or the Bridge Office.
The Department’s bridge inspection policy is not documented and there is
no evidence the policy is approved.
Two of the six bridges identified in the database as being unsafe were
indicated in the database as requiring further inspection by the Bridge
Office; however, there was no documentation in the bridge files to
substantiate that further inspections were carried out.
We were unable to determine whether the appropriately qualified
personnel completed inspections of 289 of the 715 bridges because the
database did not indicate who performed the inspection. A further review
of the 289 records showed 70 were either not rated or rated poor to unsafe
and 66 of the 70 were inspected more than 2 years ago.
546 Auditor General of Newfoundland and Labrador
2.36 Bridge Inspections
Bridge Inspection Guidelines
The Department does not have documented guidelines to assist the five
regional engineers and six bridge engineers when completing bridge
inspections. Guidelines are necessary to increase the objectivity of the
ratings, to ensure consistency in rating the condition of bridge components
by engineers in either the Regional Offices or the Bridge Office, and to
ensure that bridge inspection forms are properly completed. Guidelines
are also necessary so highway maintenance staff or regional office staff are
aware of which specific bridge deficiencies are to be referred to the Bridge
Office for further inspection.
For 98 of the 715 records included in the database we found that the
general overall condition was either not rated or was rated better than the
condition of the substructure and/or the superstructure. Discussions with
staff at the Department confirmed that the overall bridge rating should be
no higher than the lowest rating for the substructure and/or the
superstructure. This indicates that, as a result of not having inspection
guidelines, there are inconsistencies in the bridge condition ratings. As an
a example, the Winterhouse Brook Bridge was rated overall as good while
the superstructure was rated as poor.
Winterhouse Brook Bridge
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2.36 Bridge Inspections
The bridge inspection forms were not always fully completed.
example:
For
h
35 structures were indicated as being over navigable or nonnavigable water; however, they were not rated for adequacy of
waterway.
h
297 structures did not have ratings for bearings yet 220 of the 297
were rated for bearing seats. There may be exceptions but this is
generally inconsistent because a structure with a bearing seat
would normally be expected to have a bearing that should be rated.
Bridge Information
Information at the Department shows there are 910 structures with
inspection records, 823 identified as bridges and 87 identified as culverts.
The Department maintains information on these structures in three forms a Bridge Inspection Database, a hard-copy file, and a series of
topographic maps which indicate the location of various structures. Given
the number of bridges in the Province, it is important that the Department
has a means to keep accurate information on their condition. Our review
indicated the following:
The Bridge Inspection Database is intended to capture information on the
bridges in the Province and could be used to prioritize and manage
inspections as well as maintenance, rehabilitation and replacement.
Therefore, it is necessary that the database contain information that is
complete and accurate. We found that the database was neither complete
nor accurate. For example:
h
At the time of our review in December 2002, the bridge inspection
database did not include information on inspections performed
after 2001.
h
14 bridges were not in the database: 3 were no longer part of the
provincial road system and 11 were existing structures that were
missed. The three bridges which are no longer part of the
provincial road system are used for cabin access and, therefore,
should be in the database and inspected. Of the 11 that were
missed, 7 were constructed in 2001.
h
12 bridges were incorrectly included in the database: 6 were
duplicates, 5 were not the responsibility of the Department, and 1
was demolished.
548 Auditor General of Newfoundland and Labrador
2.36 Bridge Inspections
h
54 bridges in the database did not have information with respect to
length. Therefore, as the database did not indicate whether the
bridges were six metres or longer, we were unable to determine,
from our review of the database, whether these bridges should be
inspected by engineers in either the regional offices or the Bridge
Office every two years. Twenty nine of these 54 bridges have not
been inspected since 1997 or earlier.
h
54 bridges in the database did not have an overall rating.
h
Not all information relating to the condition of the bridges is
entered into the database. For example, the results of load tests to
determine the safety of a bridge is not entered.
Although the Department maintains a hard-copy file for the bridges, not
all information is included. For example, inspection reports, load test
results, and non-routine Bridge Office inspection results are not always
put in the file.
Bridge Rehabilitation and Replacement
The Canadian Highway Bridge Design code, the standard for bridge
construction indicates that, until recently, a 50-year life was assumed. The
actual life of a bridge can differ from this assumption depending on many
factors such as the amount and weight of traffic, and use of road salt on the
structure. In addition, the 50-year life estimate is contingent on regular
maintenance and rehabilitation being undertaken, if not, the expected
lifespan would be shorter. Regular maintenance is a yearly activity and
would consist of, for example, cleaning out expansion joints, patching
holes in the asphalt and clearing curbs of sand and salt accumulated from
winter ice and snow control. Rehabilitation is generally completed in the
range of 25 years after construction and could involve replacement of
girders, deck, handrails or curbs. Such rehabilitation can restore a bridge
to near the condition at construction.
Only 615 of the 715 bridges in the database has information on the year of
construction. The average age of these 615 bridges is 29.3 years.
Information on the age and condition of the bridges is outlined in Figure 2.
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2.36 Bridge Inspections
Figure 2
Condition of bridges by age
Latest inspections to 31 December 2001
Overall Rating
Good
Condition
Fair
Condition
Poor
Condition
Unsafe
Condition
1 - 29
190
49
2
0
14
255
30 - 49
113
133
49
3
26
324
50 - 78
8
12
10
2
4
36
38
32
19
1
10
100
349
226
80
6
54
715
Bridge age
Not in database
Totals
Not
Rated
Totals
Source: Department’s Bridge Inspection Database
As Figure 2 shows, after 29 years, there are proportionately more bridges
rated as being in a poor or unsafe condition. Therefore, as the average age
of bridges is 29.3, it is likely that significant funding will be required in the
future to maintain the bridges in a good condition.
Our review of the Department’s maintenance, rehabilitation and
replacement program for bridges indicated the following:
h
The Department does not have a long-term plan to estimate how
much funding will be required or when the funding would be
required to rehabilitate or replace ageing bridges so that all bridges
are brought up to a fair or good condition. Although the database
does provide for input of information regarding suggested
rehabilitation and replacement cost and date, we found that 202 of
the 360 (324 + 36) bridges indicated as being 30 years of age or
older did not have any estimates for future rehabilitation or
replacement costs or the dates that the work should be completed.
The development of long-term plan is necessary to enable
Government to consider future funding requirements in an orderly
manner and avoid a significant fiscal burden of rehabilitating or
replacing a large number of bridges in a short time-frame.
550 Auditor General of Newfoundland and Labrador
2.36 Bridge Inspections
h
The Department does not use a risk based model to identify bridges
for rehabilitation or replacement. Instead, on an annual basis each
of the five Regions submit a prioritized listing of bridges for
rehabilitation and replacement based on their knowledge of the
region. The Bridge Office uses these listings along with their own
knowledge of bridge conditions and opinions with regard to safety
and economics to set its annual work priorities.
Although the Department’s database could be used as a source of
information to set priorities for bridges relative to all other bridges
in the Province, as a result of the incompleteness and inaccuracies
in the database, it is not possible for the Department to use it to
request funding for the highest risk bridges in the Province.
h
Officials at the Department have indicated that the funding for the
bridge maintenance program is not sufficient. If the required
maintenance is not performed on bridges, there will be extra costs
for rehabilitation work and the work will be required sooner.
Recommendations
The Department should:
h
develop and implement a documented and approved risk based
bridge inspection policy;
h
prepare guidelines to ensure that inspections are consistent among
staff and across regions;
h
ensure that the bridge inspection database is complete and
accurate;
h
develop and implement a long-term plan for future funding
requirements for the rehabilitation and replacement of bridges.
Department’s Response
The Department is developing a risk-based bridge inspection policy. This
policy will be further developed to include guidelines for engineering staff
in the application of the policy. As well, a seminar will be held with
regional staff in May 2004 to review these guidelines and ensure
consistency in bridge inspections. The Department is committed to
improving the bridge inspection process, which will require increased
engineering staff time applied to report generation and data entry.
Improvements to the database have been initiated, with a focus on data
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2.36 Bridge Inspections
processing integrity and the reorganization of the forms used for data
collection.
At present, the Department has four bridges which are labelled unsafe in
the database. These ratings were assigned by the person at the regional
level who did the inspections. Follow up inspections were done by a
Senior Bridge Engineer or the Chief Bridge Engineer. These more
detailed inspections indicated no imminent safety concerns and were
upgraded from unsafe. It is acknowledged that the database was not
upgraded to reflect this change. Had these inspections indicated
otherwise, immediate action would have been taken. Two of these bridges
are on cabin roads or other low volume roads, with very light traffic. The
department is still assessing its options with respect to these bridges. The
other two bridges are on department maintained roads and are monitored
regularly. They have both been identified for consideration for
rehabilitation in the next fiscal year.
With respect to the funding situation of the bridge program, the
Department strives to optimize the funding allocation available for
rehabilitation and replacement of provincial bridge structures. The
Department will continue to evaluate all structures for load capacity, with
priority given to the routes most affected by heavy loads. The Department
is currently developing an eight year program to address the issues related
to aging bridge infrastructure.
552
Auditor General of Newfoundland and Labrador