跨江特大桥旋挖钻孔灌注桩入海口水上施工实践

Over-water Construction Practice of Rotary Bored Grouting Pile at the Estuary of Oujiang River

以温州市市域铁路灵昆特大桥北岸工区钻孔灌注桩施工为工程实例,对旋挖钻机在跨江入海口水上钻孔施工中,遇到的强潮海区,钻孔桩深度较大,上部有流塑性地层极不稳定,桩底要伸入卵石层较深且卵石层存在急性漏浆情况,受潮汐影响很容易造成塌孔等重点难点所采取的技术措施及工程效果进行了分析与探讨。

With the engineering ease of bored grouting pile construction in the work area at north band Of Lingkun bridge for Wenzhou regional railway, the analysis and discussion are made on the technical measures adopted to overcome difficulties of rotary drilling rig construction in over-water holing at the estuary and the engineering effects. The difficulties are involved as strong tidy sea area encountered, large depth of bored pile, very unstable flow plastic formation at the upper part, the pile bottom extending deep into the pebble layer with sudden mud leakage possibility and hole collapse easily caused by tidal effect, and so on.