临海浅埋富水地层明挖隧道抗浮稳定性研究

Floatation-resistant stability of open excavation tunnels in offshore shallow stratum

根据港珠澳大桥珠海连接线的关键控制工程拱北隧道的特点,对海域明挖基坑深度较浅段落,通过建立三维复杂数值计算模型,考虑桩土的相互作用,模拟抗拔桩的实际负摩阻力工作机理,分析了抗拔桩在不同参数方案下的变形和受力特征,得到以下结论:1考虑底板抗拔桩不同参数方案,抗拔桩在底板抵抗扬压力上浮时发挥的作用显著,能有效的降低底板隆起最大值;2增加桩长和桩径都能够有效提高抗拔桩提供的抗浮效果,增加抗拔桩的桩长在控制底板在扬压力作用上浮隆起效果更加显著;3抗拔桩的不同参数对连续墙的水平位移以及地表沉降槽的影响很小,抗拔桩对抵抗基底隆起的作用比较大。

According to the characteristics of the key project, Gongbei tunnel of Zhuhai connecting line of Hong Kong-Zhuhai-Macao Bridge, a three-dimensional numerical model is established. The working mechanism of uplift piles is simulated for the shallow part of open excavation ditch considering the interaction between the piles and the soils. The characteristics of deformation and stress of the uplift piles are analyzed according to different parameters and concepts. Some conclusions are drawn.