Experimental investigation on the wave-induced pore pressure around shallowly embedded pipelines

A series of regular wave experiments have been done in a large-scale wave flume to investigate the wave-induced pore pressure around the submarine shallowly embedded pipelines.The model pipelines are buried in three kinds of soils, including gravel, sand and silt with different burial depth.The input waves change with height and period.The results show that the amplitudes of wave-induced pore pressure increase as the wave period increase, and decay from the surface to the bottom of seabed.Higher pore pressures are recorded at the pipeline top and the lower pore pressures at the bottom, especially in the sand seabed.The normalized pressure around pipeline decreases as the relative water depth, burial depth or scattering parameters increase.For the silt seabed, the wavelet transform has been successfully used to analyze the signals of wave-induced pore pressure, and the oscillatory and residual pore pressure can be extracted by wavelet analysis.Higher oscillatory pressures are recorded at the bottom and the lower pressures at the top of the pipeline.However, higher residual pressures are recorded at the top and the lower pressures at the bottom of the pipeline.