6.14 Earthquake modeling

Simulation of soil liquefaction

A shaking table test on saturated sand was conducted under a 50 G environment to study soil liquefaction. A photograph of the model is shown in Fig. 1. Saturated sand overlying on the bottom stiff layer was tested in a laminar container (Fig. 2). The model was 100 cm long, 30 cm wide and 30 cm deep. 50 CS silicon oil was used as pore fluid to match the time scales of diffusion during the shaking.

The package was placed on the shake table in the centrifuge and brought up to 50 G centrifugal acceleration. A photograph of a model on the platform of the centrifuge is shown in Fig. 3. An input acceleration which was 20 sinusoidal waves with a frequency of 140 Hz was applied to the model.

Accelerations and pore pressures were recorded during the test. The locations of accelerometers and pore pressure meters are given in Fig. 5.

The typical records of acceleration and pore pressure are shown in Fig. 6. During the test, the pore pressure increases in the layer of saturated sand and the amplitude of acceleration decreases. The results show that the layer of saturated sand actually liquefied.

Fig. 1 A photograph of the model

 

Fig. 2 A photograph of the laminar container

 

Fig. 3 A photograph of the model on the platform

 

Fig. 4 A photograph of the shaking table

 

Fig. 5 The locations of accelerometers and pore pressure meters

 

Fig. 6 The typical records of acceleration and pore water pressure

 

No reference but the tests conducted by Nishimatsu Co.