Piled raft foundation anti-floating structure and construction method

Abstract

The invention relates to a piled raft foundation anti-floating structure and a construction method. A basement side wall is connected with a supporting pile through transverse connecting reinforcing steel bars, cast-in-situ bored piles are arranged below a basement base plate in a drilled mode, and a broken stone hardcore, a backfill lime earth layer, a reinforced concrete water-stop sheet, a soft soil layer and a relative supporting layer are sequentially arranged at the lower portion of the basement base plate from top to bottom; the reinforced concrete water-stop sheet is located close to the bottom end of a waterproof curtain, and closed waterproof space is formed between the reinforced concrete water-stop sheet and the waterproof curtain; the reinforced concrete water-stop sheet is connected with the supporting pile through connecting reinforcing steel bars, holes are formed in the reinforced concrete water-stop sheet at intervals, and anti-floating anchor rods are inserted into the relative supporting layer in a penetrating mode through the holes. The piled raft foundation anti-floating structure has the advantages that the good bearing performance and the good anti-floating performance are achieved, damage to the portion where a raft is connected with a piled raft is small, the base plate is not prone to leakage, the construction speed is high, and the manufacturing cost is low; the good technical economy benefits are achieved.

Description

technical field [0001] The invention relates to an anti-floating structure and a construction method of a pile raft foundation, which has fast construction, low cost and anti-floating ability, and belongs to the field of construction engineering. Background technique [0002] For the purpose of expanding the use of functions and developing underground space, high-rise buildings are generally designed with basements with larger plan dimensions and depths. However, in the coastal cities where the underground soil is rich in water, the buoyancy of the groundwater causes the superstructures such as buildings and structures to tilt and collapse frequently, which makes the problem of anti-floating of the basement increasingly prominent. [0003] Pile-raft foundation is an organic combination of pile foundation and raft foundation, and has the characteristics of both pile foundation and raft foundation: large overall rigidity, high bearing capacity, strong deformation resistance, a...

AI Technical Summary

Problems solved by technology

[0004] There are three commonly used anti-floating measures for existing large-scale piled raft structures: one is ballast anti-floating technology, that is, adding counterweight to the basement floor or increasing the thickness of the floor to offset the buoyancy of groundwater on the raft, increasing the thickness of the floor The anti-floating of underground structures is very effective, but the buried depth of the foundation will inevitably increase, and the buoyancy of groundwater will also increase accordingly. Therefore, the anti-floating design is more difficult, and the construction effect is difficult to meet the design requirements; Its own tensile strength pulls the basement structure as a whole and the rock layer or hard soil layer. Under the raft foundation, uplift anchors are usually arranged all over the house, so the use of uplift anchors is large, which is easy to cause waste of building materials; because of long-term contact with groundwater , so the anti-corrosion requirements of the anti-uplift anchor are very high, and the anti-uplift anchor cannot bear the downward load; the third is the anti-floating pile technology, the anti-floating pile uses the pile body's own weight and pile side friction to provide anti-buoyancy, because the pile Connected with the columns, the distance between the anti-floating piles is too large, and a thick bottom plate is required to resist the additional bending moment and shear force generated by buoyancy, so the cost of the bottom plate is also high except for the high cost of the piles

[0005] To sum up, although the existing pile-raft foundation anti-floating structure has achieved remarkable results in anti-floating performance and anti-seepage performance, and has reduced the damage caused by the continuous change of groundwater level to the basement side wall and floor, there are still some problems. The areas that can be improved are mainly reflected in the relatively high construction difficulty and high construction cost.

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