國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Civil Engineering- Historical Context -

Hsin-yu Shan

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Modern Date

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Monuments of the Millennium

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

As we entered the new millennium, the American Society of Civil Engineers (ASCE) initiated programs to reflect on the contributions of the profession to the development of quality of life in the 20th century.For the Millennium Challenge, ASCE canvassed its members in late 1999 to determine the 10 civil engineering achievements that had the greatest positive impact on life in the 20th century. Rather than individual projects, they chose to recognize broad categories of achievements.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Monuments of the Millennium

Airport Design And DevelopmentKansai International Airport

DamsHoover Dam

The Interstate Highway SystemLong-Span Bridges

Golden Gate Bridge Rail Transportation

Eurotunnel Rail System

Kansai International Airport

Hoover Dam

Golden Gate Bridge

When the bridge opened in 1937, with a main suspension span length of 4,200 feet, it was the longest in the world. The engineering obstacles poised by the mile-wide, turbulent Golden Gate Strait led engineers to devise a bridge that required four years to build, 83,000 tons of steel, 389,000 cubic yards of concrete, and enough cable to encircle the earth three times.

Previous ASCE designations for the Golden Gate Bridge include: the National Civil Engineering Landmark (1984) and Seven Wonders of the World (1955). Other significant bridges include the Verrazano-Narrows Bridge, the George Washington Bridge, the AkashiKaikyo (Japan) and the Humber Bridge (England).

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Sanitary Landfills/Solid Waste DisposalSkyscrapers

The Empire State Building Wastewater Treatment

Chicago Wastewater System Water Supply and Distribution

The California Water Project Water Transportation

The Panama Canal

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Iron and Steel

The Iron Age came about approximately 3500 years ago (1500 B.C.), when a Hittite inventor in what is now eastern Asia developed methods of smelting iron, and alloying it with carbon to create steel, and then forging the new metal into tools. It was iron and steel tools which made possible the fabulous cultures of Greece and Rome.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Steel and the SkyscraperHenry Bessemer (1813-1898) is the man whose name we associate today with one of the major processes of producing steel. It was Bessemerʹs discovery of a process for making steel cheaply which led to its use in the construction industry.George A. Fuller (1851-1900), as a young man, was employed in his uncleʹs architectural office, drawing building plans. He soon became interested in the problem of load bearing capacities and how much weight each part of a building would carry. During the 1880s he went to Chicago and set up business as a building contractor, where his firm built the Tacoma Building in1889. This was the first structure ever built in which the outer wallscarried no burden and served no purpose other than to keep out the elements and provide a cosmetic facade.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Eventually Fuller and an architect, Daniel Bumham, were called to New York to design and build an office building on a small triangular plot of land in downtown Manhattan. Fuller told the land owners that he could construct a 21 story building, which was twice the height that he could achieve if they limited him to conventional materials, such as stone or brick. The building weight would rest on Bessemer steel beams, which would be riveted together in the form of cages, thus tying the whole building together. Despite great public skepticism that winds would blow the walls in or bend the steel cages, the Flatiron Building at the corner of Broadway and 23rd was one of New Yorkʹs first skyscrapers in 1902. Once George Fuller and the construction firm he created paved the way, others followed and today about half of all the large apartments and office buildings in this country are built on his steel cage system.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Structural height508 m (1667 ft)Height to roof448 m (1470 ft)Height to top floor438 m (1437 ft)Floors 101TopoutOctober 17, 2003OpeningDecember 31, 2004Gross floor area450,000m²380 piles @80 m

A 660-ton tuned mass damper is held at the 88th floor, stabilizing the tower against earthquakes, typhoons, and wind. The damper can reduce up to 40% of the tower's movements.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Taipei 101 has 101 stories above ground (hence the name) and five under ground.

The building holds the records for:Ground to structural top: 508 m (1667 ft), a record formerly held by the Petronas Twin Towers at 452 m (1483ft). Ground to roof: 448 m (1470 ft). Formerly held by the Sears Tower (442 m = 1454ft) Ground to highest occupied floor: 438 m (1437 ft). Formerly held by the Sears Tower.

It does not hold the record forGround to pinnacle, which is held by the Sears Tower 529 m(1703ft).

Chicago Wastewater System

The California Water Project

Conceived more than 50 years ago with bold imagination by engineers of dedication and courage, a system of aqueducts, dams, reservoirs and plants meets the water resources needs of two-thirds of California's population serving more than 23 million citizens and thousands of businesses daily.

Features of the project include 32 storage facilities, reservoirs and lakes, 17 pumping plants, three pumping-generating plants, five hydroelectric power plants, and 660 miles of open canals and pipelines.

The Panama Canal

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Seven Wonders of the Modern World

1996

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

As a tribute to modern societyʹs ability to achieve the unachievable, reach unreachable heights, and scorn the notion of ʺit canʹt be done,ʺ in 1994 ASCE sought nominations from across the globe for the Seven Wonders of the Modern World. The chosen projects pay tribute to the greatest civil engineering achievements of the 20th century.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

The Seven Wonders of the Modern World: Channel TunnelCN TowerEmpire State BuildingGolden Gate BridgeItaipu DamNetherlands North Sea Protection WorksPanama Canal

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Channel Tunnel

The 31-mile Channel Tunnel (Chunnel) fulfilled a centuries-old dream by linking Britain and the rest of Europe. Three 5-feet thick concrete tubes plunge into the earth at Coquelles, France, and burrow through the chalky basement of the English Channel.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

The $15 billion Channel Tunnel makes the old dream of a ground link between Great Britain and continental Europe a reality for the first time since the Ice Ages.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Through two of the tubes rush the broadest trains ever built. The double decker behemoths, which span 14-feet across, traverse the tunnel at close to 100 mph. Maintenance and emergency vehicles utilize the third tunnel, located between the rail tubes.Huge pistons open and close ducts, relieving the pressure that builds ahead of the trainsʹ noses.Some 300 miles of cold water piping run alongside the rail tracks to drain off the heat raised by the air friction.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Project launchMarch 1985 British & French governments initiate Fixed Link consultation20 January 1986Eurotunnel selected from a short list of four Fixed Link projects12 February 1986Signing of Franco-British ‘Treaty of Canterbury’14 March 1986Signing of the ‘Concession Agreement’29 July 1987Ratification of the ‘Treaty’; ‘Railway Usage Contract’ signed

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Construction15 December 1987Tunnelling begins1 December 1990 First breakthrough, 22.3km from Britain/15.6km from France28 June 1991Tunnelling completed (150km of tunnels dug in 3_ years)10 December 1993TML deliver the project to Eurotunnel1993-1994 Completion of fitting-out and testing of the system

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Operation6 May 1994Official inauguration by Queen Elizabeth II & François Mitterrand19 May 1994Eurotunnel starts Truck Shuttle service1 June 1994 First rail freight train travels through the Tunnel14 November 1994Eurostar starts commercial services22 December 1994Passenger Shuttle service for cars starts26 June 1995 Passenger Shuttle service for coaches starts

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

1 July 1997British/French Governments extend concession to 208613 April 1999On-line booking introduced on www.eurotunnel.com30 June 1999Eurotunnel is awarded ISO 9002 quality certification5 January 2000 Under Concession rules, plans for second Fixed Link submitted5 September 2000 Eurotunnel offers six truck shuttle departures per hour13 February 2003Licence to operate trains in France under new EU liberalisation rules

The Channel Tunnel terminal at Cheritonnear Folkston in Kent, from the Pilgrims' Way on the escarpment on the southern edge of Cheriton Hill, part of the North Downs.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

PlanningIn 1957 le Tunnel sous la Manche Study Group was formed. It reported in 1960 and recommended two main railway tunnels and a smaller service tunnel. The project was launched in 1973 but folded due to financial problems in 1975 after the construction of a 250 m test tunnel.In 1984 the idea was relaunched with a joint United Kingdom and Frenchgovernment request for proposals to build a privately funded link. Of the four submissions received, the one most closely resembling the 1973 plan was chosen and announced on 20 January 1986. The Fixed Link Treaty was signed by the two governments in Canterbury, Kent on 12 February 1986and ratified in 1987.The planned route of the tunnel took it from Calais to Folkestone (a route rather longer than the shortest possible crossing) and the tunnel was to follow a single chalk stratum, which meant the tunnel was deeper than the previous attempt. For much of its route, the tunnel is nearly 40 m (130 ft) under the seafloor, with the southern section being deeper than the northern.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

ConstructionDigging the tunnel took 15,000 workers over seven years, with tunnelling operations conducted simultaneously from both ends. The prime contractor for the construction was the Anglo-French TransManche Link, a consortium of ten construction companies and five banks of the two countries. Engineers used large tunnel boring machines (TBMs), mobile excavation factories that combined drilling, material removal, and the process of shoring up the soft and permeable tunnel walls with a concrete liner. After the British and French TBMs had met near the middle, the French TBM was dismantled while the British one was diverted into the rock and abandoned. Almost 4 million m³ of chalk were excavated on the English side, much of which was dumped below Shakespeare Cliff near Folkestone to reclaim 90 acres (360,000 m²) of land from the sea.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Tunnels, Terminals & Technology The tunnels are 50 kilometres long and 30 metres apart and were bored in the rock strata under the Channel at an average depth of 45 metres below the seabed.The two large tunnels ( 7.6 metres diameter) each contain a single track railway line. The smaller service tunnel ( 4.8 metres diameter) is located between the two rail tunnels and is equipped with a wire guidance systemfor specially designed service tunnel vehicles.All three tunnels are connected every 375 metres by a cross-passage which gives access to the service tunnel in case of emergency. The cross-passages are also used for ventilation and maintenance service access. Every 200 metres, the two rail tunnels are linked by piston relief ducts. These are used for the regulation of the air pressure in the tunnels.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Geology & Surveying UK FRANCE Shakespeare Cliff / SangatteUndersea crossovers / rock strata — chalk / chalk marl / gault clay depth beneath seabed — average 25-45 metresSatellite data from geophysical surveys provided information about the geology and helped to determine the alignment and route of the tunnel.To maximise the favourable ground conditions, the tunnels were excavated in the layer of chalk marl except for a 3 kilometer section on the French side.

NUMBER OF DRIVES ( tunnels excavated )12 - 6 undersea, 6 underland

NUMBER OF TBMS11 - 6 undersea, 5 underland

( a French machine bored 2 underland tunnels)

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Dates of Breakthroughs:Undersea service tunnel - 1st December 1990Undersea rail tunnel north - 22May 1991Undersea rail tunnel south - 28 June 1991

Date Tunneling Commenced:1st December 1987

Finished Tunnel Diameter:Rail tunnels 7.6mService tunnel 4.8m

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Completion 1 December 1990The British and French efforts, which had been guided by laser surveying methods, met with less than 20 mm of error.The tunnel was officially opened by Queen Elizabeth II and French President François Mitterrand in a ceremony held in Calais on 6 May 1994.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

StatisticsThe Channel Tunnel is 50 km (31 miles) long, of which 39 km (24 miles) are undersea. The average depth is 45 m (150 ft) underneath the seabed. It opened for business in late 1994, offering two principal services: a shuttle run for vehicles, and the Eurostar passenger service linking London with Paris and Brussels.In 2004, 7,276,675 passengers travelled through the tunnel on Eurostarwhile in the same year Eurotunnel carried 2,101,323 cars, 1,281,207 trucks, and 63,467 coaches on its shuttle trains.Rail freight carried through the Channel Tunnel increased by 8% to 1,889,175 t in 2004.A journey through the tunnel lasts about 20 minutes; from start to end, including a large loop to turn the train round, a shuttle train journey totals about 35 minutes. Eurostar trains travel considerably more slowly than their top speed while going through the tunnel, in part to fit in with the shuttle trains.At completion, it was estimated that the whole project cost around £10 billion.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Operation The tunnel is operated by Eurotunnel plc. Four types of train services operate:Eurostar, a high speed passenger service. This connects Londonʹs Waterloo station (named for the Napoleonic battle between the UK and France) with the Gare du Nord station in Paris and with Brussels Midi/Zuid station, with stops at Ashford, Calais-Frethun and Lille. All Eurostar services will switch from Waterloo to St Pancras railway station when the new Channel Tunnel Rail Link railway line is completed between the tunnel and London in 2007. Eurotunnel Shuttle, a rail ferry service. These carry cars, coaches and vans between Sangatte (Calais/Coquelles) and Folkestone. Enclosed rail wagons with minor amenities, some double-deck, permit drive-on and drive-off operation; passengers stay with their vehicle. Formerly marketed as Le Shuttle. Eurotunnel freight shuttle trains. These carry lorries on open rail wagons, with the lorry drivers travelling in separate passenger coaches. Rail freight service. These trains carry conventional rail freight or containerloads between a special transfer yard in France to destinations in England.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Eurostar trains travel at high speeds in France, where the tracks are modern and custom-made for the standard TGV cruising speed of 300 km/h (186 mph), and within the tunnel at up to 160 km/h (100 mph), their speed in Kent once they leave the Channel Tunnel Rail Link is limited by the relatively low-speed tracks over which they must run. The project, a partly government-funded scheme to build a dedicated high-speed line from London to the tunnel entrance, is expected to be completed in 2007. The first stage of the link, running from the tunnel to North Kent, was opened in 2003.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

SovereigntyAs one of the first international rail tunnels, the Channel Tunnel required inventive approach to border controls. The official border between France and the United Kingdom is a painted line roughly halfway through the tunnel (there is more tunnel on the UK side).

The English half is part of the District of Dover and the county of Kent. As a practical matter border controls are handled at boarding or on the train. A detailed three-way treaty between the United Kingdom, France, and Belgium governs border controls, with the establishment of control zones wherein the officers of the other nation may exercise limited customs and law enforcement powers. For most purposes these are at either end of the tunnel; for certain city-to-city trains the train itself represents a control zone.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Summary traffic information

2,865,2512,947,3882,447,4321,463,580 1,743,6861,889,175 Rail freight tonnes

6,593,2477,130,4176,947,1356,602,8176,314,7957,276,675Eurostarpassengers

82,07479,46075,40271,91171,94263,467Coaches

838,7761,133,1461,197,7711,231,1001,284,8751,281,207Trucks

3,260,1662,784,4932,529,7572,335,6252,278,9992,101,323Cars

199920002001200220032004

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

CN TowerThe worldʹs tallest free-standing structure soars 1,815-feet above the sidewalks of Toronto, three times the height of its better-known cousin, the Seattle Space Needle. Today the tower is off by a mere 1.1-inch. Designed with the aid of a wind tunnel, the CN Tower can withstand 260-mph gusts.The SkyPod, a seven-story structure, 1,100-feet high, was built around the base of the tower and jacked into place as one unit.A pair of 10-ton counterweights is attached to the mast to keep the tower from swaying too much.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Empire State BuildingMeasuring 1,250-feet high, the Empire State Building is the best-known skyscraper in the world, and was by far the tallest building in the world for more than 40 years. Construction was completed in only a year and 45 days, without requiring overtime.Ironworkers set a fervent pace, riveting the 58,000-ton frame together in 23 weeks.Just below them, plumbers laid 51 miles of pipe, electricians installed 17-million ft. of telephone wire and masons finished the exterior in only eight months.

The building was so well engineered that, in 1945, it was easilyrepaired after a B-25 twin-engine bomber plane crashed into it in the dense fog. The precise choreography of the project revolutionized the tall building construction industry. Although it has been surpassed as the world's tallest building, the Empire StateBuilding remains the standard against which all other skyscrapers have been judged for the last 65 years.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Golden Gate BridgeMore than 66 years after its completion, the Golden Gate Bridge, once the worldʹs longest and tallest suspension bridge, stands at the entrance of the San Francisco Bay as a beloved international icon. Hanging from two 746-foot-high towers, the bridge is suspended by two massive main cables that contain 80,000 miles of wire and measure one yard in diameter. In fact, the Golden Gate Bridge cables contain enough wire to encircle the earth three times.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

To leap across the mouth of an ocean harbor, something never before accomplished, civil engineers planted one pier in the open sea, 1,100-feet from the shore. Construction crews braved biting cold, 70-mph gusts and dizzying heights to complete the bridge in only four years. It survived the 1989 Loma Prieta earthquake suffering no damage, and in 66 years the bridge has only been shut briefly (longest closure was 3 hours and 27 minutes) to traffic three times due to periods of high sustaining winds. A $400 million seismic retrofit, which will allow the bridge to withstand a nearby earthquake that measures 8.3 on the Richter scale, began in August 1997.

20 Construction Views of the Golden Gate Bridge

1933-1936

20 Construction Views of the Golden Gate Bridge

1933-1936

Pictures will automatically advance every 10 secondsPictures will automatically advance every 10 seconds

©1999 Gladys Cox Hansen

Prepared by Prepared by the Museum of the City of San Franciscothe Museum of the City of San Francisco

©©1999 Gladys Cox Hansen1999 Gladys Cox Hansen

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Itaipu DamFive-miles-wide and requiring enough concrete to build five Hoover Dams, the Itaipu Dam spans the Parana River at the Brazil/Paraguay border. During its construction, workers shifted the course of the seventh largest river in the world by digging a 1.3-mile bypass. To accomplish this they had to remove 50 million tons of earth and rock. The main dam, as high as a 65-story building, is composed of hollow concrete segments; while the flanking wings are earth androck fill. Its powerhouse measures one-half-mile long and contains 18 hydroelectric generators, each 53-feet across. Some 160-tons of water-per-second pour onto each turbine, generating 12,600-megawatts, enough to power most of California. Itaipu supplies 28 percent of all the electric energy in Brazilʹs south, southeast and central-west regions, and 72 percent of Paraguayʹs total energy consumption.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

FactsConstruction started in January 1975 and finished in 1982. It took 30,000 people 7 years to build the Itaipu Dam.It cost $20 billion to build. The dam supplies electricity to Brazil and Paraguay. The dam is 7.76 kilometres long and 196 metres high. The reservoir behind the dam has an area of 1350 square kilometres. It is a hollow gravity type dam. The Itaipu Dam generates 75 billion kilowatts of electricity per year.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Netherlands North Sea Protection Works

This singularly unique, vast and complex system of dams, floodgates, storm surge barriers and other engineered works literally allows the Netherlands to existThe North Sea Protection Works exemplifies the ability of humanity to exist side-by-side with the forces of nature.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

The North Sea Protection Works consists of two monumental steps the Dutch took to win their struggle to hold back the sea.

Step one, a 19-mile-long enclosure dam, was built between 1927 and 1932. The immense dike, 100-yards thick at the waterline, collars the neck of the estuary once known as Zuiderzee. Step two, the Delta Project, was intended to control the treacherous area where the mouths of the Meuseand Rhine Rivers break into a delta. The projectʹs crowning touch was the Eastern Schelde Barrier, a two-mile barrier of tell gates slung between massive concrete piers, which fall only when storm-waters threaten.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

The crown on this giant flood-control project is the barrier dam that stretches 1.75 miles across the three channels of the Eastern Schelde. This dam consists of several strings of gates and their massive supporting piers which, in normal weather, allow tidal seawaters to ebb and flow in the Eastern Schelde estuary, thus benefiting the fish and bird life and the local fisheries.

The Oosterschelde storm surge barrier

Bottom consolidation

The piers The piers were the most important elements of the dam. They were produced in a building excavation with a surface area of about one square kilometre, located 15.2 metres below sea level. A ring-dike kept the sea water outside the excavation. The dry dock consisted of four parts. When the piers of one part were finished, this part would be flooded. The lifting ship then sailed into the dock, lifted the heavy pier and shipped it off to its place in the barrier. Each pier consisted of 7,000 cubic metreof concrete. Therefore, the dock may also be typified as a large concrete factory in which 450,000 cubic metre of concrete was manufactured between 1979 and 1983.

The construction of each pier almost took one and a half years. One started building a new pier every two weeks. This way, thirty piers were in production at the same time. It took an enormous amount of organisationand planning to finish the giant and complex structures in time. People worked day and night, because otherwise the concrete could not harden properly. The sixty-five piers were each between 30.25 and 38.75 metres high and weighed 18,000 tonnes. Two extra piers were built, for safety’s sake. Visitors of Neeltje Jans, the former artificial island, can now climb one of these left-over piers.

The placement

When all the piers were finished, the building excavation in which they were built, was flooded. Two ships took the piers to the right place. The ship Ostrea could lift the piers one by one and sailed them to a floating pontoon. This pontoon marked the place where the pier should be sunk.

Slides When the piers stood firmly on the bottom of the Oosterschelde, the construction of the barrier could be finished. The piers were raised with the top-pieces, upon which the slides were fixed. Hollow tubes were placed on the piers, and on top of this came a road. The tubes provided room for the equipment responsible for making the slides move.

Mytilus (mussel)

This ship made sure that the bottom of the Oosterschelde was compressed along the section were the barrier would be built. When the bottom is compressed, the sand and clay parts are compacted more closely to each other. The bottom becomes more solid.

Without the work of the Mytilus, the barrier would not have been as firm. The entire compression process took place under water and continued twenty-four hours per day. The needles transferred vibrations to the sea bottom, with a frequency of between 25 and 30 Hertz and an amplitude of 4 to 5 millimetres.

Cardium (cockle)

Although the Ostrea was the most impressive ship of the fleet, the Cardium was the most expensive one. The Cardium carried out an important task: putting down the mats. These mats which were thirty-six centimetres thick, forty-two metres wide and two hundred metres long. The synthetic mats were filled with sand and gravel in a factory. The mats were put on the sea bottom at a rate of ten metres every hour. An extra mat was put at the areas where the piers were to be placed. This was to protect themats against wear, which could be developed through the opening and closure of the slides.

The Ostrea (oyster)

The Ostrea was the flagship of the Delta fleet. With its length of eighty-seven metres, the typical U-shape and a capability of 8,000 horsepower, it was the most impressive ship. The ship lifted the piers from the dry dock and sailed them to the place of the barrier. With the open side of the ‘U’, the ship manoeuvredaround the pier.

The ship could steer easily, thanks to its four screw propellers. On both sides there were two porches fifty metres high. The piers were fixed to these porches. The porches could not lift more than 10,000 tonnes however, whereas the piers weighed 18,000 tonnes. So how did the Ostrea put the piers in the right place? Fortunately, the levers did not have to lift the piers completely out of the water. The most important factor was that they did not touch the bottom of the sea during transportation. Because of the upward pressure of the water, the levers needed to provide less power.

Macoma (nun)

This pontoon, named after a shellfish, was situated exactly in front of the place where a pier would be placed. When the Ostrea had taken a pier, it moored against the Macoma. To offer the Ostrea some stability, the pontoon had a coupling mechanism with a power of six hundred tonnes. The Macoma also had a second function: an enormous vacuum cleaner was used to ensure there was no sand between the pier and the bottom. This was an extremely difficult job, because the tidal movements moved large amounts of sand each day.

Another ship, the Jan Heijmans, helped the Cardium place the mattresses. The Jan Heijmans was also responsible for the filling of the holes between the mattresses and the gravel. The Macoma worked together with the Sepia and the Donax I during the placement of gravel ballast mats on the bottom.

Maeslant barrier

The most important demand for the design was that the barrier should not hinder the shipping. The barrier should only be closed under exceptional circumstances - no more than once or twice every ten years. In 1991, four years after the competition was held, construction started. Which design had won? Out of six submissions, the design of the Building Combination MaeslantBarrier won. The Maeslant barrier would consist of two steel doors which could be sunk down and could be turned away in the docks in the shores.

BOS and BESThe Maeslantkering is operated by a computer. In the case of a storm flood, the decision of whether or not to close the barrier is left to a computer system (BOS). The chance of mistakes is greatly increased if people were to make the decision. A computer will only follow predefined procedures, it doesn’t get its own ideas and it is not affected by poor environmental conditions. The system only takes into account the water and weather forecasts. On that basis it calculates the expected water levels in Rotterdam, Dordrecht and Spijkenisse. When the BOS decides to close the barrier, it gives orders to another computer system, the BES. The BES carries out the orders of the BOS. The system operates entirely automatically, but remains under constant human supervision with regards to the procedures.

Movement works

The movement works are operated from control buildings at the north and south side. The movement works consist of three parts: the dock gate, the locomotive and the ballast system of the retaining wall. The dock gate opens when the barrier is activated. The barrier is driven into the New Waterway by the locomotive. The ballast system allows the barrier to sink.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Panama CanalThe dream of Spanish conquistadors and the failed ambition of famed French canal builder Ferdinand de Lesseps, the Panama Canal is one of civil engineeringʹs greatest triumphs. Under the direction of U.S. Col. George Washington Goethals, 42,000 workers dredged, blasted and excavated the path stretching from Colon to Balboa. They moved enough earth and rubble to bury the island of Manhattan to a depth of 12-feet, or enough to open a 16-foot-wide tunnel to the center of the Earth. The canal was finished on time and within budget.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Despite this, after completion a challenge remained: How to tame the flood waters of the Chagres River, known to rise 25-feet in a single day during monsoon season? The engineersʹ solution was to erect a dam that, at the time, formed the worldʹs largest man-made lake. The Canal operates as regularly today as it did in 1914. In each transit, 52 million gallons of fresh water is lost, but quickly replaced by Panamaʹs heavy rainfall. The canal remains a testament to the combined skills of structural, geotechnical, hydraulic and sanitary engineers.

國立交通大學土木工程學系 Dept. of Civil Engineering, NCTU

Conclusions