[ Copyright © 2017 American Society ofCivilEngineers. All rights reserved. A Greater Wonder 48 ]

Civil Engineering waterway, eachwithaseries The Canalexpansion complexes ontheAtlantic project features newlock of water-saving basins. and Pacific sidesofthe JUNE

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COURTESY OF THE AUTHORITY expansion project has also sent infrastructure expansion projecthasalsosentinfrastructure improvement ripples aroundtheglobe. canal can accommodate. The $5.25-billion canal canaccommodate.The$5.25-billion and increased the size of vessels that the and increasedthesizeofvesselsthat has doubledthewaterway’s capacity the Panama Canal now has a third the PanamaCanalnowhasathird lane with its own set of locks that lane withitsownsetoflocksthat By Robert L. Reid eighth wonder of the world, eighth wonderoftheworld, JUNE Often considered the Often consideredthe

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49 ] hat can engineers do to make more than eight decades, control of the canal reverted to Pan- to very tall levees and referred to as a “wonder of the world” even more ama by treaty in 1999. Construction work on the $5.25-bil- the Borinquen Dams also were con- remarkable? lion expansion project, which was overwhelmingly approved structed on either side of the new When the question involves the Pan- by Panamanian voters in 2006, began in September 2007 channel to control the water levels ama Canal, an achievement often dubbed and was completed in June 2016. The new project is de- and prevent leakage. the eighth wonder of the world, the answer signed to augment the original system, which remains in Improvements were also made encompasses a series of international engi- operation. to the canal’s navigation channel neering efforts that recently expanded the ca- The centerpiece of the expansion was the construction of a by dredging millions of cubic me- nal, doubling its capacity and inspiring additional infrastruc- third set of locks with chambers that are larger than the 1914 ters of material from the ocean-lev- ture improvements around the globe. lock complexes in order to accommodate modern container el entrances, from , and WThe original portion of the canal, constructed by the Unit- ships and other types of vessels that are too large to traverse from the Culebra Cut (see “Wider ed States between 1904 and 1914, enables ships to pass be- the original canal. Located close to but separate from the and Deeper,” page 55). The spill- tween the Atlantic and Pacific oceans across the 80 km wide original lock complexes, the new locks again feature three ways and gates at , as . It has two sets of locks on both the At- stepped chambers on the Atlantic and Pacific sides, provid- well as other infrastructure at Ga- lantic and Pacific sides, along with a navigation channel ing a single, wider lane for transit. The project also includes tun Lake, also were modified to ac- through Gatun Lake and the Culebra Cut (also known as the an innovative series of water-saving basins. Each of the new commodate the raising of the max- Canal Route Gaillard Cut), a flooded valley that was excavated through lock chambers also features a pair of rolling gates at each end imum operational level of the lake the continental divide as part of the original canal construc- that open and close laterally, in contrast to the miter gates on by 45 cm to improve the canal’s tion. The locks are adjacent to each other, enabling ships trav- the original locks, which swing open and closed. water supply and draft (see “Rais- eling in opposite directions to pass. The three chambers of The project also involved the construction of a new, ing Gatun Lake,” page 56). each lock complex raise or lower the vessels 26 m in steps to 6.1 km long access channel for the new locks on the Pacific The expansion project was accommodate the difference in elevation between the ocean- side of the canal so that ships using the new locks can bypass constructed under a design/build level entrances and Gatun Lake, the artificial body of water Lake, an artificial lake that feeds into the original contract worth $3.2 billion that created inland on the Atlantic side as a reservoir for the canal. lock complex on the Pacific side. In this way ships can make was awarded by the Panama Ca- (Read “Between Two Oceans: The Panama Canal,” Civil En- their way directly to the Culebra Cut. Because the elevation of nal Authority, or acp (Autori- gineering, July/August 2014, pages 42–45.) the water in this access channel will be as much as 9 m higher dad del Canal de Panamá), the Although owned and operated by the United States for than the water level in Miraflores Lake, four structures similar agency in Panama that operates and maintains the canal, to an in- The new locks are larger than the original (1914) ones to ternational consortium known

accommodate massive modern vessels. BOTH CANAL AUTHORITY, OF THE PANAMA COURTESY as Grupo Unidos por el Canal,

[50] Civil Engineering JUNE 2017 JUNE 2017 Civil Engineering [51] Existing versus New Locks

Water Reuse Basins

sa. The consortium was led by Salini Im- Designed and constructed by an in Pasadena, California, and Iv-Groep b.v., gates for the new locks; and Hyundai, of South Korea, which 304.8 m long and provide an operating water depth of pregilo S.p.A., of Milano (Milan), Italy, and international team of engineers based in Papendrecht, the Netherlands. fabricated the filling and emptying system valves. The inter- 12.8 m. By comparison, the new locks are longer, wider, and included Sacyr Vallehermoso, S.A., of Madrid, and builders, the new locks are Among the numerous other consul- national consortium in charge of a crucial phase of the Pacific deeper, measuring 427 m in length, 55 m in width, and fea- Spain; Jan De Nul nv, of Aalst, Belgium; and the $3.2-billion centerpiece of the tants involved in the expansion project were access channel included fcc, of Madrid, Spain; ica, of Mex- turing an operating water depth of 18.3 m, according to infor- Constructora Urbana, S.A., of . $5.25-billion expansion project. Dredging International nv, part of deme, ico City; and the San José, Costa Rica, office of Constructora mation from the acp. The largest vessels capable of transiting The new locks were designed by Consul- of Zwijndrecht, Belgium, which was respon- meco sa. Various departments within the engineering di- the original locks are known as ships and have a ca- tores Internacionales del Canal de Panamá, llc, a joint ven- sible for the dredging to widen the Pacific entrance (Jan De vision of the acp also were responsible for key aspects of the pacity of 4,400 twenty-foot equivalent units (teus), the typi- ture led by the international engineering firmmwh Glob- Nul dredged the Atlantic entrance); Cimolai Technology expansion project. cal shipping containers that fill the cargo holds and are stacked al, now part of Stantec, with partners Tetra Tech, Inc., based SpA, of Carmignano di Brenta, Italy, which fabricated the ALL THREE CANAL AUTHORITY, OF THE PANAMA COURTESY The original are 33.5 m wide and on the decks of these vessels. The largest vessels capable of PHOTOCREDIT GOES HERE

[52] Civil Engineering JUNE 2017 0885-7024/14-0009-00??/$30.00 PER ARTICLE JUNE 2017 Civil Engineering [53] [ of 14,000 to asneo-Panamaxships,andtheseshipshaveacapacity passing throughthenewlocksarereferred bery, sels willstillbeunabletousethecanal,notesMikeNew- should anevenlarger, fourthsetoflocks ever provide sufficientrealestateforexpansion” of thenewlockcomplexes“wereselectedto ating thesystem,heexplains.Thelocations even moreexpensiveandrequiredwaterforoper every vesselafloatwouldhavemadetheexpansionproject adds. To makethenewlockslarge enoughtoaccommodate not tofollowthetraderoutesthatusecanal,Newbery some ofthelargest supertankers,butinanyeventtheytend Panamá. Theseships,dubbedpost-Panamaxvessels,include design managerforConsultoresInternacionalesdelCanalde G C 54 ont ates Even aftertheconstructionofnewlocks,someves- ] p r

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ture apairofrolling gatesateach The newlockchamberseachfea end thatopenandcloselaterally. - and thedeputydesignmanagerforConsultoresInternaciona- m Civil EngineeringbyNewberyandNickPansic, be needed,accordingtowritteninformationprovided the project,”Newberysays. powerful inprovidingtherightdesign,qualityto from 2007untilcompletion,a“continuitythatwasvery, very tec anditspartnersmanagedtokeepthesameteaminplace ther full-timeorpart-time,Newberyadds.Moreover, Stan- nents were working onelements of the expansion project ei- more than400engineerslocatedinofficesonthreeconti- Consultores InternacionalesdelCanaldePanamá’s efforts, sign ofthethirdsetlocks,notesNewbery. Atthepeakof . asce From aninitiallistof24potentialsitesfornewlockcom- , a Stantecvicepresidentinthefirm’s Chicagooffice - plexes, Stantecandthe making thefinalselections.Ultimately, the lantic sideand3for thePacific side) before duced thecandidatestojust6(3forAt- which eventuallyledtothede- les delCanaldePanamá’s Chica- performing other work, all of performing otherwork,allof to developamasterplan,and Brinckerhoff, nowpartof gineering firmsasParsons such other internationalen- ducting conceptualworkwith and supportingstudies,con- developing feasibility studies ma Canalsincethelate1990s, with variousworkatthePana- go designcenter. Stantec has been involved Stantec hasbeeninvolved acp graduallyre- p . e ., d wsp . ne , ,

PHOTOCREDIT GOES HERE COURTESY OF THE , ALL THREE

PHOTOCREDIT GOES HERE relation toaparticularpoint, the Dredging International, partof reachesern ofGatunLake was awarded to ing divisionandby an cal, andstructural branches ofthe nel designwas by performed thecivil, geotechni rock encountered inaparticulararea. The chan was reviewed withrespect tothetypeofsoil and as 304mwideatGatunLake, theslopedesign established. Butsincethereaches are asmuch erage sealevelatthe Atlantic entrance.) at thePacificentrance and0.06mbelow the av responds to0.3mbelow theaverage sealevel pld datum ( depth of9.14mwithrespect totheprecise level The siteswere dredged toaminimumdesign 3 were associatedwiththethird setoflocks. dredged, 17were partoftheoriginalcanaland dredging companies. tains thecanal;othersixwere owned by thority, or the dredges belongedtothePanamaCanal Au dredge, thelastusedforshoalchasing. Fiveof mechanical dipperdredge, andoneclamshell dredges, onetrailing suctionhopperdredge, one ter suctiondredges, fourmechanical backup ed two drillingandblastingbarges, fourcut navigation safetyalongthewaterway. range lighttowers were constructedtoimprove ter andonland. What ismore, 34steel-framed drilling andblastingoperations bothunderwa ing operations, andtheeffortwas supportedby moved viaearthwork, landdredging, anddredg the freshwater portionofthePanamaCanal. ered approximately50kmofthewaterway within lock complexes onthePacificside. The work cov struction ofthecanaltoconnectGatunLake tothe A By Luis Santanach Bernal Wider and Deeper a flooded valley created duringtheoriginalcon of theCulebra Cut(alsoknown astheGaillard Cut), asthecanal’sserves reservoir, andthedeepening deepening ofGatunLake, theartificiallake that the geotechnical branch andother civil andstructural branches withthesupportof range lighttowers were designedby the the agency inPanamathatoperates andmain The contract towidenand deepenthenorth A minimumchannel widthof218malsowas Of the20reaches withinthecanalthatwere The mainequipmentforthiswork includ A totalof24.9millionm³materialwas re . (PanamaCanalelevations are measured in

nal expansion involved the widening and nal expansion involvedthewideningand of therecent PanamaCa key component pld acp ) withadredging tolerance to8.53m (AutoridaddelCanaldePanamá), acp dredging team. The deme pld acp acp , , which cor based engineer offices. offices. acp ’s ’s ------less thanonemonth. The majorchallenges dur operations over alsowere aperiodof performed m³ ofmaterial.Underwater drillingandblasting backup dredge were usedtoexcavate 4million A cuttersuctiondredge, ahopperdredge, anda June 2010andwas completedinMarch 2012. in Zwijndrecht, Belgium. This work started in a cuttersuctiondredge. material, andtheremainder was dredged using ment was usedtoremove theupperpartof byand dredging performed JanDeNul m³ ofmaterialwas removed throughearthwork the canalcalledCartagena, atotalof3.8million confined strength of125MPa. an intrusiveigneousrock withanestimatedun places thedredges hadtocutthroughgabbro, during thePanamaCanalexpansion project: In centrally locatedinthenavigation channel. nearby Orquídea (Orchid) Island, which isless amounted to1.4millionm³. This was addedto was dammedtocreate theGatunLake reservoir, River,De LessepsIslandintheChagres which ers andotherpersonnelaboard thework boats. traffic controlofficetoensure thesafetyofdiv night carefully coordinated withthecanal’s marine 1914). The divingincludedhoistingoperations at construction ofthewaterway (between1904and equipment thathadbeenusedduringtheoriginal required toliftoutpiecesofrailroad tracks and of thecanal: Some171divingoperations were ing thiswork includedthefollowing: underwater Earthwork were equip performed. above, drillingandblastingfromtheland and and endedinNovember 2012. As mentioned Aalst, Belgium. The work beganin August 2010 To reaches widenanddeepenthe southern In thenewreach section of inthenorthern • Dredging thehardest rock encountered • Landreclamation: The materialtaken from • Removal ofoldequipmentfromthebottom removed atotalof24.9 key partsofthecanal. million m³ofmaterial Dredges andblasting to widenanddeepen nv , of of - - - - JUNE Continental, S.A. ( drid, Spain. The otherwas toIngeniería granted eight towers, was awarded to tion ofthe34range lighttowers. The first, for with canaltransits. sothatitwould notinterfereand performed canal. Sothiswork hadtobecarefully planned sectionofthe is thenarrowest andmostcurved lenge here involvedthefactthatCulebra Cut tober 2007andDecember2013. The majorchal rial by the the removal ofatotal3.2millionm³mate minster N.V., ofPapendrecht, the Netherlands. acp March 2007andendedinDecember2015. The 15 kmofchannel. These endeavors beganin in GatunLake, the signed themicropilefoundations, andthe ers thatwere locatedover thewater. and steelpilefoundationswere usedforthetow the towers thatcouldbeaccessedviaroadways, canal. Large shallow foundationswere usedfor ported thetowers locatedalongthebanksof dations were usedforthetowers: Micropilessup sion. Forthemostpart, three main typesoffoun owned by JanDeNulandby Royal Boskalis West the expansion project. cific water sector, was aprojectmanagerduring by thefloatingcrane ofthe supportedbyon aplatform pilesthatwere driven included theinstallationofthree towers located remainder ofthestructures. The lattercontract million m³ofmaterialwhilealsodredging division, which ultimatelyremoved atotalof13.4 manager forthePanamaCanal Authority’s Pa Luis Santanach Bernal, anengineerandwater engineering divisiondesignedtheother systems.

Two contracts were awarded fortheconstruc The deepeningoftheCulebra Cutrequired 2017 alsocontracted fortwo charter dredges acp Civil Engineering ’s dredging divisionbetweenOc iconsa acp relied onitsown dredging ), ofPanamaCity, forthe acp semi ’s dredging divi S.A., ofMa iconsa

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55 de ’s ’s ------] ------new lock complex on the Atlantic side was constructed about half a mile to the east of the original locks; the new Pacific complex is located about half a mile to the southwest of the Raising Gatun Lake original locks. Although the two new complexes operate identically, By Miguel Lorenzo there were considerable differences in the design and devel- aising the maximum operating level of Gatun Lake was one of opment of each site on the basis of such factors as geotechni- Rthe four main undertakings of the Panama Canal expansion proj- cal conditions, potential seismic loading, and ocean tidal el- ect. Its goal was to increase the storage capacity for water used for hu- evation ranges. For example, the Atlantic side features soft man consumption and other necessities as well as for the operations rock from the Gatun Formation that is easy to excavate but of the expanded Panama Canal. This effort makes it possible to raise decomposes when exposed to water. The excavation for the the maximum operating level of Gatun Lake by roughly 45 cm, from the new access channel on that side encountered what is called current elevation of 26.67 m with respect to the precise level datum Atlantic muck, an organic material with a consistency similar (pld) to 27.13 m pld. (Panama Canal elevations are measured in rela- to that of toothpaste. On the Pacific side, however, the rock tion to a particular point, the pld, which corresponds to 0.3 m below New, extended included basalt, which required blasting prior to excavation, the average sea level at the Pacific entrance and 0.06 m below the av- spillway gates were as well as a softer rock (La Boca Formation) and Pacific muck. erage sea level at the Atlantic entrance.) installed on the There were also several geological faults that crossed the Pa- The increase in the maximum operating capacity of Gatun Lake dam at Gatun Lake. equates to an additional storage capacity of about 200 million m³ of water, which would make possible about 1,100 additional transits each year. The undertaking had three main aspects: reservoir impoundment Several geological faults elements, operational efficiency, and damage prevention efforts. The reservoir impoundment elements were aimed at securely contain- ing the water of Gatun Lake up to the new desired level. The lake includes crossed the Pacific locks a dam that features a series of 14 sliding spillway gates that were extend- ed as part of the project to raise the lake’s operating level. The project also involved work on 32 miter gates in the Pedro Miguel Locks, located south maintenance. Two new sliding gates with extended heights were also ing division was a key player in these efforts, along with its operational complex and approach channels. of the Culebra Cut (also called the Gaillard Cut), and in the Gatun Locks, fabricated to serve as spare gates. hydrology unit and environmental management and monitoring section, located north of Gatun Lake, both sets of locks being part of the canal’s The damage prevention aspect included preservation work focused among others. cific locks complex and approach channels, which meant that original facilities. These original locks feature swinging miter gates, in con- on such canal facilities as piers, raw water intakes, and miscellaneous A series of tests involving prototypes of the major systems began seismic loads governed the design of the locks structure there. trast to the sliding gates of the new locks constructed during the expan- structures, as well as protecting and adapting other structures on private in October 2009 with a prototype of the proposed new hydraulic cylinders In fact, an active fault runs right beneath the Pacific side ap- sion project. The older locks also feature locomotives that assist the ships property that would be affected by the new maximum level of Gatun Lake. with semisubmersible technology for the locks’ miter gates. Additional proach channel and the Borinquen Dams lining the channel through the lock chambers; ships transit the new, third set of locks with (Eligibility for private property remediation was determined on the basis of prototype tests were carried out for the mechanical assembly designed and passes close to the lock complex itself. As a result, the the assistance of tugs. Complicating matters, the work had to be carried socioenvironmental criteria established by the Panama Canal Authority, or by the acp’s mechanical engineering section that would seal the gate yoke Borinquen Dams were designed to withstand a seismic ac- out while the canal remained in operation; there were no redundant or re- acp [Autoridad del Canal de Panamá] for the expansion program.) connections, as well as the miter seal extension of the gates. Tests were celeration of 0.98g, and the lock complex was designed to placement systems for these elements of the canal’s infrastructure. The damage remediation work involved 18 acp infrastructure and operat- also run on water-level sensors with commercial semisubmersible tech- withstand an acceleration of 0.72g. The miter gates of the original locks are opened and closed by hy- ing facilities. Provisions were made to mitigate any effects on the facilities’ nology that would replace existing technology, thus ensuring the required By contrast, the potential seismic loads on the Atlantic draulic cylinders. As part of the project to raise the lake’s operating operations or regular functions. The acp was required to work closely with functionality of the system under the new maximum operating level. side, while large, are only two-thirds as great as on the Pacific level, new hydraulic cylinders featuring semisubmersible technology the potentially affected operating units, carry out topographic and bathymet- All of the impoundment elements and the operational elements were side and did not govern the structural design. were installed, and flexible rubber grommets and screens were fabri- ric studies, conduct research, and construct and test prototype components. executed by acp personnel, except for the improvements to the ventilation Other differences between the new lock complexes in- cated and installed to isolate the cylinders. Moreover, the connection of The proposed solutions had to consider the long-term reliability of each system and the installation of bulkheads and watertight doors intended to volve the ocean tides at the canal entrances. On the Atlantic a yoke, which supports part of the miter gate system, was sealed, and component. isolate the lock machinery tunnels, which were assigned to local contrac- side, the design tidal range is approximately ±0.3 m, while the gates’ miter seals were extended. Furthermore, all of the openings Since much of this work involved the most critical infrastructure of the tors. This scheme made it possible to carry out work of greater technical on the Pacific side it is an order of magnitude greater, exceed- below 27.43 m pld in the machinery rooms at the upper level of the canal and was complex and highly specialized, the acp chose its own engi- complexity without affecting the reservoir capacity or ship traffic. ing ±3.0 m. This meant that the lock complexes on the Pa- Pedro Miguel and Gatun locks had to be sealed. neers and other experts to complete these projects. A balance was struck The remediation of more than a dozen operational infrastructure sys- cific side required deeper excavations, higher lock walls, larg- To ensure operational efficiency and safe transits through the Pedro between this new work and the regular functions of the acp’s employees, tems for the canal involved work on boat docks, fueling docks, and raw er approach structures and fender systems, and larger systems Miguel and Gatun locks at the new water level included the following: who maintain and operate the canal. The project also accommodated bud- water intakes, as well as on public boat ramps, a pilot dock, and tug and overall, including slightly larger water-saving basins to ac- • Isolation of the slots for the electrical conductors that power the getary limits; strict quality controls; and standards relating to the environ- launch landing locations. commodate the greater tidal ranges. locomotives; ment, safety, transparency, and accountability. The remediation work on private property in remote areas and areas Even the rainfall differs from one side of the isthmus to the • Relocation of the electrohydraulic systems of the miter gates and One of the first steps was developing detailed engineering designs difficult to reach on the shores of Gatun Lake was assigned to both acp other, averaging approximately 2.5 m per year on the Atlan- the isolation of the locks’ machinery tunnel by watertight doors in the hy- for all major components. These designs were developed through well- personnel and local contractors. These efforts included the relocation of tic side but just 1.7 m per year on the Pacific side. Construc- draulic cylinder rooms of the miter gates; documented review processes to ensure functionality, economy, and three houses, adjustments to other houses, and upgrades to docks, com- tion on the Pacific side also required the design and construc- • Installation of new, semisubmersible water-level sensors; constructability while minimizing effects on the regular operation of the munity structures, and parish facilities. tion of a 2 km long cofferdam to isolate the lower chamber • Improvement of the ventilation system of the machinery tunnel in system. The development of these designs involved support from various Once completed, these various efforts made it possible to increase the area from the Pacific Ocean. No actual cofferdam was need- both locks. disciplines and departments and covered aquatic and air logistics, state- maximum operational level of Gatun Lake to accommodate the new hy- ed for the Atlantic locks because they were constructed just These efforts also addressed the operations of the Gatun Dam of-the-art technology for earth and hydrographic surveying, community draulic demands of the expanded canal. downstream of Gatun Lake at a site that dated to an expan- spillway, a major component of the system for regulating the canal’s engagement and interagency coordination, the study and evaluation of sion project that was begun in 1939 but never completed. water resources, via the construction of two extended-height float- historical documentation, and extensive market surveys and interviews Miguel Lorenzo is an engineer and executive manager in the Panama Canal COURTESY OF THE PANAMA CANAL AUTHORITY OF THE PANAMA COURTESY That site already had a barrier separating it from Gatun Lake ing caissons. These caissons are used for performing spillway gate PHOTOCREDIT GOES HERE with world-class manufacturers and consultants. The acp’s engineer- Authority’s engineering division.

[56] Civil Engineering JUNE 2017 0885-7024/17-0006-0048/$30.00 PER ARTICLE JUNE 2017 Civil Engineering [57] as well as a natural “cofferdam” of unexcavated material sepa- age pipes and filters to collect any water that seeps through rating it from the Atlantic Ocean. the liner. The underground systems are also designed to pre- The 1939 undertaking played another role in the expan- vent water pressure from raising the liner when the basins are The various systems for filling and emptying the new chambers sion project. On the Atlantic side, the alignment of the new dewatered for maintenance, Newbery adds. set of locks matched the alignment of the locks proposed in To assist with the complicated seismic and hydraulic anal- 1939. As a result, the construction of the new lock cham- yses and other studies that the canal expansion required, require 7 percent less water than the original chambers. bers took advantage of the existing excavation, widening Stantec turned to the supercomputers in its Chicago office and deepening that space and constructing the water-saving and to simulia, which is headquartered in Johnston, Rhode of moving water from Lake Gatun through the culverts and the top. From there they slope down to a base roughly 20 m basins there adjacent to the earlier work, Newbery notes. Island, and is part of Dassault Systèmes. The models of the conduits into the lock chambers and back out again to the wide to accommodate the two water-conveying culverts lo- But on the Pacific side, to bypass Miraflores Lake, the 2016 lock heads, which house the chambers’ rolling gates, in- water-saving basins to make sure we could meet the very cated on each side of the chambers. Relying on gravity, the alignment differed from that of 1939. This meant that volved a total of 224 central processing units from several dif- stringent filling and emptying requirements,” explains New- main culvert draws water from Gatun Lake, whereas the aux- roughly two-thirds of the footprint of the water-saving ba- ferent sites and as much as 100 hours of computer running bery. The modeled hydraulic performance of the new locks iliary culvert, which is linked to the main culvert, distributes sins on the Pacific side had to be constructed atop the 1939 time, “which we believe is unprecedented in our industry,” and basins was later confirmed with measurements dur- water into the lock chambers and also draws water from the excavations. Thus, the elevation of the site for the Pacific Newbery notes. ing the commissioning of the locks (see “Testing the New adjacent water-saving basins. The main culvert is more than basins was now too low, Newbery says. The solution in- Stantec’s office in Buenos Aires, Argentina, also conduct- Locks,” below). 8 m wide and approximately 6.5 m tall. Unlike the 1914 volved cleaning out the site, backfilling it with rock up to a ed numerous numerical hydraulic model studies, and a 1:30 Stantec also worked closely with Autodesk, Inc., of San lock chambers, which are filled and emptied through open- certain level, and then adding a finer material above that to scale physical model of the new lock chambers was construct- Rafael, California, to produce facilities information manage- ings in the floor of the chamber, the new lock chambers fea- bring the land to the appropriate elevation for the new ba- ed at a laboratory belonging to cnr, which is headquartered ment (fim) models for clash detection studies involving the ture a side-filling system with a series of 20 ports in each of sins, Newbery explains. in Lyon, France. Measuring 60 m long and 10 m wide, the mechanical and electrical systems, as well as other aspects of the lock chamber walls. Altogether, the various systems for The nine basins at the new lock complexes are each ap- physical model featured scale models of vessels that were test- the expansion project. Overall, “this was the largest applica- filling and emptying the new chambers require 7 percent proximately 70 m wide, 5.5 m deep, and 407 m long. As not- ed in the model lock chambers. The latter were operated with tion of fim modeling on a major civil works project,” New- less water than the original chambers, even though the new ed previously, they are slightly larger on the Pacific side but three model water-saving basins to test the filling and emp- bery says, and the design team used those modeling tools “on chambers are considerably larger. generally match the length of the chambers they help to fill tying of the chambers as well as the key forces that would be a larger scale than had ever been done before.” The 16 rolling gates that close off the 55 m wide lock and empty. The basins feature a thick polyvinyl chloride liner exerted on the hulls of the ships. The new lock chambers are constructed of concrete and are chambers are massive steel-framed structures. There are for waterproofing, along with a system of underground drain- “We used all these models to analyze the various aspects as much as 30 m deep, the walls approximately 2 m thick at three types in each lock complex, and they are arranged in

in the locks can increase the force required to two on the Pacific side, to measure the surface information required to understand how the sys- restrain a vessel during lockage. Other limiting water velocity in the approach channels on the tem performs in relation to the requirements. Testing the New Locks hydraulic parameters are no cavitation, no air centerline of the locks. Active construction pre- Field-testing every operating condition that was entrapment, and no water hammer (which refers cluded deployment of a second profiler on the tested in the physical model was not feasible. By Norman F. Perkins, p.e., to abrupt and potentially damaging increases Atlantic side. Whenever possible, the performance team m.asce, Daniel Gessler, in water pressure when a valve is opened or • A series of permanent water-level sensors completed the testing at the actual lock under closed), and maximum water velocities were also were installed to monitor the water levels in operating conditions in which the laboratory Ph.D., p.e., d.wre, m.asce, established in the lock approach channel. Water the lock chambers and the water-saving basins. testing had shown the system performance to and Philip S. Stacy conservation is also critical to minimize the en- The data acquisition system monitors water lev- be closest to the limits set by the acp. For cases vironmental effects of the canal operations. els at 27 separate locations on the Atlantic side in which it was not possible to test the actual he recently completed third set of locks at To verify compliance with these require- and 27 on the Pacific. lock for the most adverse performance condi- Tthe Panama Canal incorporates several civil Water-level sensors ments, the performance team and the interna- • Valve position sensors were installed on tions, the available testing was used to deter- components and hydraulic design features that monitored 27 locations tional consortium known as Grupo Unidos por el each of the valves that control the flow of wa- mine how the lock’s performance differed from on the Atlantic side of are intended to reduce routine maintenance and Canal, sa, which held the design/build contract ter into and out of the lock chambers. The sys- the physical model. conserve water. For instance, rather than relying the canal and another to construct the new locks, installed and moni- tem monitored 52 valve positions through- The field-testing was critical in demonstrat- on the locomotives used in the original locks, the 27 on the Pacific side. tored a series of sensors and other measuring out the testing period. Furthermore, 16 culvert ing to the project owner how system perfor- ships transit the new locks with assistance from devices throughout the lock complexes: valve positions and 36 conduit valves also were mance compares with the design specifications. tugboats. Water-saving basins are used to reduce • Twelve temporary water-level sensors that monitored. The independent testing was also used to deter- the freshwater requirements from Gatun Lake. were accurate to within 0.5 mm were installed in All of this equipment was able to interface mine if the design/build team had satisfied its While these efforts confer important benefits, the lock chambers (six in the Atlantic locks and with a custom-designed central data acquisition contractual obligations for design and construc- they also present various hydraulic challenges six in the Pacific locks). The sensors measured system to log data for testing in order to confirm tion of the system. Independent performance that can affect not only the number of ships pass- sachusetts; Cameron, part of Schlumberger; Flow- maximum allowable filling times, maximum the water surface slope during the filling of the that the design requirements were met. testing is an important aspect of large design/ ing through the canal, which is limited by the meter Service, of Northampton, Massachusetts; allowable water surface slopes in the locks, chambers, as well as the water level in the cham- The limited but systematic testing performed build projects in that it gives the project owner speeds at which the lock chambers are emptied and Rennasonic, Inc., which has offices in East Fal- maximum allowable velocities in the culverts bers, so that the flowmeters could be calibrated. on the lock complexes enabled the performance and the bidders assurance that the design/build and filled, but also the water surface stability dur- mouth, Massachusetts, and Naples, Florida. and conduits, and required water conservation. • Forty-eight pressure sensors were in- team to determine compliance with the require- team will satisfy the project specifications. ing the emptying and filling of the chambers. Prior to the design and construction of the These requirements were critical to the success stalled, half in the Atlantic locks and half in the ments for the test conditions. Moreover, the As part of the commissioning phase of the new new locks, the Panama Canal Authority, or acp of the new locks because slower filling times Pacific locks. team also considered the results of tests from a Norman F. Perkins, p.e., m.asce, is the chief op- locks, the key hydraulic parameters associated (Autoridad del Canal de Panamá), developed a than expected would reduce the number of lock- • Eight flowmeters were installed, again half 1:30 scale physical model of the new locks con- erating officer, Daniel Gessler, Ph.D., p.e., d.wre, with these challenges were tested over a 10-week set of requirements that defined the perfor- ages per day, while velocities higher than allow- for the Atlantic side and half for the Pacific. ducted in Lyon, France. Analyzing the physical m.asce, a vice president, and Philip S. Stacy the period by a so-called performance team consisting mance characteristics that the locks would able could lead to a deterioration of the concrete PHOTOCREDIT GOES HERE • Three acoustic Doppler current profil- model testing data together with the field data director of calibration services at Alden Research

of Alden Research Laboratory, Inc., of Holden, Mas- have to meet. These specifications included lock structure. Excessive water surface slope INC. ALDEN RESEARCH LABORATORY, ers were installed, one on the Atlantic side and from strategic testing provided the acp with the Laboratory, Inc., of Holden, Massachusetts.

[58] Civil Engineering JUNE 2017 JUNE 2017 Civil Engineering [59] The walls of the new locks also feature an external drainage system designed to reduce the hydrostatic pressure on the outsides of those structures.

pairs. Each gate is 57.6 m wide. The gates range in size from Dams involved the use of both a primary and a secondary 22.28 m tall and 8 m thick for the ones farthest inland on each grouting to seal the rock beneath the structure. The dams side of the canal to 33.04 m tall and 10 m thick for the gates themselves, which are as much as 100 ft high, are zoned em- closest to the Pacific entrance to accommodate the aforemen- bankments that feature a clay core protected by filters and tioned tidal variations there. Although the gates each weigh have sloping rock walls armored with riprap. between 2,313 and 4,242 metric tons, they feature buoyancy At the approaches to the lock complexes at either end chambers that enable them to float and thereby roll on rails at of the canal, reinforced-concrete guide walls help align just 15 percent of their actual weight. the neo-Panamax vessels as they enter the chambers. An One problem with the miter gates on the original locks is array of fenders designed to cushion ship impacts helps that they require considerable maintenance, notes Stantec’s ships safely maneuver into the chambers with the aid of Pansic. “And whether that involves damage from a vessel im- tugboats. pact or just that they need to be recoated for corrosion protec- Both the Atlantic and the Pacific lock complexes house tion, it’s a fairly elaborate and time-consuming process to re- the supplementary systems needed for operation and main- move them and take them to a dry dock where you can work tenance, including enclosed galleries that provide dry access on them,” he explains. Moreover, that canal lane must be shut beneath the chambers. High-mast lighting systems facili- down, sometimes for a considerable amount of time, until a tate around-the-clock transits, and duplicate loop power sys- replacement gate is installed. tems connect all critical oper- But since the expansion ating equipment to two power project added just one lane, supplies as well as to a stand- the locks must remain in op- by generator. Each lock com- Because the new locks are part of a single lane, they must remain in eration even if a gate requires plex has 60 support buildings, operation even when a gate requires maintenance or repair. maintenance or repair, Pansic including machinery build- says. The solution involved ings that house the electrical the use of rolling gates in and mechanical equipment inauguration of the expanded facilities, which took place canal can offer,” Pansic explains. These pairs, each gate having a re- for lock gate and valve opera- on June 26. “More than 100 years ago, the Panama Canal investments, he adds, “wouldn’t have cessed space into which it can tions, as well as other opera- connected two oceans,” noted Jorge L. Quijano, the acp’s happened if the canal hadn’t been be retracted and then sealed tions and maintenance struc- chief executive officer. “Today, we connect the present and expanded.” CE off with a bulkhead. The re- tures. Other site infrastructure the future.” cessed area can then be dewa- includes access roads, storm Since then, the expanded canal has experienced several con- Robert L. Reid is the senior editor and features tered and the gate repaired or drainage, security fencing, and secutive months of record daily tonnages for ships availing manager of Civil Engineering. maintained in the dry while surveillance and access-control themselves of the new locks, and in March 2017 the 1,000th Reid its duplicate continues to open systems. neo-Panamax ship passed through the waterway. The expan- PROJECT CREDITS Owner: Autoridad and close the chamber for ship To mitigate the expansion sion also opened the canal to new market segments. In July del Canal de Panamá (Panama Canal Authority) Design/ transits, Pansic explains. project’s effect on the Pana- 2016, for example, the first tanker transporting liquefied nat- build consortium: Grupo Unidos por el Canal, sa, consisting “With the single lane of locks there was a The new rolling gates range in manian environment, ecological compensa- ural gas ever to enter the canal transited the new locks, and the of Sacyr Vallehermoso, S.A., Madrid, Spain; Salini Impre- huge premium on high reliability and high height from 22.28 m to 33.04 m, tion and reforestation efforts were conducted number of such tankers using the locks has been exceeding gilo S.p.A., Milan, Italy; Jan De Nul nv, Aalst, Belgium; availability of all of the systems,” Pansic notes. depending on location. throughout the country, resulting in the res- the acp’s expectations, averaging more than five per week, not and Constructora Urbana, S.A., Panama City Third set of “So the rolling gates proved to be the most cue and relocation of more than 6,000 mam- the one per week that the acp expected. locks joint venture design team: Consultores Internaciona- reliable and the most available lock gate system for that mals, birds, reptiles, and amphibians, as well as the estab- And it’s not just Panama that has benefited from the expand- les del Canal de Panamá, llc, consisting of numerous of- application.” lishment of nearly 1,000 hectares of new vegetated spaces ed canal. According to an acp press release that announced that fices ofmwh Global, a Stantec Company; Tetra Tech, Inc.,

The walls of the new locks also feature an external drain- at parks, forests, and other locations. In essence, each hect- BOTH 1,000th neo-Panamax vessel, “ports around the world, and in Pasadena, California; and Iv-Groep b.v., Papendrecht, the age system designed to reduce the hydrostatic pressure on the are affected by the expansion program was offset by two new particular along the U.S. East Coast, have already expanded or Netherlands Pacific entrance dredging: Dredging Interna- outsides of those structures, an idea that Stantec initially de- “green” hectares. are in the process of deepening and widening their channels to tional nv, part of deme, Zwijndrecht, Belgium Atlantic veloped for a U.S. Army Corps of Engineers project involving Archaeological and paleontological items discovered accommodate the influx of neo-Panamax vessel traffic due to the entrance dredging: Jan De Nul nv, Aalst, Belgium Gate fab- locks in Kentucky. The acp agreed to use a similar system during the excavations and other work for the expansion expansion.” Moreover, many of these ports have also experienced ricator: Cimolai Technology SpA, Carmignano di Brenta, on the new set of locks provided that it could be easily main- project were recovered and preserved with the assistance record tonnage months, the acp release noted. Italy Pacific access channel consortium: fcc, Madrid, Spain; tained, Newbery notes. So the drains were included behind of the Smithsonian Tropical Research Institute, which is Pansic says he’s seen improvements and upgrades to mar- ica, Mexico City; and Constructora Meco sa, San José, the walls, along with shafts to provide maintenance access, he based in Panama. More than 5,300 rock and sediment itime infrastructure projects around the world, from U.S. Costa Rica, officeLock complexes testing: Alden Research says. The drains themselves are “about six feet high and two samples and more than 3,400 fossils were collected and inland waterways to Europe, Asia, and the Persian Gulf. Laboratory, Inc., Holden, Massachusetts; Cameron, part of feet wide, so you can literally walk inside and clean them out cataloged. There’s been “a huge knock-on effect in terms of driving Schlumberger, Houston office; Flowmeter Service, if you need to,” he explains. Functionally completed in early June last year, the new investment in other facilities, larger maritime port facil- Northampton, Massachusetts; and Rennasonic, Inc., East

On the Pacific side, the construction of the Borinquen locks underwent a series of successful trials prior to the CANAL AUTHORITY, OF THE PANAMA COURTESY ities...to better take advantage of what the expanded Falmouth, Massachusetts, and Naples, Florida

[60] Civil Engineering JUNE 2017 JUNE 2017 Civil Engineering [61]