Construction method for flexible composite impermeable layer of upstream face of high arch dam

Abstract

Disclosed is a construction method for a flexible composite impermeable layer of an upstream face of a high arch dam. The inner layer of the composite impermeable layer serves as an inner protective layer coated with GB plastic sealant or bonded with GB plastic sealing plates; the outer layer of the composite impermeable layer serves as an outer protective layer of the composite impermeable layer of the upstream face of the high arch dam and is formed by spraying spray polyurea elastomers on the GB plastic sealing plates, and covers the inner protective layer integrally. To prevent local come-off and bulge of the composite impermeable layer with the inner protective layer bonded with the plastic sealing plates and the outer protective layer sprayed with the spray polyurea elastomers, the composite impermeable layer is partitioned by directly spraying the spray polyurea elastomers with the width of 30cm in each section of the dam horizontally at the height of 5m. The flexible composite impermeable layer is impermeable even when 8mm cracks of concrete of the high arch dam are produced under action of waterhead, and accordingly, integral impermeability, crack resistance and durability of the upstream face of the high arch dam can be improved, hydraulic fracture caused by cracking of the upstream face of the dam is reduced, and safety of the dam is improved further.

Description

technical field [0001] The invention relates to a construction method for a flexible anti-seepage structure on the upstream face of a high arch dam, in particular to a construction method for a composite anti-seepage layer on the upstream face of a high arch dam composed of high-strength flexible materials and plastic sealing plates. Background technique [0002] Domestic and foreign engineering practice, calculation analysis, and model tests show that the heel of high arch dams belongs to the strong constraint area during the construction period, and the stress during the operation period is complex, and cracks are likely to appear in the foundation; excessive pressure in the upstream surface tensile stress area will also It leads to concrete cracks, and the concrete cracks will undergo hydraulic splitting under the action of high water head water pressure, and the cracks will further expand, resulting in cracking of the anti-seepage curtain, leakage of the concrete dam body...

AI Technical Summary

Problems solved by technology

[0002] Domestic and foreign engineering practice, calculation analysis, and model tests show that the heel of high arch dams belongs to the strong constraint area during the construction period, and the stress during the operation period is complex, and cracks are likely to appear in the foundation; excessive pressure in the upstream surface tensile stress area will also It leads to concrete cracks, and the concrete cracks will undergo hydraulic splitting under the action of high water head water pressure, and the cracks will further expand, resulting in cracking of the anti-seepage curtain, leakage of the concrete dam body and dam foundation, seriously damaging the integrity of the dam concrete, and greatly affecting The dam works normally, even endangering the safety of the dam

During the operation period, because there is no condition to empty the reservoir, under the action of high pressure water head, once cracks appear in the dam body, it is difficult to repair the cracks at deep water level

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