Construction method of quick refreezing and backfilling of foundation soil of tower foundation in permafrost region

Abstract

The invention discloses a quick re-freezing and backfilling construction method for foundation ground of a tower foundation in a frozen ground area. The method comprises the following steps of backfilling first frozen ground at the base of a foundation pit in a layering way, i.e. tamping the backfilled first frozen ground layer after the first frozen ground is backfilled into the foundation pit each time, detecting the ground density of the tamped and backfilled first frozen ground layer until the detection value is greater than the preset ground density, and backfilling the next layer of first frozen ground to the foundation pit, wherein the first frozen ground is particulate or blocky undisturbed frozen ground of which the particle size is smaller than or equal to the preset particle size when the foundation pit is dug; when the top surface of the tamped first frozen ground in the foundation pit is within the preset height range in the foundation pit, backfilling second frozen ground into the foundation pit until the top surface of the backfilled second frozen ground is higher than the ground surface preset height of the frozen ground area, wherein the second frozen ground is blocky undisturbed frozen ground of which the particle size is greater than the preset particle size when the foundation pit is dug; and carrying out still treatment on the tower foundation. The method is used for realizing quick re-freezing and backfilling of the foundation ground of the tower foundation in the frozen ground area.

Description

technical field [0001] The invention relates to the engineering technology of tower foundations of power transmission lines, in particular to a construction method for rapid freezing and backfilling of foundation soil of tower foundations in permafrost regions. Background technique [0002] Frozen ground is soil and / or rock containing ice with a temperature below 0°C and is very sensitive to temperature. In nature, according to the length of existence time, it is divided into seasonal frozen soil and permafrost. Permafrost regions generally refer to permafrost regions, which are mainly distributed in the Qinghai-Tibet Plateau, the western alpine regions, and the Greater and Lesser Khingan Mountains in the northeast of my country. Because permafrost is very sensitive to temperature, whether the foundation in permafrost areas is frozen or not directly affects the ability of the foundation to prevent water infiltration and the bearing capacity of the foundation. [0003] Exca...

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Problems solved by technology

[0004] The defects in the above-mentioned prior art mainly include: the static period of the tower foundation is long, resulting in a long construction period, which increases the consumption of manpower, material resources, and financial resources; The soil compactness of the backfill cannot meet the design requirements, and the practice shows that this construction method has poor ground thawing effect and maintaining a frozen state, which has a great impact on the construction quality of the transmission tower foundation.

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