A large-scale karst cave treatment and excavation method across the tunnel body

Abstract

The invention relates to a method for processing and excavating a large cave crossing through a tunnel body. The method comprises the steps of processing the cave; grouting in advance; excavating an arc-shaped pilot tunnel on the upper part; excavating the middle steps; excavating the lower steps; excavating the three layers of steps on the middle part. According to the method provided by the invention, the construction space is large; the mechanical construction is convenient; the parallel operation of multiple operation planes can be performed; the work efficiency is higher; the construction process can be flexibly and timely switched and the construction method can be adjusted when the geological conditions are changed; the method can adapt to different spans and various section forms; the primary lining process operation is convenient; on the basis of step-method excavating, the core soil is reserved, left and right staggered excavating is performed and the stability of the excavating plane is benefited; when the deformation of the surrounding rock is large or sudden, the closing time can be adjusted as soon as possible under the conditions of ensuring safety and meeting clearance requirement; the method can be widely applied to the tunnel excavating construction for quickly, safely and effectively passing the geological conditions on the stratum under special geological conditions of the cave, so as to ensure the construction and tunnel safety.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a method for treating karst caves and excavating large karst caves when tunnel excavation encounters deep dredging and full filling of large karst caves. Background technique [0002] The formation of caves is the result of long-term dissolution of groundwater in limestone areas. The insoluble calcium carbonate in limestone can be converted into slightly soluble calcium bicarbonate by the action of water and carbon dioxide. This geological phenomenon will affect the stability and mechanical distribution of surrounding rock, and affect the quality of surrounding engineering construction. [0003] In engineering construction, some construction techniques have a great influence on the stress distribution of surrounding rocks. Unavoidable karst caves are encountered, unsafe and unstable factors of engineering structures increase, construction techniques become complicated, and the ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a large-scale karst cave treatment and excavation method that traverses the tunnel body. It is necessary to solve the problem that the existing tunnels have a long construction time when passing through the karst cave, which is not conducive to timely adjustment of the closing time, and is inconvenient for mechanical construction and construction. Technical problems of frequent process changeover

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