2012年9月上第41卷第372期
施工技术
CONSTRUCTIONTECHNOLOGY
土耳其Izmit海湾大桥主塔基础设计与施工构思
刘宗华
（中铁大桥局集团第一工程有限公司，河南郑州450053）
[摘要］土耳其Izmit海湾大桥投标设计为一座主跨1550m的双钢塔3跨悬索桥，为双向6车道高速公路桥梁。桥址位于地震活动频繁的深海海湾地带，对桥梁抗震能力提出了更高要求。两主塔位于马尔马拉海中，采用钢管桩加固后的地基上铺填碎石垫层的钢筋混凝土沉箱基础方案，有效地解决了地震产生大的水平位移间题。施工方
案中，主塔基础采用水下地基加固处理、沉箱岸上组拼整体滑移下水浮运等创新思路。【关键调】桥架工程；悬索桥；主塔；基础；沉箱；设计；施工技术
[中图分类号］TU476；U448.25
【文献标识码］A
【文章编号】1002-8498(2012)17-0011-03
TheConceptionofMainTowerFoundation
DesignandConstructionforIzmitBayBridgeinTurkey
Liu Zonghua
(The First Engineering Co.,Lad.,MBEC,Zhengzhou，He'nan450053,China)
Abstract : The bidding design scheme of Izmit Bay Bridge in Turkey is three-span suspension bridge with double towers whose main span is 1 550m and it is a two-way six-lane highway bridge.The bridge is located in deep sea gulf region which is featured by frequent seismic activities. This condition demands the bridge to have very high antiseismic capacity. Both main towers are located in Marmara Sea. Reinforced concrete caisson strengthened by concrete filled steel tubular piles and paved with gravel cushions was adopted as the foundation scheme, which effectively solved the problem of big horizonta! displacement that earthquakes could cause. Some innovative ideas were used in the construction scheme, including underwater foundation strengthening for main towers foundation and slipping and floating transportation of caisson assembled onshore.
Key words: bridges; suspension bridges; main towers; foundations; caissons; design; construction
工程概况
拟建土耳其Izmit海湾大桥位于马尔马拉海（SeaofMamara）伊茨米特湾的最窄位置，北岸是 KaraBurun，南岸是HersekBurnu。桥位距伊斯坦布
尔50km，距安卡拉300km。 1.1桥式布置
在投标阶段主桥结构设计为（650+1550+ 650)m的3跨悬索桥，桥面宽38.4m，为双向6车道高速公路，设计行车速度120km/h。主塔基础采用钢管桩加固后并铺设碎石垫层的圆形沉箱基础，主塔采用高228m的箱形钢塔柱，为重力式锚锭，北锚采用明挖扩大基础，南锚扩大基础采用换填碎石加固处理，加劲梁采用钢箱梁，主缆设2根，单根主缆为127束5.5mm钢丝，主缆矢跨比为1/8.857。桥
【收蒋日期】2012-02-06
[作奢简介］刘宗华，工程师，E-msil：lb19992000@163，com 万方数据
式布置如图1所示。
北
650
1.550
图1主桥桥式立面布置（单位：m）
Fig.1 Elevation layout of main bridge(unit:m)
1.2建桥条件
4
11
1)水文、地质
：桥位最大水深约61.64m，北塔
（②号）墩位水深41m，南塔（③号）墩位水深38m 南锚（④号）处水深约2m，北锚啶（①号）位于岸上。拟建桥址场地覆盖层主要为第四纪海积地层，以黏性土为主，含砂、砾和粉土。
2)通航条件通航净空64m，桥梁所在位置有商业和军用船只通行。
3)地震影响桥址区地震活动强烈，可能有较