An Experimental Study of the Distance Effect Away from Earthquake Fault on the Soil Deformation Characteristics

Many disaster investigations after significant earthquakes have indicated that the extent of damage is not simply related to the distance from the epicenter. Serious destruction has been found in the near-fault zones, as significantly affected by the distance from the earthquake fault. This study discussed the effect of ground motions from different fault distances under dynamic triaxial compaction tests. Five real ground motions were applied as observed by stations located at different distances from the earthquake fault caused Taiwan Chi-Chi Earthquake in 1999. This study also considered variable initial radial pressures (100 kPa, 200 kPa, and 400 kPa) and the consolidation ratio. The results indicate that both the maximum strain appearing during the dynamic load test and residual strain by near-field shaking are significantly greater than those in other fault distances. Generally, the closer to the fault, the greater the strain. The difference decreases as the initial confining pressure increases. This trend could be obtained under different consolidation ratios. However, the difference becomes more evident under anisotropic initial confining pressures.