黃金水道解“鎖”密碼

本刊記者 徐 華

黃金水道解“鎖”密碼

本刊記者 徐 華

2011年3月，交通運輸部發(fā)布了《關(guān)于貫徹國務(wù)院關(guān)于加快長江等內(nèi)河水運發(fā)展的意見的實施意見》，標志著我國加快內(nèi)河水運發(fā)展進入實施階段。然而，一個不容忽視的現(xiàn)實是，在航道整治駛上快車道的同時，諸如橋梁、閘壩等礙航狀況更顯突出。二律背反規(guī)律表明，任何局部或環(huán)節(jié)最優(yōu)往往會損害系統(tǒng)整體的利益，長江各方涉水因素，都在有形或無形地影響著長江通航能力的綜合發(fā)揮。

跨江大橋再拔高

長江通江達海、水量充沛，有優(yōu)良的航運條件。1931年，美國萬噸級“加利福尼亞”油輪曾自長江口直達武漢。然而，現(xiàn)在萬噸級船舶要實現(xiàn)江海直達更多地要看橋梁的臉色了。凌空飛架的橋梁使萬噸級海輪的長江之旅只能淺嘗輒止。

目前，我國長江干線跨河橋梁有60座之多，其中江通長江大橋、江陰長江大橋等5座大橋凈空在32米以上，可通過萬噸級海船外，其它均在24米以下。其中，中下游通航凈高度普遍為24米，共有11座，一般可通過5000噸級單船或萬噸級船隊。中上游橋梁的通航凈高度普遍為18米，共有41座，一般可通過3000噸級船隊。造成我國跨江大橋凈空普遍過低的主要原因是最早建成的南京、武漢長江大橋凈空為24米，其后的橋梁都錯誤地參照了這個標準，例如黃石、九江、銅陵等橋梁。其凈空尺寸遠小于壓載時萬噸船舶吃水線到桅頂高度。正是跨江橋梁凈空參考標準過低，導(dǎo)致橋梁在溝通南北交通時，卻卡住了長江東西水運。

從這一點來看，美國密西西比河流域開發(fā)則更加注重保證航運的通航要求。自圣路易斯以下到河口1600公里的河段僅建兩座大橋，平均800公里一座。眾多的跨江橋梁，大都在河流上游和支流。密西西比河上下7座大橋有6座均在47米以上，海輪可上行到距河口4056公里處。

由于建成橋梁限制，南京至銅陵213公里可供萬噸級海輪通航的深水航道未得到充分利用。國家自上世紀80年代以來，先后投資數(shù)十億元在蕪湖、安慶、九江、黃石、武漢、城陵磯、重慶等港口建成的數(shù)十座5000噸級外貿(mào)碼頭和集裝箱碼頭，卻很少有大型外輪靠泊。橋梁凈空過低成為長江中上游廣大地區(qū)出海物流大通道的瓶頸。

據(jù)交通運輸部總工程師徐光介紹，研究表明，萬噸級海船直達安慶是較為經(jīng)濟合理的運輸范圍，首先，航道自然條件和建設(shè)可能性大。目前，安慶以下航道通過治理具備在枯水期達到6米水深的條件，中洪水期基本滿足萬噸級海船通航要求。安慶以上枯水期只能達到4.5米水深，繼續(xù)提高航道水深技術(shù)上存在很大難度。其次，水路運輸組織的經(jīng)濟規(guī)律性最優(yōu)。與中轉(zhuǎn)運輸相比，海船直達雖然減少中轉(zhuǎn)換裝環(huán)節(jié)，但海船造價和航行成本相對較高，到一定范圍后，直達不具有成本優(yōu)勢。經(jīng)測算，在回程貨裝載率達到30%以上時，萬噸級海船直達安慶相對中轉(zhuǎn)運輸具有經(jīng)濟合理性。綜合考慮，安慶以下是萬噸級江海直達相對合理的范圍。

那么，從長江航運的長遠看，安慶以下橋梁就有必要考慮提高跨江大橋的跨度和凈空標準。例如通過技術(shù)改造，提高現(xiàn)有橋梁尤其可適宜萬噸海輪河段橋梁的凈空高度。據(jù)專家介紹，目前提高橋梁高度有幾種方法：一是加高橋墩，抬高橋梁；二是改造大橋，使其中一個橋孔提升為活動橋。萊茵河上就有一些橋梁采取這種方法；三是建造適應(yīng)現(xiàn)行橋梁跨度的大型標準船舶。例如，2007年9月21日，從寧波港出發(fā)首航到武漢鋼鐵工業(yè)港的“江夏文”號萬噸級貨輪，桅桿可以收起。另外，還可以將船舶駕駛臺建造成為可升降形式，以便控制過橋時船舶的高度。

三峽樞紐能力效率齊升級

三峽工程具有防洪、發(fā)電、航運等綜合效益。然而，自從1997年大江截流以來，長江干線航運卻走過了一斷不尋常的坎坷之路。從明渠到臨時船閘，三峽的通航能力始終明顯不足。為了解決這一問題，1998年，翻壩過閘開始出現(xiàn)。這作為當時三峽建設(shè)中的臨時之舉實為無奈。然而，2003年6月15日，三峽雙線五級船閘投入運行，長江航運正常通航之后，翻壩卻依然擔(dān)負著大量的過閘物資轉(zhuǎn)運的重要作用。

據(jù)報導(dǎo)，三峽船閘自2003年6月16日投入試運行以來，雖然通過科研和實踐摸索不斷改進船閘調(diào)度與管理，船閘通過量有所提高，但是由于船閘實際通過能力2460萬噸與設(shè)計能力5000萬噸存在較大差距，難以實現(xiàn)快速過壩，船舶滯留時有發(fā)生。在船閘開始運行的半年中，在兩線船閘正常運行期間，有一定數(shù)量船舶滯留待閘，最高達252艘。尤其是在壩區(qū)流量超限、樞紐沖沙、客運高峰、船閘應(yīng)急搶修和計劃性停航期間，大量待閘船舶在三峽壩區(qū)滯留，最高達349艘。

目前，據(jù)官方數(shù)據(jù)顯示，2008年，三峽船閘運行8661閘次，通過55351艘次，通過貨運量5370萬噸，翻壩運量1477萬噸，過壩貨運量合計6847萬噸。三峽船閘待閘時間4～10小時，過閘時間約3.5小時。三峽下行過閘貨運量和下行過壩貨運量分別為3259萬噸和4013萬噸，是三峽船閘設(shè)計通過能力的65%和80%。據(jù)有關(guān)研究機構(gòu)預(yù)測，2020年、2030年三峽樞紐斷面下行貨運量將分別達到6315萬噸、7750萬噸。而三峽船閘設(shè)計單向通過能力為5000萬噸。從長遠看，即使考慮今后三峽升船機投入使用，三峽現(xiàn)有通航建筑物也難以滿足船舶過壩需要。

在《長江三峽水利樞紐初步設(shè)計報告（樞紐工程）》中，已經(jīng)提到當三峽工程通航建筑物不能滿足通航需要時，要考慮建設(shè)新的過船通道。三峽工程五級船閘于1994年4月開工，2003年6月試通航，2007年5月船閘工程全面竣工，工程建設(shè)前后歷時13年。加上規(guī)劃、勘測、科研和設(shè)計時間，三峽船閘建設(shè)經(jīng)歷的時間更長。在三峽通航建筑物通過能力不能滿足通航需要前，應(yīng)預(yù)先研究并建設(shè)三峽大壩新的船舶通道，并應(yīng)留足工程建設(shè)前期工作時間和建設(shè)時間。

據(jù)了解，目前三峽新船閘的建設(shè)方案已經(jīng)進入了研究階段，而先期被停建的三峽升船機已于2008年9月開始續(xù)建，金屬結(jié)構(gòu)制造安裝正在招標，計劃在2015年6月建成運行。同時，三峽翻壩公路也正在建設(shè)之中，有專家指出，提高三峽樞紐綜合通過能力和翻壩運輸效率，應(yīng)該調(diào)整原來的“水-陸-水”為“水-陸”運輸方式，目前，長江右岸正在建設(shè)翻壩運輸高速公路，該公路上起姊歸曲溪橋，經(jīng)過姊歸縣、夷陵區(qū)等，止于宜昌長江公路大橋南岸，連接滬渝高速公路，全長57.38公里，于2010年底建成。同時，翻壩碼頭也正在緊鑼密鼓地建設(shè)中。三峽壩上右岸已建碼頭有茅坪港客運碼頭、靖江溪滾裝碼頭，左岸有太平溪港客運碼頭、姊歸物流中心滾裝碼頭。兩壩間已建碼頭包括右岸岱獅滾裝碼頭，左岸楊家咀滾裝碼頭，黃柏河水域平湖滾裝碼頭和夜明珠滾裝碼頭。

據(jù)統(tǒng)計，2009年，通過三峽樞紐斷面貨運量7425萬噸，其中通過船閘6089萬噸，翻壩運輸1336萬噸。預(yù)測2020年通過三峽樞紐斷面貨運量約1.3億噸，其中通過船閘和升船機1.1億噸，翻壩運輸2000萬噸。

水庫群聯(lián)合調(diào)度

長江上游干支流是我國水電能源集中地區(qū)，金沙江、雅礱江、烏江、岷江、大度河、嘉陵江等干支流陸續(xù)進行了水電建設(shè)開發(fā)，結(jié)合已經(jīng)建成的三峽、葛洲壩水利樞紐，長江干支大型水庫群將陸續(xù)形成。

由于長江上游干支流水庫分屬不同業(yè)主管理，大都按單庫運行方式或某一支流級水庫聯(lián)合運行方式運行，這將制約三峽工程和上游水庫綜合效益綜合的發(fā)揮。專家建議長江干支大型水庫群應(yīng)進行聯(lián)合調(diào)度，從而更合理地安排水庫群的蓄、泄水時機，協(xié)調(diào)興利與防洪、生態(tài)的關(guān)系。同時，上游水庫群聯(lián)合調(diào)度后，梯級水庫可進行補充調(diào)節(jié)，三峽水庫可較長時間維持在高水位運行，枯水期對下游補償量增大，航道水深增加，對保障航運效益的正常發(fā)揮將起到較好作用。

當然，水庫蓄水給庫區(qū)航道帶來益處的同時，在長江干支流的高等級航道中，水庫群依然礙航斷航現(xiàn)象也不容忽視。細數(shù)下來，令人痛心。在烏江上，除彭水外其余梯級未同步建設(shè)通航設(shè)施，造成斷航。沅水航道規(guī)劃為500噸級，但白市、托口梯級升船機為通航50噸船舶，洪江梯級通航設(shè)施為300噸級。掛治梯級未建通航設(shè)施。漢江，丹江口升船機無法正常運行。贛江通航規(guī)劃為1000噸級，但萬安梯級通航設(shè)施為500噸級。信江的界牌樞紐蓄水位未達設(shè)計標準，造成船閘坎上水深不足，同時紅衛(wèi)壩樞紐未按要求拆除。錢塘江航道規(guī)劃為500噸級，富春江船閘只能通過100噸級船舶。

多年來，閘壩礙航，與跨江橋梁凈高過低一樣，是長期困擾著內(nèi)河航運的典型性問題，已成為長江通過能力的硬傷。既然是硬傷就很難在朝夕之間就可以解決，然而，硬傷背后所反映的，更多的是軟環(huán)境的不足所帶來的直接后果。在長江大力加快提高航道等級的同時，長江船舶的通過能力要切實找到著力點，還需要更多內(nèi)河軟實力的提升。

In March 2011, the Ministry of Transport issued “Advice on implementation of the State Council’s Opinions on accelerating the development of inland water transport including Yangtze River”, marking that China has started to put into practice the development plan. However, a fact that can not be ignored is that impeding navigation problems such as bridges and gate dams will be more outstanding when speeding up waterway dredging.

Elevating cross-river bridges without suff i cient headroom

Yangtze River fl ows into the East China Sea and thanks to its abundant water received from tributaries and lakes,was navigable by ocean-going vessels. In 1931, the 10,000-ton US tanker “California” made her way up to Wu Han directly from its mouth. At present, however, vessels of ten thousand tons intending to make a river-sea voyage are subject to the height of cross-river bridges.allow the ship of 3,000 tons to pass through. Due to the restriction of built bridges, the 213km deep water route from Nanjing to Tongling, which is navigable by sea-going vessels of 10,000 tons, has not been fully utilized. Too low headroom under bridges has become the bottleneck of thoroughfare for sea logistics from the middle and upper reaches of Yangtze River.

Currently, there are more than 60 cross-river bridges along Yangtze River Trunk Line, among which 11 bridges in the middle-lower reaches of the river usually have net height of 24 meters for navigation, and could allow the ships of 5,000 tons or 10,000 tons to pass through, while 41 bridges in the middle-upper reaches of the river usually have net height of 18 meters for navigation, and could

According to Xu Guang, Chief Engineer of Chinese Ministry of Transport, the study has shown that the economically reasonable transport route for sea-going vessels of 10,000 tons is direct navigation up to An Qing.Consequently, the long-term development of Yangtze River shipping requires elevation of the spanning and headroom standards for the newly built river-crossing bridges from An Qing down to the lower reaches of the river. According to experts, currently there are several methods of raising the height of bridges .Firstly, heighten piers to raise the bridge girder. Secondly, renovate bridges to turn one of apertures of the bridge into movable bridge. Some bridges over the Rhine have adopted this method. Thirdly, turn road and rail dualpurpose bridges into dedicated road service bridge, and dismantle sublayer bridge for railway service to increase the headroom. In addition, large standard vessels to be built should accommodate existing bridges’ span.

Upgrading capacity and efficiency of three gorges project

The Three Gorges project has multiple benefits ranging from flood prevention to electricity generation and shipping. However, since the damming of the great river in 1997, the shipping on Yangtze River Trunk Line has gone through all kinds of trials and tribulations. From open channel to temporary lock, Three Gorges has obvious def i ciencies in terms of navigation capacity. To solve this problem, the phenomenon of passing through the dam by road started to appear in 1998, which was a temporary action due to lack of alternative during construction of Three Gorges. However, even though the two-way fivestep lock of Three Gorges put into service on 15thJune,2003 and Yangtze River was open to normal navigation,the means of passing through the dam by road still played an important role in transferring a large amount of goods and materials.

From the long term perspective, the existing navigation buildings of Three Gorges are diff i cult to meet the demand of ships to pass through the dam, even considering the future use of ship lift. At present, the earlier suspended construction of Three Gorges ship lift began to be resumed from September 2008. The bidding for metal structure and manufacturing installation is in the process,and the ship lift is planned to be completed and put into service by June 2015. Meanwhile, Three Gorges roads used for transferring goods are also under construction.Some experts point out that the original transportation mode of “water-land-water” should be adjusted to “waterland” by increasing the overall transit capacity of Three Gorges Dam and improving the efficiency of passing through the dam by road. According to the statistics, the cargo volume passing through Three Gorges section was 74.25m tons in 2009, of which 60.89m tons passed through ship lock and 13.36m tons by transferring to road.It is predicted that the cargo volume of Three Gorges section will reach 130m tons by 2020, of which 110m tons will pass through ship lock and lift and 20m tons by transferring to road.

Consolidated management of reservoir group

Main streams and tributaries of the upper Yangtze River give rise to China’s major water and hydroelectric resources. Jinsha River, Yalong River, Wujiang River,Minjiang River, Dadu River and Jialing River successively started hydroelectric constructions, which, together with Three Gorges and Gezhouba Dam that have been built,will lead to gradual formation of large reservoir groups in the main streams and tributaries of the Yangtze River.

Since the reservoirs in the main streams and tributaries of the Yangtze River belong to different owners, most of them are being run in the form of single reservoir or joint reservoir operation in the same tributary, which will restrict the overall efficiency of the Three Gorges project and upstream reservoirs. Experts suggest that the reservoir groups in main streams and tributaries of the Yangtze River should be managed in union, so that the timing of water storage and fl ood discharge could be scheduled more reasonably, and the relations among water conservancy, flood control and ecology could be coordinated. Meanwhile, when reservoir groups in the upper reaches implement joint management, step reservoirs could be replenished and regulated, the Three Gorges reservoir could maintain its operation at high water level for a extended period and thus increase water supply to the lower reaches in dry seasons, and the depth of navigation route could also be increased, all of which will help promote shipping eff i ciency of the river.

Decoding the“Locked” Golden Channels

Reporter Xu Hua