Sustainable Development in the Project Management of the Tsing Ma Bridge in Hong Kong Ir Dr Lau, C.K. Maunsell China Engineering Services Ltd. 8/F, Grand Central Plaza, Tower 2 138 Shatin Rural Committee Road Hong Kong (Former Project Director, Lautau Fixed Crossing Project Management Office, Government of HKSAR) [email protected] Abstract: A comprehensive project management system is essential for the successful completion of large civil engineering project. The paper describes the sustainable project management system adopted for the world’s longest suspension bridge carrying both road and rail traffics in Hong Kong. With mutual cooperation and partnership approach of the client and the contractors, this world class bridge contract was completed on time and within budget. Keywords: contract arrangement, site safety, quality management, environmental monitoring. Introduction The Tsing Ma Bridge connecting Tsing Yi Island and Ma Wan Island, has a main span of 1377m, and is the world’s longest suspension bridge carrying both road and railway traffic. The two anchorages are gravity structures and take the load from the main suspension cables at either end of the bridge as high as 521,000kN. The two towers of 206m high are of reinforced concrete. Each of them was slipformed in about 3 months. Total volume of concrete in towers is 46,000m3. The successful contractor has decided to adopt conventional aerial spinning method. Each cable consists of 80 strands of 368 no. 5.38mm and 11 strands of 360 no. 5.38mm galvanized high tensile steel wires. Some 28,000 tons of galvanized steel wire are required. After spinning, the wires are compacted into a circular shape approximately 1.1 metres in diameter using special cable compacting machines. The cables are then wrapped and painted. The total length of wires is 160,000km, enough to circle the earth four times. Structurally the deck section is a hybrid arrangement combining both truss and box forms and streamlined to comply with the aerodynamic requirements. A stainless steel cladding along the outer edges of the deck is provided in order to control air flow across the deck. The final external appearance is therefore of a box with faired edges having continuous gaps along the top and bottom surfaces. Internally it presents the appearance of conventional trusswork. Total steel required for the deck is 50,000 tons. Fabrication of superstructure steelwork was both in the UK and Japan on an approximately 50/50 basis. The fabricated steel works are then delivered to the assembly yard at Dong Guan, China. The completed decks unit each weighing 1,000 ton of 36m long then transported by barge to Hong Kong for erection. Sustainable Project Management The project management of the Tsing Ma Bridge was under the Lantau Fixed Crossing Project Management Office (LFCPMO) which was formed by the deployment of engineers with speciality in bridges within the Highways Department. The task of the LFCPMO was to implement the construction of these 3 large span bridges, namely Tsing Ma Bridge, Kap Shui Mun Bridge and Ting Kau Bridge on time and within budget. There are many ways in defining the term “ sustainable development “ and the mostly used definition in Hong Kong is that sustainable development in Hong Kong balances social, economic, environmental and resources needs, both for present and future generations, simultaneously achieving a vibrant economy, social programmes and a high quality environment, locally, nationally and internationally through the efforts of the community and the Government. With this in mind, the planning, design, construction, maintenance as well as the project management of the Tsing Ma bridge had been focused in the same direction. During the planning stage, there was no engineer in the Highways Department having experience in the design and construction of suspension bridge. Consequently consulting engineers were employed. For technology transfer some engineers in the LFCPMO were therefore working with the consulting engineers to set the design standard and specification for the Tsing Ma Bridge and subsequently, carried out the detailed design and contract documentation. Upon verification of the tendering exercise, the LFCPMO negotiated and signed the contract with the contractor. During bridge construction some engineers from the LFCPMO were sent to site to work with the consulting engineers in site supervision. Hence They could gain practical experience through on the job training. Therefore in the subsequent Ting Kau Bridge project, since the LFCPMO had trained sufficient engineers with sound cable supported bridge experience, the employment of consulting engineers was not required. Few years later, the in-house engineers were assigned with two large bridges, i.e. the 1,018m span Stonecutters cable stayed bridge and the 1,418m span Tsing Lung suspension bridge. During bridge construction period, the authority for making any decision was the Project Director of the LFCPMO, he had been authorized by the Employer to exercise all the rights and powers under the contract. The LFCPMO had an establishment of about 100. Half of them were professional engineers and the remainders were technical and general grade staff. One third of the LFCPMO staff were engaged in the Tsing Ma Bridge project. On site, all staff were employed by the consulting engineers for the supervision of 13 contracts including Tsing Ma Bridge, Kap Shui Mun Bridge, Tsing Yi Interchange, electrical and mechanical, traffic control and surveillance, roads and toll plaza etc. The site staff responsible for the Tsing Ma Bridge contract were about 60 and half of them were professional engineers. Their role was to act on behalf of the LFCPMO on the day to day works on site. The quality assurance and control of bridge construction site were the responsibilities of a team of resident site staff which are headed by the Engineer’s Representative (The Resident Chief Engineer). Under him, the site staff include engineers, quantity surveyors, land surveyors, inspectors, foremen, material testing team, technician and general support etc. The responsibilities of the site staff in different grade are clearly defined and checking can be carried out without blurring responsibilities. The ‘Project Administration Handbook’ and the ‘Highways Department Guidance Notes’ give clear guidelines in this respect. In order to cope with the latest development in building technology, the Highways Department organizes seminars and short courses from time to time for the site staff. They are also encouraged to attend courses organized by the tertiary institutions to obtain new knowledge and qualification for career development. When formal notice is given to the Contractor to commence work, the Contractor must be required to take in charge of the site and be responsible for its care and control. The Contractor should immediately provide the name and qualification of the Site Agent for approval. He is also required to submit a programme of works showing how he proposes to carry out the works. For complex project like Tsing Ma Bridge the programme should be in the form of a network analysis showing the critical path. A progress chart has been maintained on site and brought up to date to compare with the programme. Any delay must be rectified immediately. A site diary is kept on site and the site foreman will enter the diary to record the progress of the works, any occurrences which might affect the progress and quality of the work and number and types of labourers and plant on site. The diary should be signed daily by the Inspector and the Site Agent for future reference in case of dispute. The resident engineer checks and initials the site diary at least once a week. Site instructions will be given to the contractor in the standard site instruction form. The original should be handed to the site agent who then acknowledges receipt on the duplicate for the record of the resident engineer. Site measurements will be entered in accordance with the method of measurement adopted for the contract. Entries should be made by supervisory staff and signed by authorized representatives of both the Contractor and the Engineer. The Contractor will submit monthly statement showing the estimated contract value of the permanent work executed up to the end of the month for the issue of an interim payment certificate. The resident engineer should check and sign the statement, making such alterations as he considers necessary in ink. The resident engineer then will make recommendation to LFCPMO for payment. The resident engineer also submits progress photographs and progress report indicating physical progress on ground and expenditure progress to the Chief Engineer. Any problem which causes, or is likely to cause delays, should be reported together with the action being taken to overcome it. In case of contractual disputes, the matters would be dealt with in accordance with the contract. For effective management of the contract, the LFCPMO delegated some of the Employer’s power to the Employer’s Representative, such as the issue of amended working drawings to suit site condition, alignment survey, approval to site safety and precaution plan and procedure, filling in diary, responsible and approval of the material quality control and testings, quality plan, repair to defective works, order to suspend work due to safety reason, variation (increase or decrease) to works details and quantity (not exceeding HK$300,000), keep works record, certification of contract payments etc. However, the LFCPMO retained the power on major issues of which approval from the Project Director was required. Examples were, the commencement and completion of maintenance period, the approval of contractor’s sub-contractor, approval of works programme and extension of time, order to accelerate works, certification of completion of works, variation (increase or decrease) works details and quantity (exceeding HK$300,000), order to stop part of the work or whole of the work on site, and negotiation and settlement of claims and contractual matters etc. Contract Arrangement Traditionally, the civil engineering contracts in Hong Kong follow the format of the Institution of Civil Engineers, UK and plus some modifications to suit Hong Kong conditions. In order to avoid the possibility of above budget and to ensure the completion of contract on time, the contract document for the Tsing Ma Bridge included some special conditions and made some modifications to enable that the Employer had more effective control on the cost and progress, and encouraged the contractor to construct the bridge in accordance with the programme. The special conditions are as described below : Under the conventional contract, the contractor will be paid in accordance with the amount of completed work, normally measured monthly. If the contractor has completed 100cu.m of earth work at the end of a particular month, he will be paid for by multiplying the 100m3 with its corresponding rate in the bill of quantities. However, the Tsing Ma Bridge contract payment was made in accordance with the predetermined programme, the mile-stone payment schedule. In the document, every activities such as foundation, tower, bridge deck, anchorages etc had programme schedules. For example, the foundation should be completed 12 months after the commencement of contract, the first month should complete 5%, the second month 12%, third month 20% and so on. During tendering stage, the respective tenderers, should decide to amend or not to amend the schedules in the contract after considering his own programme, method of construction and plant and labour resources. Once the contract was signed, both sides should honour the schedules in the contract that had legal implications. After the commencement of the contract, if the contractor was able to complete 5% of the foundation index, he would be entitled to the corresponding payment. However, if he only achieved 4%, he would not be entitled to any payment as he did not achieve the mile stone. On the other hand, if he could achieve 6%, he would only be paid for 5% in accordance with the schedule. Therefore the contrator had worked hard to the programme in order to obtain the payment and gain the profit as scheduled. The Employer also had a timetable for programmed financial arrangement and payment schedule so that appropriate application could be made for better financial control. Another special feature of the form of the contract is Fixed Price Lump Sum Contract, that means the contract price will not be adjusted in accordance with the material and labour fluctuations index. Once the contract was signed, the contract sum is fixed and will not be adjusted according to inflation, hence the contract sum at the completion date is the same as that at the commencement date. In order words, the unit prices in the contractors’ tenders are deemed to include the material and labour fluctuation for the duration of the contract. The contractor therefore should have forward planning to place order with the overseas manufacturers and material suppliers for the required material so as to reduce the risk of price fluctuations. Contract also specifies, there will be no extension of time due to inclement weather and typhoon. The contract allows the contractor for the importation of labour to minimize the effect of insufficient labour in Hong Kong. This kind of fixed price lump sum contract had been introduced into Hong Kong for the Mass Transit Railway projects and some large private building development projects and the results have been good. Such kind of contract arrangement would ensure that the construction cost would not exceed the budget and the contract would be completed on time. The other conditions in the contract are basically the same as for the conventional contracts. Say, the Performance Bond is 10% of the contract sum. If the performance of the contractor had been very bad and the progress was very poor, the Employer could re-enter the site and re-tender to find another contractor to complete the outstanding work. Consequently, the Performance Bond will be cashed by the Employer. Because the Tsing Ma Bridge is the one and only one route to the new airport, the general public and the society will suffer great loss if the bridge was not able to complete on time. For this reason, the amount of liquidated damage is huge to account for society losses. For the period of the first 30 days, the penalty is HK$1,350,000 per day. For the subsequent period, the penalty is increased to HK$3,450,000 per day. However the cap figure is limited to HK$900,000,000. At the end of 1990, invitation letters for the Express of Interest were sent to prospective and reputable bridge contractors worldwide. They were requested to submit documents about their experience, finance and resources. 11 international joint ventures expressed their interest with relevant documents and information. Only 5 JV passed the pre-qualification exercise. On 31 July 1991, the Highways Department sent them the tender document and invited them to submit tenders for the construction of Tsing Ma Bridge. Subsequently, one JV was disqualified due to the withdrawal of one major partner. The tender was closed on 16 December 1991. The contract was let in May 1992 for a contract period of 5 years on a fixed price lump sum basis at HK$7100 million. Contract was subsequently completed in May 1997. Site Safety and Quality Assurance In the construction of the Tsing Ma Bridge, lots of activities were either at height or below sea level, much more difficult than normal civil engineering contracts, therefore, special consideration was given to site safety measures. Contract specified that the contractor should employ one safety officer responsible for safety measures for every 200 workers on site. The contractor should organize safety seminars and training courses to workers at regular intervals. One Senior Engineer under the Chief Engineer was assigned to supervise site safety issues, to hold monthly site safety management committee meeting, to have discussions at working level, and to review the implementation programme of the safety plan etc. The contractor would be rewarded if the safety record for that month was good. But, if there had been bad safety record for few consecutive months, and many injuries on site, the contractor would be penalized. For severe case, the contractor would be suspended for tendering Government contracts. In order to ensure the Tsing Ma Bridge contract had quality control, LFCPMO specified that the tenderers should include a comprehensive Quality Plan to implement full quality management and quality assurance method. The Quality Plan should be prepared in accordance with the international quality inspection standard ISO 9001 and should comprise of Management Quality Plan, Manufacturing Quality Plan and Construction & Installation Quality Plan. The contents were prepared to aim at design, selection of material and various activities under construction. Every step in the plan must be audited by an independent auditor to ensure correct quality assurance procedure. The Tsing Ma Bridge contract specifications describe the quality of material, construction sequence and workmanship required. The bridge structure is designed on the basis that these will be met. The General Specification for Civil Engineering Works is the standard Specification and lays down the quality of materials, the standards of workmanship, the testing methods and the acceptances criteria for civil engineering works undertaken for the Hong Kong SAR Government. Materials and components prefabricated off site will have to meet the specified standards. In most cases, it would be sufficient to rely on the manufacturers test certificates. Many components for the Tsing Ma Bridge were made overseas, e.g. the bridge deck component were fabricated in the UK and Japan, saddles, wires for main cable were manufactured in the UK, the stainless claddings to bridge deck were made in Australia etc. In order to ensure the quality of components had met the required standard before dispatched to Hong Kong, the LFCPMO employed local independent checking firm to have random inspections and check at the place of manufacture. Spot checks may be made if necessary. The routine material testings were carried out by the Public Works Central Laboratory of the Hong Kong SAR Government. Other accredited material tasting laboratories, such as Hong Kong Universities, private testing firms were also qualified to carry out such testings. Sometimes, it was required to perform full scale loading test on bridge structures or components to see whether they had reached the design requirements. For large and complicated bridge bearing loading tests, there was no suitable testing facilities in Hong Kong, the testings were carried out in overseas under the supervision of a qualified witness. Inadequate or unsuitable temporary works or erection procedure may result in failure and could cause injury to workers or damage to permanent work and hence affect or reduce the useful life of the bridge structure. Under the contract, the Contractor was responsible for the design and stability of all temporary works. The Contractor was required to employ an Independent Checking Engineer to check and to certify that the design complies with the contractual requirements. The Independent Checking Engineer should be a professionally qualified engineer independent of the Contractor and not associated with the design of the Temporary Works. Environmental Monitoring and Audit An environmental impact assessment for the project was carried out during the design stage. The report identified areas of concern in the construction stage, hence acceptable mitigation measures were incorporated into the contract document for the compliance of the contractor. A special team was assigned on site to carry out compliance monitoring and to assess the performance of the construction activities in environmental terms against the established baseline. Contractor’s works were audited in respect of landscape, noise, air pollution, waste arisings and water quality impacts. Where significant adverse environmental impacts were identified, the contractor would be instruct to take necessary remedial measures. Conclusion The world class Tsing Ma Bridge has been able to be completed on time, within budget and with high standard, it is really a world record. That depends on a comprehensive and sustainable project management system. To make this system successful, it is the intense effort put in by everyone, because all of them recognize the importance of the project management system and have strong commitment to implement the system. Adequate and clear definition of responsibilities and guidelines are essential to them for the successful implementation of the system. The Tsing Ma Bridge with a main span of 1377m was completed in May 1997. The graceful Tsing Ma Bridge has become a new landmark for Hong Kong in symbolized with the Golden Gate Bridge in the San Francisco. Elevation Cross-section Tsing Ma Bridge Kap Shui Mun Bridge Ting Kau Bridge Tsing Lung Bridge Stonecutters Bridge