Construction technology and construction method for large-particle-size pebble stratum super-deep foundation pit in strong water permeation environment of Yellow River flood plain

Abstract

The invention discloses a construction technology and construction method for a large-particle-size pebble stratum super-deep foundation pit in the strong water permeation environment of a Yellow River flood plain. The construction technology comprises enclosing structure construction, dewatering construction and main body structure construction and is characterized in that the enclosing structure construction consists of a 1.2m-thickness reinforced concrete underground continuous wall and a 0.8m-thickness plain concrete water stopping wall, a lining wall of a foundation pit wall and the continuous wall adopt a superimposed wall structural form, end reinforcing sleeve valve pipes are grouted, and a main body structure adopts fully enclosed water-proof design; the dewatering construction adopts a treating means combining a continuous wall water stopping curtain and foundation pit bottom sealing in-pit dewatering; and the main body structure construction is carried out in a way that the main body is of a five-layer cast-in-place reinforced concrete box type framework structure, 34 lattice columns are arranged in the foundation pit to support the weight of the main body structure, construction is carried out by an open excavation reverse construction means, and excavation construction is carried out for six times. The technology and the method overcome the defects of the traditional construction of the large-particle-size pebble stratum super-deep foundation pit in the strong water permeation environment of the Yellow River flood plain and can provide a great reference for further similar engineering.

Description

technical field [0001] The invention relates to an ultra-deep foundation pit construction technology, in particular to an ultra-deep foundation pit construction technology in a large-diameter pebble layer under the Yellow River floodplain environment with strong water permeability. Background technique [0002] With the development of urban construction, the scale and construction difficulty of subway deep foundation pit construction projects are also increasing. How to reduce the impact on the surrounding environment due to the excavation and precipitation of the deep foundation pit of the subway has become a key issue that people pay more and more attention to. At present, the existing construction technology is relatively mature in the soft soil area, but there is no construction case for the large-size pebble layer under the strong permeable environment of the Yellow River floodplain. The research on foundation pit construction technology is very necessary, and has impo...

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Problems solved by technology

[0003] At present, most of the enclosure structures of ultra-deep foundation pits adopt single-layer continuous walls, bored piles, jet grouting piles, etc. After analysis and research, the commonly used single-layer enclosure structures are used in ultra-deep foundation pits with large-size pebble layers in strong water-permeable environments It often does not play a good role in enclosure and waterproofing, and water leakage often occurs in foundation pits, which brings many difficulties and risks to engineering construction. Under this environment, the reverse construction of ultra-deep foundation pits is still rare in China. It is the first case, so it is of great significance to study the construction technology of ultra-deep foundation pit in the large-size pebble layer under the strong permeable environment of the Yellow River floodplain, which can provide a good reference for similar projects in the future

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