Construction effect of backfill soil compaction for building foundation with rapid impact compactor

1) Before filling the roadbed with the rapid impact compactor, remove the surface soil and tree roots within the basement range, level and compact the basement, and the compaction degree is not less than 90%. At the same time, to test the basic bearing capacity of the substrate, it is necessary to strengthen the position where the bearing capacity of the substrate is lower than 150kPa. 2) The field filler is the same as the filler selected in the test. 3) For the backfilling range of the abutment, the length of the backfilling of the bridge abutment shall not be less than 3 to 4 times the height of the platform. 4) Use a rapid impact compaction machine to fill 18t or more of road rollers in layers around the bridge abutment. The thickness of each layer is not more than 25cm, and the vibration is rolled (not less than 8 times). The static pressure is within 1m (not less than 8 times). 5) After compacting different subgrade heights, use a compactor to reinforce, and conduct relevant tests during the compaction process of a rapid impact compaction equipment. The safe construction distance is the distance from the midpoint of the compaction operation to the back of the table. The existing table back compaction test results show that the compaction radius of the compactor is 60cm, and the compaction radius of the compactor is 50cm, that is, the minimum distance between the compactor and the table back is 10cm. The hammer-type distribution point adopts plum blossom pile type, the distance between the hammer center and the hammer center is 150cm, and the margin between the two operation points is 50cm. 6) After the hydraulic compactor is compacted, relevant inspections are carried out. The bearing capacity of the road base after tamping should reach more than 180kPa.

1) From the vertical stress, basic bearing capacity, settlement and compaction degree of the test subgrade along the depth direction, it can be seen that the impact depth of the compactor on the subgrade at the construction site is 2.5m, and it is recommended that the subgrade compaction height be less than 2.5 m. m. 2) It is recommended that the subgrade compaction process on the back of the platform adopts 12 hammers or 9 hammers in the 3rd gear. The distance between the two hammer centers of the plum blossom pile is 1.5m, and the minimum distance between the compaction hammer of the hydraulic tamper and the platform back is 0.1m. 3) It is recommended to use a light dynamic detector to detect the compaction effect. After the hydraulic compactor compacts the roadbed, the average value of the basic bearing capacity should be increased by 20kpa. After compacting the subgrade, the basic bearing capacity should reach 180kpa. 4) For the silt used in the test site, although the compaction performance meets the requirements, in order to ensure water stability, it is recommended that the hydraulic compactor compact and fill the subgrade behind the test site to the design elevation of 120cm, and then fill with 20cm thick gravel. (Natural gradation, the maximum particle size is not more than 5cm).

Rapid impact compactor can solve the problem of lack of water-permeable backfill and water source in mountain highway construction. Using the advantages of the action mechanism of the rapid impact compaction machine, making full use of the soil sources that meet the requirements along the line, speeding up the construction progress, shortening the construction period, and saving nearly 60% of the cost (compared with the watertight method of backfilling medium-coarse sand and filling compaction), it has obvious advantages. social benefit.