Physical modelling of the interaction between a tunnel and a building in a liquefying ground and its mitigation

•in urban spacing tunnel & buildings can be so close to interact in liquefying soil.•such interference is mitigated by adding nanoparticles (laponite) to the sandy soil.•a horizontal layer of treated soil beneath the tunnel floor is ineffective.•a vertical barrier of treated soil between tunnel and building mitigate interaction.•temporary structures, as for cut-and-cover, may help in mitigating this interaction.