Middle plate construction method of wide pit top-down construction

Abstract

The invention relates to underground construction, in particular to a construction method for a median plate under the condition of construction of a wide foundation pit by the reverse construction method. The method comprises the following steps: an earthwork in the middle is excavated first, and tables are preserved near an enclosing structure to control deformation of the enclosing structure; when concrete slabs are subjected to placing, a reinforced concrete slab in the middle is constructed first and tables on both sides are excavated after subdividing when the reinforced concrete slab in the middle reaches the strength; and concrete slabs on both sides near the enclosing structure are symmetrically constructed after subdividing. The construction method has reasonable excavating and placing sequence, is favorable for controlling deformation of the foundation pit, saves the construction period, and is convenient to construct.

Description

technical field [0001] The invention relates to underground engineering constructions, in particular to a mid-slab construction method for large foundation pits constructed by the reverse construction method. Background technique [0002] The construction of the foundation pit using the reverse method can advance the construction time of the superstructure and save the total construction period. Since the supporting effect of each floor slab is better than that of steel support or reinforced concrete support system, the reverse construction method is more beneficial to the stability of the foundation pit. Therefore, reverse construction is widely used in the construction of underground engineering. [0003] In the past, when constructing the middle slab by the upside-down method, the formwork mostly used the soil formwork or the bracket method alone. In soil formwork construction, in order to ensure the pouring quality of the slabs, wooden formwork is still used. Because ...

AI Technical Summary

Problems solved by technology

Because it is not easy to dismantle, the loss of formwork is large, and the cushion layer is easy to attach to the bottom of the middle plate when excavating the next layer, causing great safety hazards; when using brackets, shorter wooden brackets are often used, which is not conducive to Dismantling, and the loss during construction is relatively large

In addition, there are also projects that use slightly longer steel pipe supports. This kind of support is convenient for the removal of the formwork, which is beneficial to the construction progress and can save costs, but it is easy to cause over-excavation of the foundation pit, which is not good for controlling the deformation of the enclosure structure.

[0004] In addition, during the construction of the middle slab, the middle slab is often divided into blocks according to the convenience of construction. The size and order of the blocks are relatively random, which is sometimes very unfavorable for controlling the deformation of the foundation pit

Therefore, at present, the excavation and division of large foundation pits have not yet formed a unified scientific order. During the construction of various projects, it is not conducive to the safety of foundation pit engineering.

Images