INFLUENCE OF BUILDINGS ON POTENTIAL LIQUEFACTION DAMAGE

The potential for liquefaction below a building is often evaluated by treating the soil as if it were in the free field. A summary of available field case histories, shaking table model tests, and centrifuge model tests is presented; this clearly indicates that the excess pore pressure distribution near a building can be much different than in the free field. Modifications to the typical free-field liquefaction analysis procedure to account for changes in the vertical stress, horizontal shear stresses, and overconsolidation ratio due to a structure are suggested. Soil-structure interaction effects on the potential for liquefaction are also examined. Comparisions with free-field conditions suggest that the potential for liquefaction damage may be greater or lesser beneath a building depending on the building type and soil density. Sands below short-period, low-rise structures appear to have higher potential for liquefaction than predicted by simplified methods while sands below tall, long-period structures appear to have lower liquefaction potential than sands in the free field. © ASCE.