Abstract: Based on the field test of vacuum combined with surcharge preloading reinforced soft ground in highway test section, the centrifugal model is built to perform the centrifugal test on vacuum combined with surcharge preloading reinforced lacustrine soft soil. The settlement law of soft ground under the effect of vacuum combined with surcharge preloading is analyzed. The test settlement is compared with the measured settlement in order to study the settlement relationship between them. By the above analysis and comparison, the results show that the settlement of soft ground during construction is more than 87% of total settlement under the effect of vacuum combined with surcharge preloading, which is effective to reinforce lacustrine soft soil. Using the vacuum combined with surcharge preloading to reinforce soft ground, the settlement development of soft ground after construction is slow; the settlement value of soft ground after construction is no more than 2.5 cm in two years; and the settlement difference of embankment section is less than 5 mm. It is clear that the settlement of soft ground after construction will not affect the normal operation of highway. The settlement trends of centrifugal test and field test are basically similar; but the settlement values of them have differences due to the impacts of the condition of field test and the errors of centrifugal test.

Key words: vacuum combined with surcharge preloading, lacustrine soft soil, soft ground, centrifugal test, consolidation settlement