ETSI Methodology 1

LCCMethodology

Håkan Sundquist

Structural Design and Bridges KTH

ETSI Methodology2

There are many requirements on a bridge

Safe for the traffic

Beautiful

Strong

Maintenance and repair friendly

Durable

Economical Environmental friendly

ETSI Methodology3

The classic task10

0 %

Time

PlanningDesign

Construction

Investment decision

Accumulated consumption of

resources

Possibilities to influence the final cost

Inauguration

Con

stru

ctio

n co

st

ETSI Methodology4

The classic bridge design task

1) Technical design 2) Investment

Valuation

LowestInvestment cost

ETSI Methodology5

LCC optimization10

0 %

Time

PlanningDesign

Construction

Investment decision

Accumulated consumption of

resources

Possibilities to influence the final cost

Inauguration

LC

C/C

onst

ruct

ion

cost

Operation and maintenance

Obs change of time scale

ETSI Methodology6

Include maintenance and operation costs

1) Technical design 2) Investment

Valuation

Lowest LCC cost

3) Operation, maintenance and disposal

ETSI Methodology7

Agency or owner costsCost

k k+ik+1 n n+1 m

Time/a1 765432 80

Investment

Repair

Major repair

Disposal

Yearly operation

ETSI Methodology8

The bridge must also contribute economically to the society

1) Technical design

2) Investment

Valuation

Best socitialbenefit

3) Operation,maintenance and disposal

7) Society benefit and

lifetime

ETSI Methodology9

Include society costs during maintenance and repair

1) Technical design

2) Investment

Valuation

Best socitialbenefit

3) Operation,maintenance and disposal

7) Society benefit and

lifetime

4) Society cost during main-

tenance and repair

Include eventual accident costs

ETSI Methodology10

User benefit and cost”Income”

k k+i

k+1

nn+1

m-1

Time/a1 765432 80

Yearly ”income”

Disposal

User costs due to repair

User costs due to major repair

Could increace or decrease due to changes

in traffic

ETSI Methodology11

Costs for the society due to accidents and total failure

Accidents are usually covered by the society and not by agencies like SRA or FinnRA

Cost

k k+i

k+1n n+1 m-1

Time/a1 765432 80

The bridgeFalls down

Ev. societal costs accidents due to

repair

Ev. societal costs due accident due to major

repair

Societal cost due accident when bridge

falls down

Costs with very low probability!!

ETSI Methodology12

LCC Life Cycle Costing LCC is a technique which

enables comparative cost assessments to be made over a specified period of time, taking into account all relevant economic factors initial capital costs future operational and maintenance costs

owner costs user costs society costs

future disposal cost Used methodology is usually the present value of

the total cost of this asset over its lifetime

ETSI Methodology13

LCC scheme

LCC

Agency costs

User costs

Society costs

Planning & design

Construction Operation

Maintenance Repair

UpgradingDisposal

Delay costs

Discomfort

Increased risks

Accidents

Environmental impact

Others

ETSI Methodology14

Definitions

LCC owner or agency LCC = LCCA + LSC + LCCC LCCA = is the cost for acquisition of the project (design,

construction…) by the net present value calculated to a specified time usually the opening of the bridge

LSC = (Life Support Cost) is the cost for future operation, maintenance and repair of the bridge, by the net present value calculated to a specified time usually the opening of the bridge.

LCCC = (Life Cycle Cost Consequence), is the future costs for eventual negative consequences, by the net present value calculated to a specified time, usually the opening of the bridge.

ETSI Methodology15

LSC, the Life Support Cost

LSC = CI + CN CI = is the investment in the necessary equipment

and other resources for the future operation and maintenance

CN is the future cost for operation, maintenance and repair, by the net present value calculated to a specified time, usually the opening of the bridge

The investment part of the maintenance, CI, could be divided in parts

ETSI Methodology16

CI = Investment for operation and maintenance

CI = CIr + CIv + CId + CIt

CIr = spare parts and material CIv = instrument, tools, vehicles that is

needed for inspection and maintenance CId = documentation i.e. drawings and

instruction manuals needed for inspection and maintenance

CIt = education of personnel for operation and maintenance

ETSI Methodology17

The costs are recalculated to one point in time usually the day of opening the bridge

t

owner0 1

T

tt

CLCC

r

•Ct the sum of all costs incurred at time t,•p the real interest rate or a rate taking into account changes in the benefit of the structure and•t is the time period studied, typically for a structure for the infrastructure the expected life span.

ETSI Methodology18

Interest rate

i

iL

1 p

ppp

pL interest rate for loanswith long durationpi inflation

i

ciL

1 p

pppp

pc increase of usefulness of the bridge i.e. increase of traffic

Inte

rest

rat

e p

Duration of loan ~30 years

ETSI Methodology19

Net present cost for a cost of value=1,0 year 0

0,01

0,10

1,00

10,00

100,00

0 5 10 15 20 25 30

Interval between MR&R actions

Cos

t

2,5%

4,0%

6,0%

8,0%

ETSI Methodology20

User cost delay

user,delay L L L Dr n0

1(1 )

(1 )

T

t t tt

L LLCC ADT N r w r w

v v r

L length of affected roadwayvr the traffic speed during bridge work activityvn the normal traffic speedADTt the average daily traffic, i.e. cars per day at time tNt the number of days of road work at time trL the amount of commercial trafficwL is the hourly time value for commercial trafficwL the hourly time value for drivers T studied time interval T

ETSI Methodology21

User costs, operation

user,operating L L G L Dr n0

1( ) (1 )

(1 )

T

t t tt

L LLCC ADT N r o o r o

v v r

New notations:oL operating cost for the commercial traffic vehiclesoG operating cost for transported goodsoD operating cost for cars T time interval

ETSI Methodology22

Societal costs, accidents and failure

society, accident r n acc0

1

(1 )

T

t t tt

LCC A A ADT N Cr

New notations:An the normal accident rate per vehicle-kilometres Ar the accident rate during roadwork Cacc the cost for each accident for the society

society, failure H,1

1

1

nj j jj

LCC K Rr

Rj probability for a specified failure coupled to KH,j. KH,j cost for failure(One value for ultimate limit state and one for serviceability limit state)For normal bridges the probability of failure is so small that it could be omitted in the analysis!

ETSI Methodology23

Valuation

Degradation models Knowledge on interest rents (100 year!!) Knowledge about the future of the traffic system!

(will the traffic increase or decrease??) Knowledge on costs for

operation, maintenance, inspection and repair

ETSI Methodology24

“Soft values” must also be included

1) Technical design

2) Investment

Valuation

Best Society benefit

3) Operation,maintenance and disposal

7) Society benefit and

lifetime

4) Society cost during main-

tenance and repair

5) Aesthetics

ETSI Methodology25

2) Investment

Valuation

6) LCA-analysisEnvironmental

issues Durable

development

Largest economic benefit and lowest

environmental disturbance

1) Technical design

4) Society cost during main-

tenance and repair

5) Aesthetics 3) Operation,maintenance and disposal

7) Society economic benefit

and lifetime

Environmental issues must also be included!

ETSI Methodology26

Parameters needed for the LCC analysis

Methodologies for dividing the bridge into different parts and giving measures of the components

Costs for construction and repair different parts of the bridge

Yearly operating costs Actions in time for MR&R actions Cost for disposal of the bridge User and societal costs

ETSI Methodology27

Suggestion for bridge

parts

Foundation

Foundation slab, plinth, pile cap

Excavation, soil

Excavation, rock

Pile

Erosion protection

Slope and embankment

Embankment, embankment end, backfill

Soil reinforcement and slope protection

Abutments and piers

All concrete structures belonging to the substructure excl. foundation

Main load-bearing structure

Slab / deck

Beam

Truss

Arch, Vault

Cable system

Pipe, Culvert

Secondary load-bearing system

Secondary load-bearing beam, cross beam

Secondary load-bearing truss, Wind bracing

Equipment

Bearing and Hinge

Edge beam

Insulation, Water proofing

Surfacing

Parapet, Railing

Expansion joint

Drainage system

ETSI Methodology28

Bridge parts and measures

Front wall (Grusskift)

Footing (-slab)(Bottenplatta)

Breast or front wall, (Frontmur)

Superstructure (Överbyggnad)

Main beam (Huvudbalk)

Substructure (Underbyggnad)

Wing wall (Vingmur)

Bridge seat (Lagerpall)

Span (Spännvidd)

Length of superstructure (Överbyggnadslängd)

Total bridge length (Bro längd)

Foundation (Grundläggning)

Backfill excl. surfacing

(Återfyllning)

0,75

m

45°

Ground contour

ETSI Methodology29

Cross-section definitions

S V GCV

Clear bridge width

Total bridge width

K

Effective bridge width

Pedestrian and bicycle path

Total bridge width

Edge beam

ParapetRailing

ETSI Methodology30

Foundation

Link or run-on slabCounterfort or buttress

Integrated back or breast wall

Base slab or footing

Expansion joint

Base slab or footing

Bearing Bearing

Embankment end

ETSI Methodology31

Materials for LCC

Material Measure Quality Description

Concrete m3 C251 Cylinder strength in MPa

Reinforcement steel ton 5002 Yield strength in MPa

Steel for pre-stressing, tendons, cables

ton 1700 Yield strength in MPa

Steel ton 3503 Yield strength in MPa

Sawn Timber m3

Glue laminated timber m3

Impregnated timber m3

Backfill soil m3

Pile m Type4 Directly coupled to the structural element

1 Example of notation. For LCC and LCA analysis an approximate value can be used. 2 Example of notation. For LCC and LCA analysis an approximate value can be used. 3 Example of notation. For LCC and LCA analysis an approximate value can be used. 4 Type of pile should be defined. Pile driving is a very energy consuming task.

OBS, LCA requires added material definitions!

ETSI Methodology32

Costs

Cost parameters should be given by the agencies hopefully in data bases updated every year!? Costs for construction Cost for MR&R actions Parameters for calculating the user costs Societal costs …

ETSI Methodology33

Definition of actions

Management Operation Inspections Repair Upgrading Final demolition and disposal

ETSI Methodology34

Operation

Management is the owners own work for keeping the bridge inventory, the planning and other actions to manage the bridge stock. Usually this work can be assigned as percentage of the actual value to re-build the bridge stock.

Operation is the yearly work to superficially and regularly inspect, clean, repair small damages of the bridges. The Swedish term is “Drift”

ETSI Methodology35

Action Frequency Aim Remark

Regular inspection Often Detect acute damages

Cleaning of the bridge

Once a year Removal of de-icing salt

Rodding of dewatering system

Once a year

Cleaning of expansion joints

Once a year

Removal of plants and bushes,…

Once a year

…

Examples of operation (yearly) actions

Examples of “operation maintenance actions”. In the Swedish system this is called “Egenskaper” or “properties”

ETSI Methodology36

Time between different MR&R actions

Needed parameters:Life spanYearly operation actionsTime interval between inspectionsTime between maintenance and

repair

ETSI Methodology37

Methods for judging time between MR&R actions

1. Mechanistic or chemical models

2. Evaluation results from large field observations,

3. The up to day most applied method is to use experience from specialists, usually people deeply involved with inspection of bridges

ETSI Methodology 38

LCC

With everything in hand it is just to calculate the LCC for a bridge or maybe all bridges in a

county or for a road network!!

ETSI Methodology 39

GOOD LUCK!

Trying and commenting our programs!