Ultra-flat cavern middle rock pillar supporting structure and construction method

Abstract

The invention discloses a construction method of an ultra-flat cavern middle rock pillar supporting structure. The construction method of the ultra-flat cavern middle rock pillar supporting structurecomprises the following steps that partitioning the cross section of a cavern is carried out, the cross section of the cavern is partitioned into a middle pilot tunnel, an upper pilot tunnel, a lowerpilot tunnel and lower-layer reserved core rock soil, a middle rock pillar is formed through the middle pilot tunnel, the upper pilot tunnel and the lower pilot tunnel; the middle pilot tunnel, an upper layer side pilot tunnel and a lower layer side pilot tunnel are excavated in sequence, a radial system anchor cable supporting structure and a radial system anchor rod supporting structure are installed; inclined anchor cables are arranged from the middle pilot tunnels on the two sides and the upper-layer side pilot tunnels on the two sides to be above the middle rock pillar in a driving manner, pre-reinforcing surrounding rocks above the middle rock pillar is carried out; a transverse opposite-pull anchor rod is driven into the middle rock pillar and reinforcing is carried out, prestressing force is applied to the anchor rod; the middle rock pillar is dismantled, simultaneously the radial system anchor rod supporting structure is installed; and the lower layer reserved core rock soil is dismantled. In the construction stage of the construction method of the ultra-flat cavern middle rock pillar supporting structure, a middle rock pillar supporting structure is reserved and is combined with a local bearing arch above the pilot tunnels, stable conversion of a surrounding rock overall stress system is achieved, a surrounding rock natural bearing arch is closed step by step, and safety construction of the ultra-flat cavern is achieved.

Description

technical field [0001] The invention relates to the technical field of building structures, in particular to a rock pillar support structure in an ultra-flat cavern and a construction method. Background technique [0002] In recent years, underground oil storage depots, underground tunnels, main workshops of hydropower stations, etc. are being built on a large scale at home and abroad, and rock mechanics has gradually become the focus of tunnel and underground engineering research. The typical super-long-span caverns built and under construction at home and abroad mainly include: Norwegian Gejovik City Ice Rink, Badaling Great Wall Station, etc. The Badaling Great Wall Station of the Beijing-Zhangjiakou High-speed Railway is the largest mountainous underground railway station in Asia. The single arch span is the largest underground excavated railway tunnel, and the span of the station hall reaches 45m. [0003] In order to meet the growing demand for underground space, the...

AI Technical Summary

Problems solved by technology

However, the additional beam-column system cuts the cavern space, which cannot meet the requirements of large-span and large-section space.

Especially for flat column-free caverns with relatively small span, as the span increases in magnitude, traditional design methods and concepts such as "CRD method" and "New Austrian method" can no longer meet the design requirements and cannot provide Reference and guidance

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