With the large-scale development of ocean engineering, it becomes common to encounter the existing submarine pipelines in pile driving area. In this paper, based on a pier berth reconstruction project, threedimensional (3D) numerical models taking into account the pore water effect are presented to investigate the influence of large-diameter pipe pile driving on adjacent submarine pipelines. Extensive numerical studies are conducted to investigate the effect of the minimum plane distance of pile-pipe on the relative displacement of pipe-soil and the excess pore water pressure of surrounding soil around the pipe at different pile driving depths.
The precast pile foundations are widely used to support the structures resting on soft and compressible soils due to its easy quality guarantee, stable bearing capacity and high construction efficiency. Yet, the soil lateral displacement, ground vibration and excess pore water pressure induced by pile installation have serious implications on the surrounding buildings (Linehan et al., 1992; Wong and Chua, 1999; Svinkin, 2004; Lu and Yeung, 2011; Dezi et al., 2013; Su et al., 2016), which are commonly studied through the in-situ measurements. However, the cost of in-situ measurement is high and the simple in-situ measurement would lead to construction risks (Su et al., 2016).
The method of hammering construction is suited to the large diameter offshore pile foundation due to its cost-effectiveness. With the large-scale development of ocean engineering, an increasing number of submarine pipelines (water and oil-gas pipeline) and offshore structures (high-pile wharves, wind turbines and drilling platforms) are being built. Thus, it becomes common to encounter the existing submarine pipelines near the construction site of pile driving. It is more difficult to predict the influence on submarine pipelines caused by pile driving in comparison with that on onshore structures. Thus, in order to better investigate the impact of pile driving on adjacent submarine pipelines, the numerical analysis method is resorted to, which can avoid the disadvantages of in-situ measurements. However, most previous literatures relevant to the simulation of pile driving merely focus on the impact on the surrounding soils (Mabsout et al., 1999; Segaseta and Whittle, 2001; Masoumi et al., 2009; Henke and Grabe, 2009; Fu and Lou, 2011; Khoubani and Ahmadi, 2012; Osinov et al., 2013), and little attention has been taken on the impact on the adjacent structure (Li and Zhou, 2007; Grabe, et al. 2009; Henke, 2009; Guo, et al. 2014), especially on the submarine pipeline (Su et al., 2016). The soil lateral displacement, ground vibration and excess pore water pressure induced by pile driving can result in the deformation of adjacent concrete pipelines, and even cause pipe crack.
