Water-rich sand-cobble stratum shield entry and exit reinforcing system and construction method thereof

Abstract

The invention relates to a water-rich sand-cobble stratum shield entry and exit reinforcing system and a construction method thereof. A shield entry and a shield exit under the water-rich sand-cobble stratum condition often generate the phenomena that door sealing is failed, a soil body loses stability and collapses, and an ambient environment is destroyed. According to the system, station pit support structures are arranged on the outer sides of the inner walls, at the shield entry end and the shield exit end, of a station, glass fiber rib support piles are arranged within the range of shield tunnel structures, single row element secant piles are arranged outside the glass fiber rib support piles, and the shield tunnel structures are arranged on the outer sides of the single row element secant piles. According to the system, the glass fiber rib piles, the single row element secant piles and a dewatering well achieve the synergistic effect, the self-stability of a stratum and the integration of a shield and the soil body are fully utilized, therefore, implementation performance and safety of the shield tunnel entry and the shield tunnel exit are guaranteed, the construction risk is reduced, the method is easy to operate, investment is reduced, and construction implementation is promoted.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering structures, in particular to a shield tunnel reinforcement system for water-rich sand and pebble strata and a construction method thereof. Background technique [0002] Throughout the history of rail transit construction at home and abroad, for water-rich sand and pebble areas, shield tunneling often has problems such as serious engineering quality defects, slow project progress, and excessive project investment during the shield tunnel entry and exit process. Water-rich sand and pebble strata As a typical mechanically unstable stratum, the construction of shield tunnel access is often accompanied by serious engineering quality accidents. Therefore, the choice of reinforcement method for shield tunnel entry and exit is particularly important. [0003] Existing experience shows that shield access tunnels in water-rich sand and pebble formations often have sealing failures, soil instabil...

AI Technical Summary

Problems solved by technology

The main reason is that the water-rich sand and pebble formation is a typical mechanically unstable formation, with poor gradation and many large particles, forming a particle support structure with coarse-grained overlap and fine-grained interstitials, with low cohesion and sensitive formation response , the cutting of the shield cutter head can easily destroy the original relatively stable or balanced state and cause collapse, causing the excavation surface to become unstable and the cave wall to collapse. At the same time, due to the particle skeleton effect, it is easy to form cavities during construction and cause delayed settlement

Therefore, the conventional ground reinforcement method of shield tunnel entry and exit is no longer applicable, and corresponding adjustments are required

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