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The shake table test for the tunnel-soil-pile interaction (TSPI) model under the uniform and seismic excitations is an innovative technology. This research presents the shake table test of the TSPI model for the dry and wet conditions of the Sylhet and local sand in Bangladesh under the sinusoidal wave, Kobe, and Loma Prieta seismic excitations. The relative densities for the local sand are 27%, 41%, and 55%, and for the Sylhet sand are 48%, 64%, and 80%. The sinusoidal wave frequencies of 1 Hz, 3 Hz, 5 Hz, and 7 Hz are used for the peak ground acceleration (PGA) of 0.05g, and the PGA for all ground motions are 0.05g, 0.10g, 0.15g, and 0.20g. The 3D numerical analysis of the TSPI model has been performed by utilizing the Plaxis 3D considering Mohr-Coulomb and UBC3D-PLM models of sand. The linear elastic model is considered for the tunnel, pile, and pile cap during the numerical analysis in addition, analytical formulations are developed for the TSPI model to consider the simplified single-cycle form of the sinusoidal wave. The dynamic and seismic excitations are applied at the base of the TSPI model along the transverse direction of the tunnel. The shake table has been properly calibrated before the start of the test. The numerical analysis is validated with the previous studies. The proposed analytical formulae have been also compared to the previous analytical formulations for a particular case. The calibration and validation results are found to be within an acceptable range. In some of the cases, the numerical and analytical results vary due to the assumptions to develop the analytical formulations. The liquefaction condition exists for the Sylhet and local sand in Bangladesh for most of the cases based on the experimental study. The experimental liquefiable tunnel moment is found to be agreed with the numerical results. This variation lies within a range of (5~10) %. This difference in experimental and numerical results is considered to be a satisfactory level. In addition, the square root sum of squares (SRSS) and root mean square (RMS) variations of the moments and displacements are calculated from the experimental studies and their values are compared with the numerical results. The cyclic strain variations in the dry condition are higher than in the wet condition based on the experimental results because of the occurrence of liquefaction in the homogenous sand of the TSPI model. In this study, the geometry of the TSPI model is considered to be fixed to avoid complexity during the construction in the limited size of the shake table in the laboratory. |
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