What are tie reinforcement and skirt reinforcement?

"Stripping reinforcement" and "skirt reinforcement" refer to the horizontal arrangement of foundation pit reinforcement measures. Stripping reinforcement means that the reinforcement measures are arranged in a grate shape (one by one) on the whole foundation pit plane, and skirt reinforcement means that the reinforcement measures are only arranged around the foundation pit, similar to wide skirts.

Deformation of foundation pit. In the process of foundation pit excavation, the retaining structure is displaced under the action of internal and external pressure difference due to excavation unloading, which further causes the deformation of soil outside the retaining structure and the settlement and movement of soil or buildings outside the foundation pit.

Extended data:

For the local or overall deviation of building structures and engineering structures caused by various reasons (such as foundation settlement, foundation construction, etc.), stress relief method, pile cutting method and jacking method are adopted, and information feedback method is used to correct the deviation.

Structural underpinning technology refers to the functional transformation of the original load-bearing structure that affects the use function of the building by changing the stress system, in order to obtain a more ideal use space. Structural underpinning methods generally include steel underpinning, reinforced concrete underpinning and truss underpinning.

Foundation underpinning technology refers to the subway or underground tunnel built in the city inevitably passing under the building. In order to avoid demolition and reconstruction, pile foundation underpinning must be carried out for ground buildings.

This technology mainly uses the beam transfer floor near the pile cap to transfer the upper load borne by this pile foundation to the new pile foundation outside the tunnel and replace it with the underpinning structure system composed of underpinning beam and new pile.

At the same time, in order to ensure that the underpinning buildings will not be damaged due to cracking and inclination after the broken piles and tunnels pass through, technologies such as prestressed tensioning of underpinning beams, jack-up and grouting at the bottom of piles are adopted, and many patented technologies such as miniature rock-socketed steel pipe cast-in-place piles and concrete interface connection technology can be applied to pile foundation underpinning.

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