桥梁建设
橋樑建設
교량건설
BRIDGE CONSTRUCTION
2015年
1期
1-5
,共5页
铁路桥%斜拉桥%钢桁梁%基础%围堰%多功能平台%护筒插打%桥梁施工
鐵路橋%斜拉橋%鋼桁樑%基礎%圍堰%多功能平檯%護筒插打%橋樑施工
철로교%사랍교%강항량%기출%위언%다공능평태%호통삽타%교량시공
railway bridge%cable-stayed bridge%steel truss girder%foundation%cofferdam%multi-function platform%inserting and driving of steel casing%bridge construction
新白沙沱长江大桥主桥为（81＋162＋432＋162＋81） m钢桁梁斜拉桥，3号主墩基础为36根φ3．2m钻孔桩，承台尺寸为67．4m×31．3m×6m。综合考虑多种因素，3号主墩基础施工采用“水下控制爆破＋多功能平台＋双壁钢套箱围堰”的方案，水下爆破与多功能平台拼装同步作业，钻孔桩施工与双壁钢套箱围堰拼装双层作业、同步施工。采用乳化炸药进行水下爆破；多功能平台整体浮运，利用多点同步提升技术提升到位后，与渡洪桩共同形成钻孔平台；采用振动打桩机插打钢护筒；采用清水气举反循环成孔工艺施工钻孔桩；围堰拼装后，进行注水下沉、堵漏、抛填、封底施工，将下放平台改造成内支撑，最后进行抽水、承台施工。
新白沙沱長江大橋主橋為（81＋162＋432＋162＋81） m鋼桁樑斜拉橋，3號主墩基礎為36根φ3．2m鑽孔樁，承檯呎吋為67．4m×31．3m×6m。綜閤攷慮多種因素，3號主墩基礎施工採用“水下控製爆破＋多功能平檯＋雙壁鋼套箱圍堰”的方案，水下爆破與多功能平檯拼裝同步作業，鑽孔樁施工與雙壁鋼套箱圍堰拼裝雙層作業、同步施工。採用乳化炸藥進行水下爆破；多功能平檯整體浮運，利用多點同步提升技術提升到位後，與渡洪樁共同形成鑽孔平檯；採用振動打樁機插打鋼護筒；採用清水氣舉反循環成孔工藝施工鑽孔樁；圍堰拼裝後，進行註水下沉、堵漏、拋填、封底施工，將下放平檯改造成內支撐，最後進行抽水、承檯施工。
신백사타장강대교주교위（81＋162＋432＋162＋81） m강항량사랍교，3호주돈기출위36근φ3．2m찬공장，승태척촌위67．4m×31．3m×6m。종합고필다충인소，3호주돈기출시공채용“수하공제폭파＋다공능평태＋쌍벽강투상위언”적방안，수하폭파여다공능평태병장동보작업，찬공장시공여쌍벽강투상위언병장쌍층작업、동보시공。채용유화작약진행수하폭파；다공능평태정체부운，이용다점동보제승기술제승도위후，여도홍장공동형성찬공평태；채용진동타장궤삽타강호통；채용청수기거반순배성공공예시공찬공장；위언병장후，진행주수하침、도루、포전、봉저시공，장하방평태개조성내지탱，최후진행추수、승태시공。
The main bridge of the New Baishatuo Changjiang River Bridge is a steel truss girder cable‐stayed bridge with span arrangement (81+162+432+162+81) m .The foundation for the main pier No .3 of the bridge is the one that is comprised of 36 nos .of φ3 .2 m bored piles and the dimensions of the pile cap is 67 .4 m × 31 .3 m × 6 m .In comprehensive consideration of various factors in the construction ,it was determined that the foundation should be constructed by the scheme of the“underwater controlled blasting+multi‐function platform+double‐wall steel boxed cofferdam” .The underwater blasting was carried out in parallel with the assembling of the multi‐function platform .T he construction of the bored piles and the assembling of the double‐w all steel boxed cofferdam w ere carried out also in parallel in separated double levels .In the un‐derwater blasting ,the emulsion explosive was used .The multi‐function platform was integrally floated to the pier site ,was lifted in place ,using the technique of multi‐point and synchronous lifting and together with the flood controlled piles at the pier site , the boring platform was formed .The steel casings for the bored piles were inserted and driven by the vibration pile driv‐er .The holes of the bored piles were constructed by the method of clear water ail lifting and re‐verse circulating .After the cofferdam was well assembled ,the cofferdam was filled in with water and was ready to sink down ,the leakage in the cofferdam was stopped ,the cofferdam was rip‐rapped and backfilled and the base sealing of the cofferdam was constructed .The platform was then lowered down and transformed into the internal support and finally the water in the coffer‐dam was pumped out and the construction of the pile cap was carried out .
