Carbonaceous schist tunnel blasting method and construction method

Abstract

The invention discloses a carbonaceous schist tunnel blasting method and construction method. The carbonaceous schist tunnel construction method includes the steps of carrying out blasting in the carbonaceous schist tunnel blasting method, clearing away residues and digging out rock mass which does not fall off by using mechanical equipment, and revising a tunnel contour line. The carbonaceous schist tunnel blasting method includes the steps of dividing a tunnel face into a carbonaceous schist area and a none-carbonaceous schist area; arranging a plurality of blast holes in the tunnel face to form a hole pattern, wherein the density of the blast holes in the carbonaceous schist area is smaller than that of the blast holes in the none-carbonaceous schist area; filling explosives and detonators into the blast holes; connecting the detonators into a network; detonating the explosives according to a preset detonating sequence. The tunneling method of combining blasting and machinery is adopted, blasting is carried out first, rock does not need to be thrown out completely, and therefore disturbance and damage to surrounding rock are reduced; then the residues are cleared away and the rock mass which does not fall off is dug out by using the mechanical equipment, thus, tunneling efficiency can be improved, disturbance to the surrounding rock is little, and damage on the surrounding rock is reduced; in addition, the back break control effect is good, the tunneling effect is improved, and tunneling quality is high.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering excavation, in particular to a carbonaceous schist tunnel blasting method and construction method. Background technique [0002] During the excavation of tunnels, some special and complex geological conditions are often encountered. For example, in the Huashigou Tunnel of Shibai Expressway, a large area of ​​carbonaceous schist appeared during the excavation process. Carbonaceous schist has the characteristics of large amount of deformation, long duration of deformation, non-convergent deformation, and sensitivity to blasting vibration. During construction, problems such as collapse or deformation encroachment are prone to occur, and it is difficult to achieve good results by general methods. [0003] Domestic tunnel construction generally adopts drill and blast method or mechanical excavation method. The drilling and blasting method greatly disturbs the surrounding rock, and often aff...

AI Technical Summary

Problems solved by technology

The drilling and blasting method greatly disturbs the surrounding rock, and often affects the stability of the rock mass due to excessive vibration, causing disasters, and the blasting effect is not ideal, the arch is easy to fall off, serious over-excavation, and carbonaceous schist is highly sensitive to blasting. Blasting vibration can easily cause large deformation of surrounding rock

The mechanical excavation method has higher excavation efficiency in soft rock, less disturbance to the surrounding rock, high excavation quality, and regular tunnel contours. Accounting for more than 90% of the entire face area, sometimes only about 20%, the machine cannot effectively dig out non-schist rock mass, so the efficiency is not high

At present, there is no mature method for the excavation of carbonaceous schist tunnels in the existing technology

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