Method for ventilating drainage tunnel of extremely-long double-hole tunnel of expressway during construction

Abstract

The invention discloses a method for ventilating a drainage tunnel of an extremely-long double-hole tunnel of an expressway during construction. Before a drainage transverse channel is opened at the initial stage of constructing the drainage tunnel, a requirement of ventilating the drainage tunnel is met during construction by a press-in ventilation method; after the drainage tunnel is forwards pushed, and drainage transverse channels are opened, fresh air in a flat pilot tunnel is pressed into a tunnel face of the drainage tunnel through an axial flow fan at the drainage transverse channel, which is closest to the tunnel face, of the flat pilot tunnel; a jet flow fan is arranged between the opening of the drainage tunnel and the last drainage transverse channel so as to introduce fresh air into the drainage tunnel; a jet flow fan is arranged in the last drainage transverse channel of an air outlet tunnel so as to introduce air from the opening of the drainage tunnel and the tunnel face into the air outlet tunnel, and the fresh air is discharged by the air outlet tunnel; most paths of the inlet and outlet air are respectively changed into the whole flat pilot tunnel of a main tunnel and the air outlet tunnel from the drainage tunnel; and the sections of the inlet and outlet air are increased, the resistance is reduced, the ventilation effect is good, the air quality of the drainage tunnel at various sections is good, the requirement for ventilation of the drainage tunnel of the extremely-long double-hole tunnel of the expressway during construction is met.

Description

technical field [0001] The invention relates to a construction ventilation method for a small-section tunnel, in particular to a construction ventilation method for a drainage tunnel of an extra-long double-hole tunnel on an expressway. Background technique [0002] During the construction of highway tunnels, due to the explosion of explosives, the use of internal combustion machinery, the release of harmful gases in the ground during excavation, and the breathing of construction workers, the air in the tunnel is very dirty, which has a serious impact on the physical and mental health of the human body, so it must be carried out. The tunnel construction is ventilated, and the poisonous and harmful gases in the tunnel are kept in time. [0003] For expressway extra-long double-hole tunnels, roadway ventilation is usually adopted. as attached figure 1 , it is to use one of the tunnels as a flat guide tunnel (2) for entering fresh air, and the other tunnel as a wind tunnel (3...

AI Technical Summary

Problems solved by technology

Due to the small design section of the drainage tunnel, the long ventilation distance of a single port, and the small effective space, the size of the fan and ventilation pipe is limited, and it is difficult to quickly replace a large amount of harmful substances instantly produced by the blast on the tunnel surface with fresh air; It is also difficult to remove the exhaust gas discharged along the way in time; in addition, the drainage hole has a large slope from the outside to the inside, making it difficult to exhaust the smoke in reverse

In short, the existing press-in ventilation method has poor ventilation efficiency and ventilation effect, and it is difficult to meet the ventilation needs of the drainage tunnel construction and transportation of super long double-hole tunnels on expressways

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