三峡工程双线五级船闸设计.docx

The design of double-line fivestep ship-lock of Three Gorges Projec Niu Xin qiang，Tong Di，Song Wei bang(Changjiang Institute of Survey，Planning，Design and Research，Changjiang Water Resources Commission，Wuhan 430010，China)Abstract：The general design and layout of the doubleline fivestep shiplockthe water delivery technique for high head shiplock，the key technical problems of fully lined shiplock and the monitoring techniques for largescale miter gates and hoisting equipment under complicated operation conditions of Three Gorges Project(TGP)are introducedSince the operation of shiplock in 2003，the operation practice has proved that the design techniques are advanced，ra tional and reliableThe design and construction of the fully lined shiplock promotes the development of design theory and practice of shiplock projects，which makes the construction technology of shiplock in the world reach a new leve1Key words：Three Gorges Project；doubleline five-step；design of shiplock1 Introduction The Yangtze River is the largest fiver in ChinaAccording to navigation plan，Yangtze River is a ClassInavigation channel，and opens to the navigation in anordinary yearwith its annual traffic volume about 80of total inland river traffic volume in China BeforeThree Gorges Project(TGP)is built，about 660 kmlong river channel from Yichang to Chongqing in upper Yangtze River is fu11 of rapids and shoals with acomplicated water flow conditionIn this channel，onlya 3 O00 t fleet consisting of 800 1 000 t barges can cross at the most，and annual oneway throughput eapacityfor this channel is only about 10 million tAfter TGPis completed，navigation condition in upper channel ofreservoir re on has been ultimately improved，and a 10000 DWT fleet can cross from the lower reach nonstopthrough Jiulongpo Port in approximately half the time ofevery yearThrough the flow regulation of this hydrauliccomplex， navigation condition in navigation channeldownstream of the dam during lowwater season has beenmarkedly improved，and annual odeway throughput capacity of upper and middle Yangtze River can be increased up to 50 million t The key structure of Three Go rges shiplock isClass-1 with a design total head of 113 ma maximumnavigation discharge of 56 700 m s，and has an annualoneway planned cargo tonnage through the dam site at2030 design level year of 50 million tThis shiplock isarranged at a doubleline fivestep mannerTh e maximum operating head for water conveyance of its lockchamber is 452 mand its effective sizes designed inthe light of a throughputcapacity of 10 000 tonnage fleetare 280 m x34 m x 5 m f length width minimum water depth above sill 1 rhe ship1ock is built in a rock tank deeplyexcavated at left bank of the dam site，with a maximum height for this excavated slope of 170 mand lock head and lock chamber ale al1 of separation linedtype structure This double1ine fivestep ship-lock is a large-sized fully-lined ship-lock that call meet navigation conditions of upstream and downstream shiplock at present in the world，solve the quick and safe water conveyan ce of lock chamber as well as address the huge technical dificulty of shiplock structure2 General design of ship-lock The overall design of Three Gorges shiplock is carried out mainly according to the overall benefit of Three Gorges Project and shiplock that are affected， he technical feasibility and advancement of shiplock as well as quantities of work and construction cost etc，and some significant technical problems affecting the whole situation are studied and decidedIn view of such features as complicated water flow and sediment conditions at dam siteship1ocks overall design head of 1 13 m as well as major structures built in deeply excavated rock tank。design studies for overall design of ship1ock were conductedwhich had solved the following significant problems21 Layout of ship-lock built in sedim ent-laden river Since the dam site of Three Gorges Project is located in a stronglycurved reach with a nearly right angle，the upstream and downstream shiplocks lines are intersected with main flow in Yangtze River at a large angle，and a transverse velocity higher than navi gation standard is formed at the entrance zone of the approach channe1It can not meet the requirement that a ship safely sails in and out of the entrance zone in this approach channel；as during flood season there is a large amount of sediment accumulated in water flow of Yangtze River，after the TGP operates for a given term of yearsand sediment accumulated will change the navigation dimension and water flow conditions of this navigation channel， which causes the navigation water flow condition required at the entrance zone of approach channel not to be ensured Through extensive and multialternatives eompara-tive studythe location of ship1ock line was determined to adopt a line 1ocated at the left side of Tanziling and the maximum elevation of left bank at dam site Measures such as building separation dikes at right side of upstream and downstream approach channels，optimi zing the location of approach channels entrance zone， djusting the intersection angle between axial line at preach channels entrance and water flow at main chan-Hel have been taken to make the water flow condition at the entrance zone of the approach channel meet the nayigation requirement for a long period of time For navigationobstructing problem due to sediment accumulation during flood season overflow dam is utilized to discharge flood and high flow is used to remove sedi ment，so as to reduce the sediment accumulated in approach channe1 Under the condition without the dam construction upstream of the hydraulic complex，a large am ount of model tests show that after the project operates for dozens of years or even more than one hundred years， only sediment accumulation in l0ck approach can obstruct the navigation，an d the positions of sediment accumulation are located beyond approach chan nels entranceMeasures of the flushing sediment through flowing water which had been successfully applied in lock approach of Gezhouba Hydraulic Complexdownstream of TGP，is anlikely to obtain a markedly effect at Three Gorges ship lock；as for navigationobstructing problem due to sediment accumulation that probably OCCUrs when TGP operates for a longterm，it is determined through study and analysis that the priority to mechan ical de-silting is Ven and supplemented by rebuilding a tempo rary ship-lock in-to a flushing sluice and lowering the down stream wate needed to be formed by deep excavation in a mountain-OUS body，and diferent structural forms adopted for the shiplock will have a striking influence on construction costIf a separation gravity type or integrated type is conventionally adopted for the shiplock structure，it is comparatively simple in technology with extensive construction experience，but the rock excavation and concrete placement are great in quantities of work and hi ghin construction cost The bedrocks at Three Gorges shiplock are amphiboleplagioclasegranitite，and COBparatively intact with a high wet compressive streng thand a strong ability to bear the loadBut since it is necessary to ensure that the location between rock mass and lock wall can jointly stress and control the deformation of rock slope，it is greatly difficult in resolving key technologyThrough studies，integrated technical measures such as strengthening and supporting rock masses，closing slopes surface， dewatering and draining groundwater and controlling excavation lasting，as well as studying the mechanism that lined lock wall and rock masses are jointly stressed，and ensuring that lock wall and rock masses behind the wall can reliably jointly crate and control deform ation etc，have been takenIt is determ ined that the fullylined structure is adopted for Th ree Gorges ship-lockAfter the doubleline shiplock is adopted as a fullylined structure and arranged at a paralleling and continuous five-step manner，the contradiction between the shiplocks line and the general layout of hydraulic complexs other structures is smaller，and the shiplock can be operated and managed in a centralized and convenient manner，which evidently reduces qu an tities of work and saves investment for this project，promotes the technical level of shiplocks structure an d provides a technical basis for adopting fullylined structure in building ship-lock project at the bed-rock dam site upstream of water courselevel at the end of the flood season and flushing the sediment by lowdischarge，and the room at fight side of Three Go rges shiplock is preformed to build a flushing tunilel so as to increase the conditional po ssibility of flushing discharge，an d ensure that the lock approach can still meet the requirement of navigation dimension after reservoir sediment accumulation in Three Go rges shiplock reaches an equilibrium22 W ater conveyance of ship-lock at a super high head The water conveyance for Three Go rges ship-lock at an overall design head of l 13 m is related to the layout of this shiplock in the hydraulic complex，the difficulty to s0lve hydraulics problem for shiplock and the equirements needed for operation and management， the throughputcapacity，the qu antities of work and the con struction cost as well as the feasibility and technical advan cement of ship1ock structure at is considered for first of all is that the overall design head of shiplock must be classified reasonablyAs for e Go rges shiplocka variety of schemes such as the separated layout of threestep shiplock，continuous layout of fourstep and fivestep shiplock as well as the continual layout of threestep thriftlock etchave be en studied successivelyTh e total head of the shiplock is classified mainly considering the topography and geological conditions of dam site as well as the combination of upstream and downstream water levels for this shiplock etcand taking thecurrent level of ship-locks water conveyance technology into accountIt is apparently higher than any of existing ship-locks with a high head in the wodd in the light of classified head But through efort from design ers ，according to the principle of ensuring a certain degree of confidence in technology，a scheme was adopted，nam ely the overall design head is equally divided into five steps， and double-line ship-locks are arran ged in a paralleling an d continuous fivestep iDoA3nerAt a max imum operating head of 452 m for intermediate step ship-lock，the ship-lock has a maximum filling and emptying water body of 237 000 m at one time and the filling and emptying time can be controlled wi thin 12 minThrough indigenous innovation，water conveyance system and wall structures are arran ged in a separated n3anner，and a basic technical measure of raising the flooding water depth at the top of valve gate is adopted in combination of introducing advanced water conveyance technology from other high head shiplocks，which has solved the water conveyance problem of Th ree Go rges shiplock wi th a super high water head23 Structural form of ship-lock on rock foundation According to selected shiplock line，a lock tank is tota1Center line ofupstream approach channel is a 930 mlong straight segment from upstream face of No1 lock headconnecting a curve bend with a radius of 1 000 m and a centre angle of 42。and again joining 450 m long straight segment， extending to the head of upstream separation dikerI1he approach channel has a total length of 2 113 m with a bottom width of l80 m for normal segment and a chan nel bed elevation of l30 mAbove the entran ce of upstream approach channel is the 530 m long entrance zone with a bottom width of 220 m：after a curve bend th a radius of 1 20o m and a centre angle of 28。 is upstream connectedit connects with sailing route in reservoir region in a tan gent line manner e right side of upstream approach channel is providedvitl a 2 680 m long separation dike Center line of downstream approach channel is a 930 m long straight segm ent downward from downstream face of No6 lock head，connecting a curve bend with a radius of 1 000 m and a centre angle of 54。and again joining 850 m long straight segm ent，extending to the head of down stream separation dike 111e approach channel has a total length of 2 708 m with a bottom width of 180 m for norm al segment and a channel bed elevation of 5650 mBelow the entrance of downstream approach channel is a 530 m long entrance zone with an entrance width of 200 mand it connects main channel after its upstream ioins a curve bend with a radius of 1 000 m and a central angle of 10 oThe right side of upstream approach channel is provided with a 2 680 m long separation dike The general layout of Th ree Gorges shiplock is shown in Fig1 32 Layout of structures and equipment Ship-lock at every line for Three Go rges doubleline shiplock includes upstream and downstream appreach channels and their navigational guiding an d berthing structures，6 lock heads and 5 lock chambers located in major structure segment 321 Layout of major structures Major structures for Three Gorges doubleline shiplock are arranged in a deeplyexcavated lock tank and all of them are of separation linedtype structure Between double1ine ship1ocks remains a rocky separati0n wall with a bottom width of 57 mElevation at lock top is 18500 m for No1 lock head，17900， 160O0 m and 13900 m respectively for No2。No3 and No4and 1l667 m for N05 lock head Structural segments for No1 N05 are 265。 26352655，2655 m and 2542 m respectively Elevations at wall top are 179O0，16000，13900， 1 166 m and 9662 m respectively Main water conveyance adits are arranged at northem and southern slopes and within rock masses of intermediate wal1The upstream forward intake box culvert is arranged at the bottom of approach channel in a manner symmetrical to shiplocks centerline；two emptying box culverts across separation dike are provided for emptying water for water conveyance system ，through which water in lock chamber is directly released into Yangtze River and an auxiliary emptying culvert is arranged within the lock wall of No6 lock headEvery main water convey ance adit is equipped with 6 sets of valve wells，all of which aye excavated within rock mass and formed by re inforced concrete lining322 Metal structures and hoisting equipment Three Gorges shiplock is arranged from upstream to downstream in sequence with the following equ ipments： emergency bulkhead gate and bridge hoist at N01 lock head，miter gates an d hydraulic hoists at No1N06，an d floating bulkhead gate at downstream of No6 lock head；the mi ter gate is 375385 m high，and the width of a single gate is 202 m；the maximum subm ersion water depth for miter gate at No1 lock head is 35 mSome equipments aye arranged in the water con veyan ce system in sequ ence as follows： intake trash racks，water conveyan ce ogee gates at all levels and hy draulic hoists，upstream an d downstream bulkhcad gates for water conveyance ogee gate，service valve for auxiliary emptying culvert at No6 lock head an d hoists as well as upstream bulkhead gate Water conveyan ce ogee gate has a size of45 m55 m (width height)for No1 and No6 lock heads，42 m x45 m (width height) f0r 2 5 lock heads1he miter gate is hoi sted by a horizontal cylinder hydraulic hoist；the water conveyance ogee gate is lifted by a vertical cylinder hydraulic hoist，and two sets of equipment share a hydraulic system323 Electrical equipment Ship1ock at every line is installed with a set of monitoring system including an insitu operating floor and a centralized monitoring floorThe centralized nonitoring floor comprising of centralized control devices，and navigation command signal devices，industrial TV sets and monitoring devices， and broadcasting and communication equipment can fulfill the tasks such as centralized automatic control and monitoring command for singleline continuous ship-passing operation The if1situ operating floor includes insitu control stations (substations)distributed within 12 hoist rooms at 6 lock heads and water level detection devices，as well as opening detection equipments for miter gate and water conveyance ogee gate The insitu control station adopts a redundant con trol structure and uses programmable logic controllers f PLCs) as its main control units and 2 PLCs are equipped in two substations of the same lock head and operate each other in a hotbackup mannerThe inter communication between substations adopts PLC net work communication manner In additionit also adopts lowlevel hard connection between IO points through cablesTh e effect of the insitu control station iS to accept and implement centralized control orders to control the reliable operation of insitu equipments，and at the same time，when the centralized control equipment can not work well due to failure in centra1ized control equipment or centralized control network it can operate the in-situ unit on its own with a latch up protection function4 Structural design of shiplock41 Structural layout A longitudinal ioint is provided between bottom panel and lock walls at two sides of Three Gorges ship一 】oekThe lock wall iS of fully1ined or hybrid type The lock head along the flow direction consists of gate recess segment and supporter segment ibr miter gate Most of supporters for miter gate adopt gravity linedtype structure， and some adopt a hybrid typestructure，namely gravity linedtype at lower part and gravity type at upper part Structural anchor rods are arranged Of th