Construction method of superimposed prefabricated foundation pit structure with reverse frame

Abstract

The invention relates to the field of building underground engineering, in particular to a construction method for a framework top-down overlapped assembly type foundation pit structure. The method comprises the following steps that A, a foundation pit is arranged, piling points of the foundation pit are designed, a socketed pile is driven into each piling point, the pile foundation depth is larger than the depth of a basement, that is, the piles penetrate through a soft clay layer and are driven into a rock layer, and socket end piles are formed; B, an enclosure is arranged, guard plate trenches are dug between the piling points at the edge of the foundation pit, the depth of the guard plate trenches is matched with the depth of the basement to be constructed, and guard plates are installed in the trenches; C, bottom grouting is carried out, specifically, grouting holes are formed in the soil surface, the depth of the grouting holes is matched with the depth of the basement, and then grout is poured into the grouting holes, so that a waterproof layer is formed at the bottom of the basement; and D, top-down excavation is carried out downwards from the soil surface, and construction is carried out layer by layer till construction of the whole basement is completed.

Description

technical field [0001] The invention relates to the field of building underground engineering, in particular to a construction method for a frame-backed stackable assembled foundation pit structure. Background technique [0002] At present, for the construction of the underground structure whose surface layer is soft soil layer and the bottom layer is rock layer, the following steps are often adopted: 1. Pile driving to the rock layer; 2. Cast-in-place underground continuous wall, the depth of the wall also reaches the rock layer; 3. Earth excavation. The advantage of this kind of construction is that end-bearing piles are used to bear the force, and the supporting effect is good. The underground diaphragm wall running through the entire soft soil layer can effectively isolate the flowing water in the soft soil layer from entering the basement. However, this construction method has the following disadvantages: 1. The depth of the continuous wall is large, and the constructi...

AI Technical Summary

Problems solved by technology

However, this construction method has the following disadvantages: 1. The depth of the continuous wall is large and the construction cost is high; 2. The cast-in-place wall has hidden dangers of water leakage, and it is difficult to determine the location of the water leakage

However, when the embedding depth of the water-resisting layer is large, the underground diaphragm wall is embedded in the water-resisting layer soil, and the cost will increase significantly

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