Shaking Table Tests and Analyses on the Evaluation of Appropriate Densification Area Against Soil Liqufaction

Abstract eng:
Among the countermeasures against liquefaction, densification methods by sand compaction piles, stone columns et al., have been widely used because of their high reliability. In the design of densification methods, it is necessary to decide the area to be improved. In 1978, a method to decide the area was introduced in the code for oil tanks in Japan. After that, several methods were proposed. However, the areas for improvement estimated by the proposed methods are quite different. Moreover, the definition of damaged and undamaged structures is not clear. More rational methods to evaluate liquefaction-induced damage to structures should be developed. An appropriate way must be to introduce performance-based design based on allowable settlement of structures. Then the authors conducted shaking table tests and analyses under several conditions on different areas and densities for improvement. Two models were selected for the tests and analyses. The first model was an old LP gas tank which settled about 64 cm on average and the second model was an apartment house which settled about 10 cm during the 1995 Kobe earthquake. Both structures were settled due to liquefaction though some area of foundation grounds had been improved by densification methods. Shaking table tests were carried out under several conditions of soil compaction area. Test results showed settlements decreased with the increase of the compaction area. An analytical code “ALID” was used to estimate the settlement of the tank and the house. Analyzed settlements of the tank and the house were similar as the settlements obtained by shaking table tests.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket