COMPARISON OF DOWN-HOLE DYNAMIC COMPACTION AND VIBRATING SINKING-TUBE GRAVEL PILE WHICH ARE APPLIED IN AIRPORT GROUND TREATMENT IN SOUTHWESTERN MOUNTAIN AREA

Down-hole dynamic compaction(abbreviated as DDC pile) is a ground treatment method that the filling is dynamically compacted from the bottom upby several times in the hole bored to the desired depth, in order to form the high bearing capacity dense pile and make soil strongly compacted. When the filling is gravel, DDC pile is not only an effective method of compacting and replacing soil but provide a verticaldrain path to consolidate soil more quickly. Vibrating sinking-tube gravel pile is a widely applied ground treatment method. There is a great difference between the two methods, but mechanical principle and improving soil principle are similar when dealing with cohesive soil. DDC pile can be viewed as large diameter vibrating sinking-tube gravel pile, which is arranged sparsely. Meanwhile, vibrating sinking-tube gravel pile can be viewed as small diameter DDC pile, which is arranged densely. Based on the ground treatment of airport in southwestern mountainous area, the theoretical derivation or quantitative analysis of the four aspects of consolidation effect, shear strength index, cost and efficiency and quality control are analyzed and compared in this paper. It is hoped that the theoretical basis and engineering experience in this paper will help geotechnical engineers in the choice of methods in airport ground treatment in mountainous area.