1, survey lofting: use 1 DS-3 level and 1 J6 theodolite to determine the dynamic compaction area and point layout according to the construction drawing requirements, and arrange coordinate control point piles outside the dynamic compaction range, and reasonably arrange leveling points around them as the basis for controlling elevation and subgrade settlement.
2. Trial tamping: Before dynamic tamping construction, trial tamping shall be conducted to determine the weight, bottom area and falling distance of the rammer, so as to determine the final settlement, the corresponding minimum tamping times and the total settlement. 3. Key points of construction:
1) Cushion laying: After the bulldozer site is leveled, a gravel cushion with a thickness of 0.5~2m shall be laid to facilitate the drainage of the site during compaction, facilitate the passage of machinery and enable the compaction to unfold.
2) Dynamic compaction construction: After the tamping point is located, equipment for pressure measurement (tamping stress, pore water pressure), vibration measurement (frequency, amplitude, wave velocity) and deformation measurement (in soil and underground) can be buried in the predetermined observation section, and tamping can be carried out in batches and times according to the design requirements.
When tamping, we should measure and record the energy of each tamping point, the tamping times, the subsidence of each tamping pit, the uplift of the soil around the tamping pit and the buried measuring points, and pay attention to the influence range and degree of tamping vibration. After the point tamping is completed, it shall be fully rammed according to the design requirements.