Dynamic compaction method for backfill foundation with drainage layer

Abstract

The invention relates to a method for reinforcement treatment of for deep and thick backfill foundation in civil and architectural engineering, in particular to a dynamic compaction method for backfill foundation with a drainage layer. The dynamic compaction method comprises the following construction steps: (1) laying a gravel drainage layer at the bottom of a backfill pit; (2) arranging a dewatering header pipe, and using a water pump to pump percolating water accumulated in the gravel drainage layer at any time; and (3) connecting the dewatering header pipe upwards, carrying out backfill on the gravel drainage layer and then carrying out dynamic compaction. By laying the gravel drainage layer at the bottom of the pit and arranging a collector well and draining water from the backfill foundation rich in terrain cranny water, the dynamic compaction method can effectively reduce the underground water level of the backfill pit and drain the terrain cranny water from the backfill pit intime so as to prevent the underground water from rising to submerge backfill earth; the method can also cause gap water generated in the process of dynamic compaction to be drained quickly and cause excess hydrostatic pressure to disappear quickly to ensure compaction quality; besides, the interval time between multiple times of compaction is also shortened, which benefits for continuous operation and shortening of construction period.

Description

Technical field: [0001] The invention relates to a reinforcement treatment method for deep backfilling foundations in civil construction engineering, and is particularly suitable for backfilling engineering construction of foundations with abundant groundwater. Background technique: [0002] At present, the dynamic compaction method is generally used for reinforcement of deep foundations. Although the treatment depth of the dynamic compaction method is large, the drainage and consolidation of the soil takes a long time. If there is abundant groundwater or other supply water, the interval required for dynamic compaction If the time is long, this will seriously affect the construction period and construction quality; in addition, due to the impact of the tamping energy during the dynamic tamping construction, the backfill with a high moisture content will often cause too much uplift of the soil around the rammed pit and the formation of rubber soil , so that most of the tampin...

AI Technical Summary

Problems solved by technology

[0002] At present, the dynamic compaction method is generally used for reinforcement of deep foundations. Although the treatment depth of the dynamic compaction method is large, the drainage and consolidation of the soil takes a long time. If there is abundant groundwater or other supply water, the interval required for dynamic compaction If the time is long, this will seriously affect the construction period and construction quality; in addition, due to the impact of the tamping energy during the dynamic tamping construction, the backfill with a high moisture content will often cause too much uplift of the soil around the rammed pit and the formation of rubber soil , causing most of the tamping energy to be consumed in the topsoil without being transmitted downwards, thus failing to achieve the expected reinforcement effect

[0003] The most suitable treatment depth of the traditional foundation reinforcement treatment method is generally not more than 15m. If the depth exceeds 15m, it is difficult to ensure the quality of backfill foundation compaction; the existing foundation drainage consolidation method requires high costs for the layout and maintenance of drainage pipes and water collection wells. The dynamic compaction method usually adopts a high-level filling dynamic compaction construction, and mostly uses low compaction energy, which has high compressibility and large post-construction settlement; the existing dynamic compaction method generally only sets vertical drainage wells, and pumps water through high-pressure pump pipes. Row, high cost, long construction period is difficult to meet the construction of areas with high groundwater level and abundant water

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