Preformed hole deep-layer underwater tamping method

Abstract

A preformed hole deep-layer underwater tamping method is characterized in underwater construction: foundation soil below the underground water level is consolidated; a tamper rises from and falls in water, and the action point of the tamper and foundation soil is located below the underground water level; the tamper keeps hooked during construction to achieve underwater continuous operation. The preformed hole deep-layer underwater tamping method includes the following steps: (1) preforming a hole in foundation soil; (2) conducting padding in the hole for the first time, wherein the padding amount is controlled by the layered padding thickness; (3) conducting tamping in the hole for the first time, making the tamping energy to be matched with the layered padding thickness, keeping the tamper hooked during tamping, automatically measuring the settlement, and conducting tamping gradually until the tamping stopping standards are met; (4) repeating steps 2 and 3, conducting backfilling and tamping layer by layer from bottom to top, and conducting padding and tamping alternately until the ground elevation is reached and construction of one hole is finished; (5) repeating steps 1-4 to complete construction of all holes; (6) tamping the soil on the surface layer in a full tamping mode. The preformed hole deep-layer underwater tamping method has the advantages of underwater construction, deep-layer consolidation, low production cost, short construction period, high efficiency, energy conservation and environmental protection.

Description

technical field [0001] The invention relates to the technical field of foundation treatment, and relates to a pre-hole deep underwater compaction method and a foundation treatment technology for reinforcing deep underwater foundation soil. Background technique [0002] The ground treatment technology of the dynamic compaction method is to use a large crawler crane to freely drop a heavy hammer of a certain mass from a certain height to compact the soil strongly. It is suitable for treating gravel soil, sandy soil, silt and clayey soil with low saturation, collapsible loess, miscellaneous filling soil and plain filling soil and other foundations. But its treatment depth is limited, generally no more than 15m ~ 20m. [0003] The deep hole dynamic compaction method is to form a hole with a machine tool, and then tamp the filler in the hole, compact it into a pile, and work together with the soil between the piles to form a composite foundation. However, there are problems suc...

AI Technical Summary

Problems solved by technology

However, there are problems such as the need for manual hooks and the difficulty in accurately measuring the amount of tamping, which makes it difficult to realize deep underwater construction operations. At the same time, its treatment effect is mainly on the compaction and punching of the filler in the hole, and it is difficult to achieve real dynamic tamping vibration. The effect of reinforcement

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