吉图珲铁路第二松花江特大桥水中墩承台施工技术

Construction Technique of the Bearing Platform above Water for the 2nd Songhua River Grand Bridge on the Jituhun Railway

吉图珲铁路第二松花江特大桥主桥采用（55.75＋96＋96＋55.75）m预应力混凝土连续箱梁,桥址处覆盖层浅、透水且富含大直径漂石,承台入弱风化岩层1.1~2.7m,岩面倾斜,受桥位处航道水深限制和下游既有长图铁路老桥的影响,承台不能提高,也不能进行水下爆破。通过方案比选,最终确定了静压植桩机插打钢板桩围堰施工方案。实践表明,该施工方案较好地克服了各种不利因素的影响,在汛期来临前顺利地完成了水中墩承台施工。

The 2nd Songhua river grand bridge on the Jituhun Railway, whose main bridge is（55.75＋96＋96＋55.75）m pre-stressed concrete continuous box beam, is located on the shallow pervious coverage with big boulders. Its bearing platform is under the sloping moderate weathered rock formation for 1.1m-2.7m. Because of the channel depth and the old Changtu railway bridge on the downstream, the bearing platform can not be lifted or underwater blasted. After the scheme comparison, the construction scheme of inserting steel sheet pile cofferdam by static pressure pile driver is determined. It is proved to have conquered various disadvantages and successfully finished the construction of the bearing platform above water before flood season.