Development of free-field and compliant base SPH boundary conditions for large deformation seismic response analysis of geomechanics problems

Earthquake-induced geohazards are natural disasters that have the potential to cause severe damage to infrastructure and endanger human lives. To mitigate these natural disasters, advanced computational methods capable of dealing with large deformation and failure of geomaterials have been developed for years. Among those methods, the Smoothed Particle Hydrodynamics (SPH) method has been demonstrated to offer great flexibility in handling a wide range of challenging geotechnical problems, involving large deformations and post-failure behaviour of geomaterials. However, despite some primary attempts, a proper SPH framework for modelling seismic responses has not yet been fully developed. One of the key reasons for this is the absence of appropriate SPH boundary conditions for wave propagation analysis in infinite porous media. To overcome this problem, this study proposed new SPH boundary conditions to enable the SPH method to efficiently analyse seismic responses of geomechanics problems with compliant-base and free-field boundary conditions, allowing successfully reproducing wave propagation and dissipation in an infinite ground domain. Comprehensive verification and validation of the SPH framework, integrated with the newly developed boundary conditions, demonstrate its effectiveness in simulating the earthquake-induced large deformations and failures of geotechnical engineering problems. This suggests that the proposed computational model offers a robust tool for predicting and understanding the seismic response and associated large deformations, thereby advancing applications in geotechnical engineering and disaster risk mitigation.