A construction method for backfilling treatment of high-level tunnels passing through giant dissolved cavities

Abstract

The invention discloses a backfilling treatment construction method for a tunnel high crossing giant salt cavern. The bottom of a karst cave is processed; the karst cave is subjected to backfilling treatment through a construction guide hole, the karst cave is filled to a height which is flush with the level of the construction guide hole, and a layer of grout stop plate is constructed; backfill is dumped from hole entrances of two sides of a tunnel main hole and an entrance of pilot heading in the cave, and the backfill is back-filled to the bottom elevation of a main hole entrance; groutingand subsidence reducing are conducted on the backfill, and standing is conducted for a while after grouting; the top of the backfill is subjected to the construction of a cement graded crushed rock layer; after the construction completion of the graded crushed rock layer, drilling holes are formed in the karst cave backfill and bottom deposit settlement monitoring points, settlement monitoring isstarted, and standing is conducted for a period of time until monitoring data shows the settlement is stable; after monitoring shows that the settlement is stable and design requirements are met, a concrete road substrate is started to be constructed, large side walls are constructed on both sides of the concrete road substrate, outer karst caves of the large side walls continue to be back-filledby ordinary hole ballasts, an inner side is constructed as a tunnel open cut tunnel structure, and the entire karst cave process is completed.

Description

technical field [0001] The invention belongs to the field of solution cavity treatment, and in particular relates to a backfill treatment construction method for a tunnel passing through a giant solution cavity at a high position. Background technique [0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] With the development of tunnel construction technology, the construction is faced with a variety of complex terrain and landforms, especially in the tunnels built in Southwest China, which often expose large dissolved cavities. Most of the existing solution cavity treatment technologies are aimed at small and medium-sized solution cavities, and there is currently a lack of mature construction treatment methods for large solution cavities that pass through high tunnels; existing large solution cavities are mostly backfilled by concrete pouring. The cost of the method is very...

AI Technical Summary

Problems solved by technology

Most of the existing solution cavity treatment technologies are aimed at small and medium-sized solution cavities, and there is currently a lack of mature construction treatment methods for large solution cavities that pass through high tunnels; existing large solution cavities are mostly backfilled by concrete pouring. The cost of the method is very high, and it is easy to cause concrete cracking due to the heat of hydration; in the existing giant solution cavity backfill treatment technology, there is no good combination of solution cavity backfill and settlement monitoring, and there is a lack of feedback information to guide the backfill construction

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