Process for construction of piled raft in low-buried and unsymmetrical pressure flexible plastic karst tunnel

Abstract

The invention discloses a process for construction of a piled raft in a low-buried and unsymmetrical pressure flexible plastic karst tunnel. The process is characterized in that the piled raft structure is adopted in the low-buried and unsymmetrical pressure flexible plastic karst tunnel for crossing a karst cave; the piled raft structure is composed of cast-in-place piles (1) on the lower portion and a raft plate (2) on the upper portion, and the cast-in-place piles and the raft plate are connected through steel bars; the cast-in-place piles (1) are reinforced concrete bored cast-in-place piles, and the raft plate (2) is a C35 corrosion-resistant reinforced concrete raft plate; steel reinforcement cages are used in the bored cast-in-place piles, are machined through a jig molding method, and are hoisted by a drilling machine to be installed in a sectioned connection mode. By the adoption of the process, karst tunnel foundation blockage, reinforcement construction difficulties and other technical problems concerning tunnel construction safety and quality are solved.

Description

technical field [0001] The invention relates to a construction technique of pile rafts in a shallow-buried bias-pressure soft plastic body karst tunnel. Background technique [0002] Limestone formations are widely distributed in my country, and karst geology is very common. When the tunnel passes through the karst formation, some caves are located at the bottom of the tunnel, the filling is soft and deep, and the tunnel base is difficult to handle; some caves have broken rocks and are prone to collapse; Or a large amount of sediment mixed with water poured into the tunnel; sometimes when the filling tank filled with water is encountered, when the tunnel is excavated to its edge, the water-containing filling keeps pouring into the tunnel, which is difficult to stop, and even the surface cracks and sinks. The pressure increased sharply; some karst caves and underground rivers were circuitous and criss-crossed, with intricate branches and a wide range, so it was very difficul...

AI Technical Summary

Problems solved by technology

[0003] The problem to be solved by the present invention is to provide a construction process of pile rafts in shallow-buried bias-pressured soft plastic karst tunnels, so as to overcome the deficiencies related to tunnel construction safety and quality, such as karst tunnel base blockage or reinforcement construction difficulties.

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