A construction method of anti-floating pile raft structure combined with deep rotary grouting cement-soil slab and anchor rod

Abstract

The invention discloses an anti-floating piled raft structure combining a deep-layer jet-grouting cement-soil board and an anchor and a construction method. A continuous large-thickness deep-layer cement soil board which is formed in a high-pressure jet grouting mode is arranged at the design position in a foundation, a large-diameter jet grouting pile and a small-diameter jet grouting pile are further arranged on the cement soil board, a compound pile of prestressed pipe piles is inserted into the large-diameter jet grouting pile to serve as a vertical bearing pile, the top of the prestressed pipe piles is sealed and provided with an anti-floating screw and an anti-floating end plate, the anti-floating screw and the anti-floating end plate are connected with a raft foundation, the anti-floating anchor is implanted into the small-diameter jet grouting pile, and a rear expansion end plate is arranged at the bottom of the anti-floating anchor, and is arranged at the bottom of the deep-layer cement soil board. The anti-floating piled raft structure combining the deep-layer jet-grouting cement-soil board and the anchor and the construction method have the advantages that the capacity of surrounding soil is fully utilized for resisting buoyancy, a reliable anchoring point is provided for the anchor, the anchor distance can be effectively shortened, and the cost is reduced. Combination of the prestressed pipe piles, the large-diameter high-pressure jet grouting pile, the small-diameter high-pressure jet grouting pile and the short anti-floating anchor is adopted for the foundation, and the good vertical bearing capacity, the high buoyancy resistance performance and the like are achieved.

Description

technical field [0001] The invention relates to a pile raft structure and a construction method, more specifically, it relates to an anti-floating pile raft structure and a construction method of a combination of deep rotary sprayed cement-soil slabs and anchor rods, and belongs to the field of foundation treatment. Background technique [0002] With the rapid development of urban construction, a large number of high-rise buildings, underground garages, sunken squares, subways, underground shopping malls and other buildings have put forward higher requirements for the utilization of underground space. However, in coastal cities such as Shenzhen, Dalian, and Qingdao, where the underground soil is rich in water and the nature of the soil is soft soil with a large thickness, accidents of tilting and collapse of buildings and structures caused by the buoyancy of groundwater occur frequently. , making the basement anti-floating problem increasingly prominent. [0003] Pile-raft ...

AI Technical Summary

Problems solved by technology

[0005] Although the traditional anti-floating anchor has the above advantages, it also has its shortcomings and shortcomings: firstly, the longer the anchor, the better the anchoring effect of the anchor, but in deep soft soil areas, in order to obtain a good anchoring effect , the length of the anchor is bound to increase, which obviously increases the difficulty and cost of construction; secondly, a longer anchor will inevitably increase the difficulty and quality of grouting, which will affect the anchoring effect; Buried anchors will cause problems such as hole collapse, especially for areas with deep soft soil layers, which will affect the anchoring effect of anchors; finally, the contribution of anchors to the vertical bearing capacity of the foundation is very limited, and generally other structures need to be set up to bear vertical bearing capacity

However, the setting of barbs increases the processing difficulty of the anchor rod and increases the production cost. At the same time, the barbs may cause outward radial force, which may cause the grouting body to crack and affect the anchoring effect, and may cause the anchor rod to corrode.

Moreover, the same setting of this type of anchor still needs to be additionally provided with pile foundations that can provide the bearing performance of the foundation.

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