Bridges Operation management, rehabilitation and systems

Transcription

1 Bridges Operation management, rehabilitation and systems

2 2 COWI expertise Höga-Kusten Bridge, Sweden. Corrosion protection of cables. COWI services Inspection and monitoring Material technology Re-evaluation Maintenance strategies Rehabilitation and upgrading Expert services Operation management and systems Corridor studies. COWI is an internationally recognised consulting company with a leading position within bridge engineering. Operation management and rehabilitation of bridges is one of COWI s core activities. Our aim is to ensure safe operation and a long service life of your structures within reliable operation and maintenance budgets, based on the newest methods within bridge engineering. Through our highly professional and dedicated staff with a broad international experience, COWI provides professional support within all aspects of operation management and rehabilitation of bridges. Bridges Project, COWI continuously investigates and develops innovative technologies and analysis methods. ( Quality Quality is a key issue in any COWI bridge project. We operate a Quality Management System which is certified according to the requirements of ISO This assures our clients timely and professional management of any COWI project. Research and development Development of consultancy services that satisfy our customers and improvement of our staff s capabilities is an integrated and vital part of our work. Through participation in research projects, such as the EU Sustainable DS/EN ISO 9001 certificate.

3 Inspection and monitoring 3 Identification and quantification of bridge damages are of vital importance to achieve the most costeffective maintenance solution. All types of inspections and in - vestigations are carried out by COWI s highly experienced staff. The experience is based on numerous inspections of both minor bridges and major bridges, including suspension or cable-stayed bridges. Advanced monitoring systems can be provided in order to reveal deterioration of a structure at an early stage and hence significantly reduce the risk of unforeseen operation and maintenance costs. Warranty inspections can be offered to ensure that construction and rehabilitation works comply with the design specifications. Defects and deficiencies are hereby discovered at an early stage and action can be taken in due time. COWI also has extensive experience with design of access equipment for inspection of bridge girders, main cables and pylons. Damaged bridge on M5, Moscow Samara. Damage identifi cation Maintenance manual Warranty inspection Principal inspection Special inspection Cable inspection Diver inspection Corrosion sensor monitoring including humidity and potential monitoring Corrosion rate monitoring Construction monitoring Resistance monitoring Control of cathodic protection Management systems Databases for inspection results. The Great Belt East Bridge, Denmark. Inspection of main cable corrosion protection. Cathodic protection of concrete columns. Concrete investigation of column on Svendborgsund Bridge, Denmark.

4 4 Material technology Älvsborg Bridge, Sweden. Cable tests. Durability of bridges highly depends on the material properties. COWI has specialists within all fields of material technology. State-of-the-art technology is utilized for analysing concrete and steel deterioration mechanisms. Concrete technology and durability of concrete bridges is a core competence in COWI. COWI has its own concrete laboratory, where a wide variety of investigations can be carried out. Full-scale trials or special investigations are carried out to determine the condition of existing bridges. For steel bridges our experience covers standard structural steel, high-strength steel, stainless steel, wires and cables. In addition, pavement analysis can be provided for rigid, flexible, and special pavement types. On the basis of extensive experience within material investigations, our staff is able to solve the often complex correlation between material conditions, environmental issues and financial conditions. Screening for delaminations Thickness and fl aw detection Petrographic analysis Chloride content and profi le Carbonation Corrosion rate, half-cell potentials and electrical resistance Welding techniques Specifi cations for NDE Fracture mechanics Galvanic corrosion Surface treatment. Corroded hanger on Älvsborg Bridge, Sweden. Our mobile laboratory the Concrete Van contains all the equipment necessary for conducting investigations in-situ. COWI benefits from its own fully equipped laboratory for investigations and analyses, allowing us to assess the condition of a structure. The COWI Concrete Laboratory is ISO 9001 certified.

5 Re-evaluation 5 During the lifetime of a bridge it may be subject to deterioration, influencing the ability to fulfil its purpose with sufficient safety. An integrated part of a re-evaluation is therefore a condition assessment. COWI has extensive experience in condition assessment and lifetime assessment covering all kinds of materials and bridge types. COWI also covers all types of structural assessments from simple survey methods to fully 3 dimensional probabilistic analyses. The assessments may be combined with loading tests and other related test programmes. Re-evaluation, in many cases, justifies the continued use of the bridge and thus ensures the owner a significant increase in return of investment. For deteriorated major bridges the re-evaluation may be based on a rehabilitation design basis uniquely developed for the bridge in question. This involves: Actual loading conditions Calibration of partial safety factors Updating using inspection results. Such an approach facilitates implementation of a very flexible rehabilitation project by minimising traffic interruptions and inspection needs. Deterioration modelling Testing of materials Service lifetime assessment Inspection using state-of-the-art inspection techniques Optimal plans for inspection, maintenance and repair needs Structural reliability Load capacity assessment of numerous road and railway bridges. Calibration of bridge specifi c loads Calibration of safety factors Reliability updating based on inspection or test results Advanced numerical analysis Development of national guideline for probability-based assessment of bridges Chloride-induced corrosion. 3D Finite Element Model of the Little Belt Bridge 1935, Denmark, used for an upgrading. The Little Belt Bridge 1935, Denmark. Combined road and railway bridge.

6 6 Maintenance strategies Öland Bridge, Sweden. Development of optimal maintenance strategy for a 70 year period. Condition assessment including fi eld investigation Cost evaluation including maintenance, repair, replacement and road user costs Estimation of the service life Planning and scheduling the maintenance strategies Estimation of residual values of investments Cost-benefi t analysis. Major public assets such as roads and bridges need efficient management, administration and operation in order to utilise resources in an economically and technically optimal manner. Over a period of more than 20 years COWI has developed an asset management approach based on practical experience from planning, budgeting and handling of both short and long term operation, maintenance and rehabilitation works. COWI offers consultancy services for evaluation of the cost effectiveness of current bridge maintenance strategies. Calculations are carried out in fixed prices (those of the actual year for determination of the costs) with a chosen price level and a chosen discount rate. Inflation and development of wages, taxes, etc. are incorporated in the calculations by use of the price index. For an economic evaluation of alternative solutions, the most important parameters are taken into account. In addition, the evaluation of the total costs takes into account the society discount rates. There is often more than one possible method of repair. There may be several alternatives, which could be better and in the long term cheaper alternatives. To be able to compare strategies, each strategy should result in the same utility value of the structure after the maintenance. It is a prerequisite that the components are always in a functional and acceptable safety condition in all strategies and, in principle, infinitely.

7 Rehabilitation and upgrading 7 Condition and structural assessment Design of rehabilitation works Design of strengthening works Traffi c plan management Preparation of tender documents Construction supervision of the rehabilitation works. Rehabilitation may be necessary if a bridge is subject to extensive deterioration or damage, while upgrading may be required if traffic loads and/or intensity are increased. COWI performs rehabilitation or upgrading design. Necessary tasks are identified in collaboration with the client. The necessary level of detail for the investigations depends on the existing load bearing capacity and the possible need for upgrade. The analyses are tailored to each individual project ranging from deterministic calculations to reliability-based methods, including e.g. information from tests such as load tests, material strength or loading parameters. In case investigations cannot prove that the load bearing capacity is sufficient, the rehabilitation or upgrade is supplemented with necessary repair and/or strengthening. A repair or strengthening project typically includes more than one strategy in order to ensure the cost optimal solution. An important factor in determining the optimal strategy is the management of traffic plans. COWI possesses expertise within the newest methods regarding repair and strengthening, such as strengthening by carbon fibres and chloride extraction. In order to ensure sufficient load carrying capacity in all construction stages, COWI offers a construction risk analysis, which is incorporated in the evaluation of rehabilitation strategies. Rehabilitation of retaining wall along main railway in Copenhagen. Bridge deck strengthening with carbon fibre strips. Sloboda Bridge, Serbia, The bridge was bombed in 1999 during the war in the former Yugoslavia. COWI has performed a rehabilitation and a reconstruction project. Concrete core drilling. Benjamin Sheares Bridge, Singapore. COWI has provided technical assistance in inspection, condition and load capacity assessment and rehabilitation design.

8 8 Expert services Selected references: Zárate-Brazo Largo Bridges, Argentina Älvsborg Bridge, Sweden Aquitaine Bridge, France Luangwa Bridge, Zambia. Corrosion protection system for main cables COWI has unique knowledge within corrosion protection of main cables by wrapping combined with a dehumidification system. Selected references: Little Belt Bridge, Denmark Höga Kusten Bridge, Sweden Acquitaine Bridge, France. Little Belt Bridge, Denmark. Replacement of expansion joints. Corrosion protection system for steel box girders To reduce the maintenance costs for steel box girders on major bridges COWI has with great success designed and implemented dehumidification systems on many bridges. Expertise is based on projects during the last 30 years. Selected references: Little Belt Suspension Bridge, Denmark Faroe Bridges, Denmark Great Belt East Bridge, Denmark Øresund Bridge, Denmark-Sweden Stonecutters Bridge, Hong Kong Normandy Bridge, France Höga Kusten Bridge, Sweden Humber Bridge, United Kingdom. Höga Kusten Bridge, Sweden. Wrapping of main cable for corrosion protection. Replacement of cables and hangers The cables of cable-stayed and suspension bridges may suffer from corrosion, and in the worst case the cables may require replacement. COWI has experience from several cable replacement projects worldwide. Concrete technology Concrete technology has, for many years, been one of COWI s core areas of expertise. Specialists provide unique knowledge about deterioration mechanisms and modelling together with mitigating actions. Selected references: Great Belt Link, Denmark Öland Bridge, Sweden White Concrete on New Jersey elements, M3 project, Denmark.

9 9 Replacement of hanger cables on Älvsborg Bridge, Sweden. Rehabilitation design basis For deteriorated major bridges COWI has experience in developing a probability based rehabilitation design basis, which is unique for each bridge considered. Such an approach facilitates a flexible rehabilitation project minimising traffic interruptions and inspection needs. This approach was successfully applied during the rehabilitation of the Zárate-Brazo Largo Bridges, Argentina. Replacement of expansion joints COWI s multidisciplinary expertise in major bridges also covers the replacement of expansion joints. For the Little Belt Suspension Bridge, Denmark, a design basis for new expansion joints was developed using a probability based approach, including load testing and calibration of a 3D FE-model. The tailored design basis reduced the necessary dimensions resulting in cost savings. Upgrade of pile capacity COWI s expertise in reliability based assessment and soil engineering was successfully combined in an upgrade of the load bearing capacity of two large pile foundations. The results were considerable savings in strengthening costs. Selected references: Gudenå Bridge, Denmark Karlstrup Mose Bridge, Denmark Cathodic protection system Through numerous projects in Denmark and abroad COWI has obtained substantial knowledge in cathodic protection systems. COWI has the expert knowledge and the practical in-house experience necessary to evaluate and choose a cathodic protection as repair solution instead of traditional concrete repair. Karlstrup Mose Bridge. Load test on piles. Zárate-Brazo Largo Bridge, Argentina. Replacement of stay cables. Cast-in sensor to monitor the ingress of chlorides.

10 10 Operation management and systems (BMS) Inventory Principal inspection Special inspection Load capacity rating Priority ranking, where results from inspection and load capacity rating are included Maintenance strategies Short and long term budgets based on maintenance strategies and inspection results Administration of special transports, where inventory data and load capacity results are used Design of overweight permit systems adapted to national regulations, bridge rating, vehicle rating and writing of guidelines Daily administration Preparation of permissions. Overweight vehicle. Transportation of wind mill tover. COWI has more than 20 years of experience in implementing efficient management systems and computer tools, e.g. in Singapore, China, Thailand, Spain, Denmark and Uruguay. COWI s Bridge Management System (BMS) provides a rational and systematic approach in organising and carrying out activities related to bridge management and maintenance. In addition, the BMS can easily be adjusted to the specific requirements of any organisation. Educational programmes tailored for each client is part of the BMS package ensuring a successful implementation and operation. The BMS is a modular system, which secures maximum flexibility. In recent years overweight transports have increased significantly and thereby the need for efficient over-weight permit systems has also increased. The overweight permit system used in Denmark today was originally designed by COWI for the Danish Road Directorate. Since 1999 COWI has been responsible for the daily administration of the overweight permit system on the main highways in Denmark, since 2003 for the bridges in the Municipalicy and from 2009 COWI has also been responsible for road bridges owned by Danish Rail. Load test on Madum Stream Bridge, Denmark. Transport of gun barrel from 2nd world war, Denmark.

11 Corridor studies 11 A corridor study is relevant when a complete railway line or road section needs evaluation, e.g. due to an upgrade of traffic loads. The main challenges of a corridor study is to establish a well-founded basis for the decision-makers, which takes into account and integrates technical, environmental, social, and financial aspects. COWI has carried out a vast number of corridor feasibility studies in Denmark and abroad and offers in-house expertise for all aspects related to corridor studies. Preliminary identifi cation of priority actions Economic and technical studies for remedial measures Inspection and condition assessment Structural assessment Detailed fi eld investigations Traffi c surveys Cost estimates Environmental Impact Assessment Design of rehabilitation or strengtening works Preparation of pre-qualifi cation and bidding documents. Study of 200 railway bridges on the railway corridor IX in Lithuania. Corridor study of the Copenhagen - Padborg, railway line. The study included approximately 330 bridges. Study of 300 road bridges on the corridor from Sofia, Bulgaria to the Greek border. Inspection by use of climber on road bridge in Kosovo. Replacement of railway bridge on the Metropolitan Line in Copenhagen.

12 Front page: Vejlefjord Bridge, Denmark. Replacement of bridge pavement. Corrosion protection of main cable on the Little Belt Bridge, Denmark. COWI offices COWI is a leading northern European consulting group. We provide state-of-the-art services within the fields of engineering, environmental science and economics with due consideration for the environment and society. COWI is a leader within its fields because COWI s 6,000 employees are leaders within theirs. Headquarters: COWI A/S Parallelvej 2 DK-2800 Kongens Lyngby Denmark Tel.: Fax: [email protected] Internet: Contact: Operation Management, Rehabilitation and Systems, Bridges Jens Sandager Jensen Head of Department [email protected] Tel.: Erik Stoklund Larsen Chief Project Manager [email protected] Tel.: Ole Rud Hansen Chief Project Manager [email protected] Tel.: Finn Raun Gottfredsen Chief Project Manager fi [email protected] Tel.: Niels Bitsch Chief Project Manager [email protected] Tel.: Strengthening of flyover with high strength bars e-09c Printet in Denmark by Kailow