Seismic response of mitigation of sand liquefaction beneath existing buildings using microbial induced desaturation

Abstract

Earthquake-induced liquefaction is a geological disaster that caused extensive damage to buildings, railways, dams. Due to the construction techniques and economic conditions, the subsurface layers of some buildings must be reinforced to resist seismic loads. Microbial-induced desaturation is a development technique which can be used for existing buildings to mitigate liquefaction. Shaking table tests were conducted to survey the effect of microbial induced desaturation on liquefaction-prone foundations beneath buildings. The test results showed that, lower saturation degree delays the generation of excess pore pressure and reduces its magnitude. It appears that the resistance to excess pressure increases as saturation degree is reduced from 100% to 93.4% or 85.6%. Desaturation prevents the decay of the amplitude of acceleration oscillations, but increases the accelerations of the structure. The settlement of the sandy soil decreases as the saturation degree decreases. Resistance to liquefaction increased by more than twice than that in the saturated sample after induced desaturation to 93.4%. The weight of the building structure contributes to the anti-liquefaction capacity.

Keywords

• Desaturation
• Microbial bubbles
• Three-storey frame structure
• Six-storey frame structure
• Shaking table test