摘要
安庆长江铁路大桥主桥为主跨580m的连续钢桁梁斜拉桥,该桥3号、4号桥塔墩基础采用双壁钢围堰施工,钢围堰外径56m、壁厚2m,总高分别为42.88m和41.4m。为满足通航净空要求,承台面以上钢围堰需全部拆除。主桥完工后,在枯水期,沿承台面拆除钢围堰,拆除高度22.38m,在高度上分2节、平面上分16块拆除,按自下游向上游方向进行拆除。钢围堰拆除时,先在围堰内开设切割通道,然后按先竖缝、后水平缝的顺序切割,最后切割隔舱板和顶部连接处。水面以上钢围堰均采用常规氧气法切割;水面以下围堰内无沉积物时,直接采用水下氧-弧切割法切割钢围堰;由于3号墩钢围堰内有较多沉积物,先抽水,割开围堰内壁板,将围堰内沉积物凿除后,再灌水,进行水下切割。
The main bridge of Anqing Changjiang River Railway Bridge is a continuous steel truss girder cable‐stayed bridge with a main span of 580 m .The foundations for the pylon piers No .3 and No .4 of the bridge were constructed ,using the double‐wall steel cofferdams that had the external diameters of 56 m ,wall thickness of 2 m and total height respectively of 42 .88 m and 41 .4 m .To accord with the navigational clearance requirements ,the parts of the cofferdams above the pile cap tops should be completely demolished after the main bridge was constructed .In the demol‐ishing construction ,the cofferdams were demolished along the pile cap tops in the low water period and the demolishing height of the cofferdams was 22 .38 m .In the height ,the demolished part of a cofferdam was divided into 2 tiers and in the plan ,was divided into 16 segments and the demolis‐hing was carried out from the downstream side to the upstream side of the river .When the coffer‐dams were being demolished ,the cutting accesses were firstly opened up in the cofferdams ,the cutting then proceeded in the sequence of cutting the vertical joints first and the horizontal joints late and finally the bulkheads and the connections at the tops of the cofferdams were cut .The parts of the cofferdams above the water were cut ,using the common oxygen cutting method and for the parts of the cofferdams with no sediment below the water ,the parts were cut ,directly using the underwater oxygen‐arc cutting method .Since the considerable amount of the sediment existed in the cofferdam of the pylon pier No .3 ,the water in the cofferdam was firstly pumped out ,the inner wall plates of the cofferdam were cut apart ,the sediment was chiseled off and the water was then pumped in and the underwater cutting was continuously carried out .
出处
《桥梁建设》
EI
CSCD
北大核心
2016年第5期1-5,共5页
Bridge Construction
关键词
高速铁路桥
斜拉桥
钢围堰
拆除
水下切割
凿除
桥梁施工
high-speed railway bridge
cable-stayed bridge
steel cofferdam
demolishing
underwater cutting
chiseling off
bridge construction
