Rapid impact compactor for abutment back treatment in Jiangxi, China

There is a lack of permeable filler along Jiangxi expressway. Impermeable filler is used for filling construction at the abutment back of bridge and culvert. Since the vibratory roller cannot effectively compact the subgrade near the abutment back, and the subgrade quality cannot meet the standard, the Rapid impact compactor is selected for construction to make the pavement quality meet the standard. According to the characteristics of Jiangxi expressway, the practical application of Rapid impact compactor is experimentally studied.

First of all, before filling the subgrade, the construction site needs to be sorted out, and the sundries within the scope of the foundation should be cleared, and then the foundation should be leveled and compacted by appropriate mechanical equipment to ensure that the compactness exceeds 85%. Then test the basic bearing capacity of the foundation, and test whether the bearing capacity of each position meets the standard requirement of 200KPa. If it does not meet the standard, it is necessary to continue compaction until the bearing capacity requirements are met.

Secondly, select qualified fillers to ensure that the fillers used in the test are the same as those used in the field construction, so as to control the test results and ensure their accuracy. Third, it is necessary to strictly control the length of the filler at the back of the abutment, which should be at least three to four times the abutment height to meet the test requirements. Fourth, in the process of filling construction, using a roller with a specification of more than 20t, layered filling should be carried out within the radius of more than 1m centered on the abutment. During the construction process, attention should be paid to avoid the compaction thickness of more than 20cm, because the thickness of the Rapid impact compactor is not conducive to the compaction thickness.

Finally, after the filling basically meets the test requirements, the tamping machine can be used for reinforcement, and the corresponding tests can be carried out during the operation.

Because the Rapid impact compactor has too much tamping power, the construction personnel need to determine its safe construction distance in advance to ensure the construction safety near the subgrade, bridge and culvert and the road will not be affected. The safe construction distance refers to the length from the midpoint of compaction construction to the abutment back. According to the existing back compaction test results, the safety distance is 70cm. The radius of the compaction hammer of the Rapid impact compactor reaches 60cm, that is, the minimum length between the compaction hammer and the abutment back is 10cm. The compaction hammer point is set as plum blossom pile, the distance between hammer centers is 200cm, and the edge distance of each construction point is 100cm.