A Bridge that Connects the Mountains with the Plain

Profile of the bridge prior to its completion合龍前的大橋一側(cè)

The steel girders of the Chibi Yangtze Highway Bridge赤壁長江公路大橋的鋼箱梁

在湖北省咸寧市三國赤壁古戰(zhàn)場上游5 公里處，一座雄偉的跨長江大橋——赤壁長江公路大橋，2021年3月16日順利合龍。

大橋建成通車后，將成為武漢城市圈和長江經(jīng)濟帶重要的過江通道，從地跨湘鄂贛的幕阜山區(qū)到江漢平原，一步到達(dá)，將推動片區(qū)社會經(jīng)濟快速發(fā)展，成為推動湖北長江經(jīng)濟帶發(fā)展的交通“硬支撐”。

一座大橋，承載半個世紀(jì)的期盼

赤壁，一個記載著千年厚重歷史的城市，三國赤壁之戰(zhàn)曾經(jīng)發(fā)生在這里。如今，當(dāng)年火燒赤壁遺跡歷歷在目。

萬里長江蜿蜒流淌，滋養(yǎng)著赤壁這片美麗的土地，卻也阻隔了兩岸出行和經(jīng)濟發(fā)展。擁有128 公里長江岸線的咸寧卻沒有一座跨江大橋，是湖北省沿江城市中唯一沒有跨江大橋的地級市。修建跨越天塹的長江大橋，成為兩岸百姓多年的企盼。

2014年，國務(wù)院通過《長江經(jīng)濟帶綜合立體交通走廊規(guī)劃》，嘉魚和赤壁長江大橋雙雙列入長江干線新建過江通道重點項目。湖北交投集團(tuán)主動請纓投資建設(shè)，咸寧跨長江大橋的夢想終于成真。

5 kilometers (about 3 miles)upstream of the ancient battlefield of the Three Kingdoms in Chibi,Xianning City,Hubei,the Chibi Yangtze Highway Bridge in all its grandeur spans across the Yangtze River,with its closure completed on March 16,2021.

After the bridge completes its construction and opens to traffic,it will become an important passageway across the Wuhan City Circle and the Yangtze River Economic Belt.It will enable smooth traverse from the Mufu mountainous area across Hunan,Hubei,and Jiangxi to the Jianghan Plain,expediting the social and economic development of the area and promoting the development of the Yangtze River Economic Belt with“infrastructural support” in Hubei transportation.

Half a century of hopes pinned on a single bridge

Chibi,a city with a thousand years of history,is where the famous Battle of Red Cliff took place in the Three Kingdoms Period (220-280).Today,the charred remains of Chibi are still freshly smoldering the collective consciousness of the people of the region.

The Yangtze River meanders for thousands of miles and nourishes the lush and lavish land of Chibi,but it also obstructs travel and economic development on both sides of the river.Xianning,which is home to 80 miles of Yangtze River shoreline,does not have a single bridge connecting the two shores.It is the only prefecture-level city along the river in Hubei Province that is impossible to cross without a boat.The construction of this bridge linking both sides of the river is long-anticipated by residents.

In 2014,the State Council approved the Comprehensive Plan for the Transportation Corridor of the Yangtze River Economic Belt,and the Jiayu and Chibi Yangtze River Bridges were both included in the key projects of the newly-built Yangtze River main line.The Hubei Communications Investment Group Co.,Ltd.volunteered to invest in the construction,and the dream of a bridge connecting Xianning had finally come true.

On March 21,2018,the sound of rumbling along the vast expanse of the Yangtze broke the calm serenity of the ancient battlefield that hearkens back to ancient clashes that took place more than 1800 years prior.The Chibi Yangtze Highway Bridge project officially broke ground that day.The dream of the Chibi Bridge that the people of Xianning had held so near and dear to their hearts for half a century had been made manifest.

Homegrown technology has made for a worldclass bridge

With a main span of 720 meters(2,400 feet),the Chibi Yangtze Highway Bridge is the world’s longest steel-concrete composite cable-stayed bridge in terms of span length.Experts believe that a breakthrough has been achieved in the main span of this bridge type,which has been effectively elongated from 1,900 to 2,400 feet with the closure of the Chibi Yangtze Highway Bridge.This has greatly enhanced the development of bridge-building technology and provides Chinese design and construction solutions for bridges all across the world.

The geological conditions at the bridge construction site are highly convoluted.The foundation is located on a limestone bedrock,from which karst caves are formed,the biggest of these is 51 feet.There are often water leakage and collapses during construction.The nature of the rock strata is poor,making it difficult to drill the foundation.

April 2020,the completion of the main pylons of the Chibi Yangtze Highway Bridge2020年4月，赤壁長江公路大橋主塔封頂

2018年3月21日，一望無際的長江岸邊，隆隆的打樁聲劃破古戰(zhàn)場1800 多年的平靜，赤壁長江公路大橋正式開工，咸寧人民追求半個世紀(jì)的赤壁大橋夢成為現(xiàn)實。

技術(shù)植入，進(jìn)入世界橋梁殿堂

主跨720 米！赤壁長江公路大橋是世界最大跨徑鋼混結(jié)合梁斜拉橋。相關(guān)專家認(rèn)為，這一橋型的主跨實現(xiàn)由600 米級向700 米級突破，極大地推動橋梁技術(shù)發(fā)展，為世界橋梁提供了中國設(shè)計和建設(shè)方案。

赤壁長江公路大橋的橋址地質(zhì)條件復(fù)雜，樁基位于灰?guī)r區(qū)，溶洞發(fā)達(dá)，最大洞高15.8 米，施工常有漏水、塌陷現(xiàn)象，巖層性質(zhì)差，樁基成孔難度大。

難，還在鋼混結(jié)合梁的安裝。整座大橋“骨架”由121 個主鋼混梁組成。每片主鋼梁包括2 根箱型主梁、3 根橫梁、1 根縱梁和混凝土主橋面板，每個混梁重500 多噸，涉及多項復(fù)雜工藝，還要與斜拉索安裝環(huán)環(huán)相扣，且每個“龐然大物”之間對接精度在3 毫米內(nèi)。

作為大橋的主要受力結(jié)構(gòu)，斜拉索安裝是大橋建設(shè)的重要一環(huán)。赤壁長江公路大橋共設(shè)116 組232根斜拉索，采用鋼絲強度達(dá)到1860兆帕。斜拉索單根最長387.21 米，最大重量38.49 噸。纜索的“穿針引線”也不輕松。“線”是一根重幾十噸的斜拉索，里面綁著253 根鋼絲，“針”是大型吊機，從223米高的主塔“穿”下來。工人在高空用張拉錨桿、卷揚機將盤卷的斜拉索吊起，把索頭固定在主塔。索的另一頭在橋面，用10 多個滑輪牽引，在吊機配合下將索穿進(jìn)錨拉管。工人們穿一根“線”，要連續(xù)干3 小時。

承建單位是世界建橋?qū)嵙ε伞需F大橋局，團(tuán)隊加強技術(shù)攻關(guān)，實現(xiàn)了多項重要技術(shù)創(chuàng)新。在赤壁長江公路大橋上，兩片主梁安裝時間為12 天，比采用傳統(tǒng)工藝縮短4 天，吊運一片梁比原來縮短3 小時，創(chuàng)造了“赤壁橋速度”。

大橋主塔采用“H”形設(shè)計，北主塔高217.33 米，南主塔高223米。項目創(chuàng)新設(shè)計方式，工藝工法創(chuàng)新取得了多個“世界第一”，攻克了大體積承臺混凝土澆筑、超高主塔混凝土一次性垂直傳輸、大跨徑720 米鋼混結(jié)合梁索力和成橋線型控制等多項世界難題。

The bridge being outfitted with box girders建設(shè)中的赤壁長江公路大橋正在調(diào)裝箱梁

Despite the difficulties,the installation of steel-concrete composite beams goes on as planned.The “framework” of the entire bridge is composed of 121 main steel-concrete beams.Each main steel-concrete composite girder includes two box-type main girders,three cross girders,one longitudinal girder and a concrete main bridge deck.Each composite girder weighs more than 500 tonnes and involves a host of complicated processes,and also requires installation with cable stays that interlock to 3-mm accuracy between each massive beam.

As the main stressed structure of the bridge,the installation of the stay cables is an important part of the construction.The Chibi Yangtze Highway Bridge has a total of 116 sets of 232 stay cables,with steel wire strength reaching 1860 MPa.The longest single-stay cable is 1,270 feet and the maximum weight is 38.49 tonnes.The “needlework” that fastens the cables is not easy,as the stayed cable weighs more than ten tonnes,and has 253 steel wires tied inside.The “needle”itself is a large crane that “sews”from the 730-foot-high main pylon.Workers use a tension anchor rod and crane to hoist the coiled stay cables to their soaring heights and fix the cable head to the main pylon.The other end of the cable is on the bridge deck,and it is towed by more than 10 pulleys.With the crane working in complete concert with the workmen below,the cables are inserted one by one into the anchor pipe.Workers “thread”nonstop for three hours to get each cable through.

The organization responsible for the construction is China Railway Bridge Bureau,a worldleading bridge construction group.The team has been bolstering its technical research and as a result,made a number of important technical innovations.On the Chibi Yangtze Highway Bridge,the installation time of the two main beams was 12 days,four days shorter than with existing technology.Meanwhile,the time taken to lift one beam was shortened by three hours,giving rise to something now affectionately called,“Chibi Bridge Speed.”

The main pylon of the bridge was formed into an H shape,the north pylon is 710 feet high,and the south pylon is 730 feet high.The innovations in design and technology for this project have achieved a laundry list of world firsts,and have overcome problems that have plagued bridge builders the world over,i.e.,large-volume pile cap concrete pouring,superhigh main pylon one-time vertical concrete transference,cable force of large-span 2,400-foot steel-concrete composite beams,and bridge linear control.(Translation:Chase Coulson)

The completion of Chibi Yangtze Highway Bridge赤壁長江公路大橋合龍現(xiàn)場

The construction site in full swing施工現(xiàn)場熱火朝天