Abstract:With the construction of island reclamation projects in “the Belt and Road” , the problem of coral reef sand foundation treatment has attracted more and more attention from the engineering community.As an effective treatment method for sandy condition, stone columns mainly include two construction techniques：vibro-replacement stone column and vibrating tube stone column.Relying on the ground improvement project in the Red Sea of Saudi Arabia, a typical test area of vibro-replacement stone column and vibrating tube stone column is carried out, and the principle of soil reinforcement by stone column is explained.Starting from cone penetration test（CPT）, plate load test（PLT） and zone load test（ZLT）detection and analysis, settlement calculation is carried out using Settle 3 software, and the construction technology, construction efficiency and reinforcement effect of the two are compared.The results show that both 10% and 12.5% replacement rates can meet the design requirements of bearing capacity, settlement and anti-liquefaction;under the same replacement rate conditions, the vibrating tube stone column has a better effect on soil reinforcement than vibro-replacement stone column, but its work efficiency is lower than that of the vibro-replacement stone column.The test results can provide some reference for the selection of foundation treatment methods for similar coral reef sand.
