The 2nd Badong International Geohazards Symposium (BIGS2019)

51 / 2019-06-01 19:16:43

Assessment of dynamic compaction on mitigation of liquefaction hazards

soil liquefaction,dynamic compaction,random field models

Prevention and Control of Reservoir Geohazards and Ecological Environmental Protection > Geohazards prevention and control harmonious development of ecological environment

Soil liquefaction is one of the major geo-hazards triggered by an earthquake. It can cause lateral spreading, ground settlement, sand boiling, which in turn, may damage infrastructures and induce loss of life. Dynamic compaction (DC) has been found to be an effective technique to mitigate liquefaction hazards, as evidenced by the improved ground performance in resisting liquefaction during past earthquakes. This presentation shows the findings of a case study on a reclaimed ground, where cone penetration tests were conducted before and after DC and where liquefaction manifestation was observed in the 1999 Chi-Chi earthquake. Through the case study, the effect of DC on mitigating liquefaction hazards was assessed from a probabilistic perspective and a random field perspective. It’s found that the effect of DC is observed not only on the increase in the soil strength, but also on the reduction in the variation of soil strength. The first effect is well recognized but later one is seldom reported. Furthermore, to overcome the challenges in comparison of the liquefaction potential before and after DC, a random field-based approach was proposed to visualize and quantitatively evaluate the effectiveness of DC across the entire project site. This approach is proven effective in assessing the effects of DC and is validated with liquefaction observations from the 1999 Chi-Chi earthquake.