Abstract: Based on the improvement practice on the reclaimed land on the site of express mail disposal center of Pudong International Airport, the construction technology of improving hydraulic silty fine sand and saturated soft clay on the reclaimed land with DDCM (dynamic and drain consolidation method) is presented. Combined with testing of properties of soils before and after improving, the field test results on the testing area for dynamic consolidation on the hydraulic silty fine sand show that it is feasible to improve the saturated soft clay on the reclaimed land with the new construction technology of low-energy and “fewer times and more cycles” dynamic compaction combined with the plastic vertical drain. The mechanical property and deformation characteristics of saturated soft clay on reclaimed land are improved obviously after improving with the new technology above mentioned. It has been achieved to use hydraulic filled silty fine sand as the dynamic consolidation cushion in this project. The investment has also been reduced largely with the use of hydraulic filled silty fine sand instead of mid-coarse sand as the cushion for dynamic consolidation. The test results of the improving construction on the large area of reclaimed land show further that the improvement effect of DDCM on reclaimed land is remark.

Key words: reclaimed land, plastic vertical drain, dynamic consolidation technology, saturated soft clay, hydraulic filled silty fine sand, soil improvement