appendix i - maintenence and inspection

8/8/2019 Appendix I - Maintenence and Inspection

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Changing Lives One Bridge at a Time

Volume 3: Suspended Pedestrian Bridg

Part 4: Maintenance and Inspectio

First Editon 20


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Bridge Committee Annual Inspection Form

In order to keep your bridge in the optmum conditon, contnual upkeep is required. An annual

inspecton is essental to maintenance. Following the end of the rainy season, one or more

representatves of the Bridge Commiee must visit the bridge site and go through the following

checklist and complete corresponding maintenance.

Remove any excess mud and debris from the bridge deck.

Ensure weeds and plants growing beneath the bridge do not obstruct the bridge.

Ensure all bolts, screws and nails are in place and tghtened.

Replace deterioratng wood deck panels.

Replace deterioratng crossbeams.

Ensure that fencing is secure. Should any wires be loose or fencing missing, repair or replaceto original conditon.

Check for erosion. Should erosion or scour occur, causing the water to reroute toward the

anchor or approach, contact the local supportng agency and request assistance with a

drainage structure.

Measure the distance between the paint on the cable and the saddle guides (inset boom

right). If more than half meter, local supportng agency immediately and if possible, Bridges

to Prosperity (contact at www.BridgestoProsperity.org).

Additonal Inspecton Notes:

Paint LinePaint Line

SaddlesSaddles

Annual Inspection Pg 1


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16 Volume 3: Suspended Part 4 Maintenance

Section 3:Quality Control Inspection

To ensure an adequate inspecton has been completed for each bridge, a Quality Control Inspecton

& Picture Inventory are required for all quality control inspectons completed on behalf of Bridges to

Prosperity. For those tracking bridges within their own agencies, a filed report is useful to ensure the

contnued maintenance needs are met. Bridges may be inspected without the design engineer on-site and furthermore, by someone without an engineering background. To ensure the evaluaton is

adequate, the submission of pictures provide a visual confirmaton of wrien statements. An As-Built

picture inventory should be on file with the Bridge Registry, which can be located in the final pages of

this manual.

To complete the quality control inspecton, prepare yourself by reading the As-Built Bridge Registry

and spend tme looking through pictures. Take special note of the size of the cables, for this will dictate

the size of torque wrench socket required. If a previous quality control review has been completed,

also review the inspectors comments and concerns. If not familiar with how to use and read a torque

wrench, reference Volume 3, Part 3: Constructon Manual.

3.1 Materials Required

3 meter measuring tape

Digital Camera

Torque Wrench

Socket (sized to correspond to cable diameter)

Pen & paper

Copy of Quality Control Inspecton (Form)

How to read aHow to read atorque wrenchtorque wrench


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3.2 Quality Control Overview

Following the completon of the bridge, a follow-up quality control inspecton must be completed

a minimum of two tmes during the lifetme of the bridge. The first should be completed between

three (3) to five (5) years afer completon, and the second inspecton between five (5) and ten (10).

If the pedestrian bridge contnues to be used beyond 10 years, the quality control inspecton should

be completed every five (5) years. Beyond 30 years, the bridge must be reviewed by an engineer to

ensure safety of cables, structure and decking.

The Quality Control Inspecton Report in Secton 5 includes the following items;

Overall Site Evaluaton

Foundaton Tiers & Towers

Anchors

Cable Conditon

Cable Clamps

Approach Walls & Ramp

Decking

For each sub-secton, an adjoining chapter is included in Secton 4: Maintenance; Secton 4 must be

referenced for both mandatory upkeep items as well as retrofit solutons for bridge concerns found

during the inspectons. Please keep one copy of each report and send a copy to Bridges to Prosperity

(contact at www.BridgestoProsperity.org).


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Quality Control Review& Picture Inventory FormDate: __________

Country: __________________________

Bridge Name:

Name of Inspector: ___________________________

Date: __________

Region: ___________________________

Village: ___________________________

GPS coordinates: ___________________________

Directons to site: _______________________________________________________

_______________________________________________________

Contact informaton of person in community: __________________________

Bridge Span: ________meters

Contact informaton of inspecton partcipants: ___________________________

Observed traffic level: Number of persons: ____________ Time Lapse: ____________

Type of use (bicycle, pedestrian, livestock, etc.) ________________________________

Notes:

Quality Control Pg 1


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Site Evaluation

Inspect the area surrounding the bridge, on both abutments.

Take special note if erosion has occurred and what the

drainage path of run-offwater appears to take. If the erosion

has caused scour, undercung the anchor, approach or

foundat

on structure, reference the maintenance sect

on.For all following sectons, reference Secton 4: Maintenance

to address any possible concerns. If the manual does

not address the specific issue, please contact Bridges to

Prosperity (contact at www.BridgestoProsperity.org).

Include the following pictures on disk or in printed form and

aach to Quality Control Inspecton report;

Profile (from both up and down stream)

Lef and Right abutment general picture

Pictures of bridge in use (people, livestock etc.)

Notes on site evaluaton, include drainage concerns:

Foundation Tiers & Towers

Inspect the foundaton ters and towers. Note the masonry

conditon of towers. Is one able to pick out aggregate with hands?

On either side, verify the base foundaton layer is level (see black

line on picture to right). Note if the foundaton structure appears to

be dipping (orange) towards the water, or slipping (green arrow). If

structure has seled in either manner creatng change of elevaton

of line greater than 30 cm, contact agency responsible for bridge.

Notes on foundaton ters & towers:

Include the following pictures with report:

Concerning masonry degradaton, if any

Pictures from both sides, either abutment

Picture of selement, if any


Figure above: Profile picture

Figure above: Abutment picture


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Anchors

Inspect the area surrounding the anchors (far back side

of approach, on both abutments. Take special note if

erosion has occurred and what the drainage path of run-

offwater appears to take. If the erosion has caused scour,

undercung the anchor, reference the maintenance

secton.

Walk behind the approach, if possible. The view should be

similar to that in the picture to the right. For soil conditons,

the anchor is a large beam, as shown in the picture to the

right. Note if the cable is kinked at the saddles, implying

the cable is not wrapped directly behind the corresponding

cable saddle (handrail on outsides, walkway on inside, as

shown to right).

For rock conditons, the anchor is a cylindrical drum. The

cables also should come straight off the saddles, as shownin the diagram to the boom right. Note is the cable is

kinked.


Picture from behind abutment & ramp, on either

abutment

Lef and Right abutment general picture

Picture/s of erosion or drainage concerns, if any

Notes on anchor, sketch area if drainage concerns:



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Cable Condition

Inspect the cable at all points of inserton into concrete, the

approach or the ground. Inspect general cable conditon and

note if loose strands occur anywhere along the cable.

Note the slide of the cable. Reference the colored mark on

the cable, which originated between guides on saddles. Ifthe amount of movement exceeds 1 % of length of cable

(see Span on Quality Control Page 1), cable slip or excessive

cable stretch has occurred (assume 2% equally divided

between two sides as an upper limit of concern). Please

contact B2P immediately (contact informaton at www.

BridgestoProsperity.org).


Cable inserton into approach, if any corrosion or rust

appears

Pictures of all four (4) handrail saddle pictures: look for

amount of slide for mark on cable.

Cable fraying, if any

Cable Clamps

Inspect all clamps that are visible above ground. Using torque

wrench, document existng torque on each above-ground

clamp. For torque standards, first measure the diameter of

the cable or reference As-Built Bridge Register. Reference the

corresponding minimum torque from the torque requirements

on the following page.

If the measured torque is less than 80% torque required,

re-tghten all above-ground clamps to specified torque. If

actual is less than 60% of specified required torque, notfy

implementng agency immediately to discuss need to rip out

approach or return with additonal clamps.

Include the following pictures with report: Clamp conditon (before re-torque, if required)

If re-torqued, torque technique used for each

Figure above: Handrail saddle

Figure above: Cable at concrete


Figure above: cable clamps

Figure above: Re-torque clamps


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Notes on cable and clamps (include existng torque for

every above-ground clamp):

Approach Walls & Ramp

Inspect the conditon of the approach walls and ramp.

Evaluate and document extent of cracking on concrete

approach ramp. Typical source of crack propagaton is the

inserton point of cable, or selement within the approach.

Note opinion on source of cracks. If cracks between rock

walls exist, look into the approach to evaluate if excessive selement has occurred inside. Note if any

usage issues occur. This may include water pooling, excessive

cracks or bumps in the approach or connecton to ground etc.


Cable inserton into approach if cracks

If separaton between tower and approach, if more than 30cm separaton, note if selement occurred with tower or ap-

proach.

Notes on approach walls and ramp:


Table above: Clamp torque requirements

Figure above: Cracking ramp side-view

Figure above: Cracking


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Decking

Rate the conditon of the deck panels. Note if any

longitudinal deck panels are missing. Note if rot has

occurred and to what extent. Document with pictures,

quantty and extent of rot and opinion of current usability.

Rate conditon of cross beams (transverse beams, likely

will need to go below deck). Note if any cracking between

suspender drill hole and end of beam. Note any structural

damage (split beams, missing sectons of beams etc.).

Note if rot has occurred and to what extent. Document

with pictures, quantty and extent of rot and opinion of

current usability.


General decking conditon

General crossbeam conditon

Decking/crossbeam pictures if rong or other

issues

Notes on approach walls and ramp:

Full-Bridge Photos

CrossbeamsCrossbeams



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Section 4:Maintenance

This secton includes mandatory upkeep items to be completed during every Quality Control Inspecton,

as well as solutons to repair bridge components found to be substandard during inspectons.

The Maintenance chapter includes the following sectons:

4.1 Overall Site Conditon

4.2 Foundaton Tiers & Towers

4.3 Anchors

4.4 Cable & Clamps

4.5 Approach Walls & Ramp

4.6 Decking

4.1 Overall Site Condition

If the Quality Control Inspecton notes that erosion and scour are undermining the bridge structure,

a drainage structure may allow the water to reroute, thus saving the structure from further damage.

Slope protecton and drainage systems are required at sites when excess run-offmay influence the

slope stability. It is recommended to avoid sites where any instability is prevalent. If unavoidable, it is

necessary to drain out the runoffand seepage to ensure the stability of the slope and to avoid under-

scour of structures. Water should be collected as closely as possible to its origin and navigated away

from the bridge structures. A surface catch drain on a slope may be required, drainage around the

structure or both.

Below right if an example subsurface drainage systems, and boom right are example surface drainage

systems. For further details, reference Volume 2.

Surface Drainage

Subsurface Drainage


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4.2 Foundation Tiers & Towers

If the quality control inspecton finds that the masonry structure is degrading, use a cement mortar to

patch the areas. If severe degradaton, consider replacing when possible.

If the structure is found to be slipping (either slipping downhill, or tpping forward), hire a local

engineer to evaluate the stability of the slope. If considered unsafe, close the bridge. It is possible to

reconstruct the structure of the failing side using many of the scrapped materials, but do not relocate

at such a distance that the cables create a lateral load on the opposing side towers.

4.3 Anchors

If the Quality Control Inspecton notes that erosion and scour are undermining the anchor, a drainage

structure may allow the water to reroute, thus saving the structure from further damage. See secton

4.3.1 and reference Volume 2 for further details on drainage structures.

4.4 Cables & Clamps

If the cable is found to be corroding or fraying, estmate the percentage of the cable cross-secton

that has been damaged. If greater than 10% of cable is fraying, evaluate the extent of the damage. If

localized in one point, consider a splice. Reference cable-

manufacturing materials for details. If evaluated to have

extensive damage, close the bridge untl cable can be

replaced with new cables. If this occurs, contact Bridges

to Prosperity to describe situaton, providing pictures and

details when possible (contact at www.BridgestoProsperity.

org).

If the clamps are found to have less than 80% of required

torque, each above-ground clamp must be re-tghtened.

The picture to the top right depicts the cross-sectonal

reducton that is required when the clamps are fully

torqued (assuming drop-forged, not malleable. For more

informaton, see Volume 3, Part 3). Boom

right shows the proper length of the breaker

bar or torque wrench required to apply the

adequate amount of torque.

If the clamps are found to have less than60% of the required torque, additonal

clamps must be added. In severe cases the

approach should be removed to tghten

clamps below ground.

SaddleSaddle

DeadDeadcablecable


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4.5 Approach Walls & Ramp

If the quality control inspecton finds that the approach structure is degrading, use a cement mortar to

patch the areas. If severe degradaton, consider patching with wedge stones.

If the approach ramp is separatng from the tower structure, a method to te back the structures

together is required or the bridge must be closed. This method is beyond the scope of this basic

manual as it will require engineering consultaton.

If the ramp is cracking from selement (not just localized cracking around the inserton points of the

cable), rip out the 5 cm thick concrete ramp top, backfill the approach with additonal well-graded

large aggregate and stone and recover with a fresh layer of concrete, 5 cm thick.

4.6 Decking

If any decking panels are rong through or missing

entrely, they must be replaced. The standard

thickness of a decking board is 5 cm, but verify withthose on site before purchasing. Reference Volume 3,

Part 2 Drawings, specifically the decking drawings for

complete details. Note that the paern of laying the

deck panels requires an alternaton, as shown in the

picture to the right.

If any crossbeams are in need of replacement, either

an additonal board must be aached to the boom as

reinforcement or the beam must be replaced.

If replacement is chosen, start by removing the deck

panels directly above the crossbeam in queston.

Unwrap the fencing in the direct locaton; cung may

be required. Secondly, unwrap the suspenders from

the top of the cable, which likely will require a pipe.

Unwrap the suspender from the crossbeam, originally

with the configuraton shown to the right. Remove

the suspenders completely and aempt to straighten

for reuse. Take new pre-drilled crossbeam and fit into

place. Reference Volume 3, Part 3 Constructon for

details. Complete the process by screwing and nailingthe deck boards back into place. Replace and repair

any damaged fencing before leaving.

appendix i - maintenence and inspection

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