Replacing method of bottom plate of foundation pit in muddy soil layer in deep foundation pit support construction

Abstract

The invention discloses a support replacing method for a bottom plate of a mucky soil layer foundation pit in deep foundation pit supporting construction. The method comprises the following steps that S1, construction of a foundation pit surrounding structure and a horizontal support in the foundation pit is completed; S2, a brick moulding bed is built on the outer side of the circumference of a basement bottom plate; S3, a supporting plate strip is mounted between the outer side of the brick moulding bed and the foundation pit surrounding structure; a force transmission device is arranged in a post-cast strip of the bottom plate; S5, after a whole horizontal supporting structure is formed by the basement bottom plate and the supporting plate strip, the horizontal support, above the bottom plate, inside the foundation pit can be dismounted, and support replacing is completed. The supporting plate strip is arranged between the outer side of the brick moulding bed of the bottom plate and the foundation pit surrounding structure, rigidity characteristics of the foundation pit surrounding structure are combined, joist steel is adopted in the supporting plate strip to carry out targeted local reinforcing on surrounding piles, and the foundation pit surrounding structure and the brick moulding bed are matched to form the supporting plate strip with different degrees of stiffness. The power transmission device is arranged in the post-cast strip, the bottom plate can be effectively connected into a whole, and the bottom plate horizontal supporting structure is formed.

Description

technical field [0001] The invention belongs to the technical field of building construction, and in particular relates to a support replacement method for foundation pit bottom plates in muddy soil layers during deep foundation pit support construction. Background technique [0002] At present, in the process of deep foundation pit support construction, steel or concrete support piles and enclosures are usually used as the enclosure structure, and steel or concrete horizontal supports are set at the enclosure position in the foundation pit to form an overall support system. When changing bracing, set up a bracing belt between the basement floor or floor and the foundation pit enclosure structure, and replace the horizontal support in the pit together with the basement floor or floor structure. Usually, the braces are uniformly reinforced, but the stiffness and shear bearing capacity of the surrounding piles in the foundation pit support enclosure structure are much larger t...

AI Technical Summary

Problems solved by technology

Usually, the braces are uniformly reinforced, but the stiffness and shear bearing capacity of the surrounding piles in the foundation pit support enclosure structure are much larger than the water-stop enclosures arranged between the enclosures, which easily leads to the replacement of the braces. Due to the excessive load transfer to the water-stop enclosure structure, the water-stop enclosure structure is damaged, which threatens the safety of the foundation pit

Moreover, most bottom plates are equipped with post-casting belts, and the current support replacement scheme cannot normally carry out the support of the foundation floor under the working condition of the bottom plate with post-casting belts due to its limited ability to resist horizontal loads

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