Consolidation grouting combined with double-row steel pipe pile support method for ultra-deep foundation pit with miscellaneous fill

Abstract

The invention discloses a supporting construction method for a miscellaneous fill ultra-deep foundation pit through combination of consolidation grouting and double-row steel pipe piles. The supporting construction method comprises the following steps that firstly, the steel pipe piles and a grouting soil-retaining structure are constructed; and secondly, rear impact self-advancing anchor rods areconstructed. According to the construction method, the problem that supporting piles and walls of an adjacent building cannot be constructed under the situation of the ultra-deep foundation pit withmiscellaneous fill in the upper portion and rock in the lower portion is solved. By utilizing a combined supporting technology, disturbance to the foundation pit is greatly reduced, and the safety ofthe existing building is effectively protected; and the double-row steel pipe piles are adopted to be combined with the pressure grouting technology and the perforated pipe grouting technology, the soil-retaining structure with the large thickness and good stiffness is formed and replaces a traditional row pile and continuous wall soil-retaining structure, and the technique is simple relatively.

Description

technical field [0001] The invention relates to a construction method of super-deep foundation pit consolidation grouting combined with double-row steel pipe piles, which belongs to the technical field of building construction. Background technique [0002] With the increasing density of urban buildings, the difficulty of supporting deep foundation pits under various complex geological conditions is gradually increasing. In engineering, loose backfill soil layers with thicker and high loose coefficients are often encountered, and excavation is likely to cause edge The slope is unstable and has a great impact on adjacent buildings. The support structures of adjacent buildings are generally supported by row piles and diaphragm walls to ensure the safety of adjacent structures. If the upper part is filled with soil and the lower part is hard rock, it is also difficult to construct row piles and diaphragm walls. [0003] For the anchor bolt construction of the filled soil layer...

AI Technical Summary

Problems solved by technology

[0003] For the anchor bolt construction of the filled soil layer, casing drilling or self-advancing anchor bolts are often used. For the miscellaneous fill soil containing obstacles such as block stones and concrete blocks, due to the complex composition, many obstacles, large void ratio, water erosion, etc. Drilling with casing is easy to cause ground subsidence, and the drilling efficiency of pneumatic follower casing is low, and the average cost is high, while conventional self-advancing bolts are difficult to drill.

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