Step type excavating method for large unloading loose rocky side slope

Abstract

The invention discloses a step type excavating method for a large unloading loose rocky side slope and belongs to the technical field of side slope excavating of civil construction. By the method, when the large unloading loose rocky side slope is excavated by the current pre-splitting blasting excavation technology, the integrity and the stability of a surface rock mass of the rocky side slope can be improved, and a collapse accident of the surface rock mass of the rocky side slope which is caused by construction can be also prevented. The method comprises the following steps of drilling drilled grout holes in the large unloading loose rocky side slope to be excavated, filling protective slurry into the large unloading loose rocky side slope through the drilled grout holes, after the protective slurry is diffused in the rock mass to form a cured protecting layer, performing pre-splitting blasting excavation, supporting the first-grade side slope which is excavated, and repeating the steps until the whole large unloading loose rocky side slope is excavated.

Description

technical field [0001] The invention relates to a step-type excavation construction method, in particular to a step-type excavation construction method for a large-scale unloading loose rock slope, and belongs to the technical field of slope excavation in civil construction. Background technique [0002] my country is a mountainous country, and many infrastructure projects such as water conservancy and hydropower, railways, highways and mines are often located in alpine and canyon areas, and the construction of these projects often involves the excavation of rocky slopes. However, under the influence of geological structure and long-term physical, chemical and biological weathering and erosion, the slope rock mass near the surface often becomes weak and broken, with low strength and easy to soften when exposed to water. At the same time, faults often develop inside the slope , dikes, unloading cracks and other weak structural planes. Therefore, when the slope is excavated, ...

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Problems solved by technology

[0004] (1) The traditional slope pre-splitting blasting excavation method will cause further loosening of the loose and broken rock mass, reducing the stability of the slope;

[0005] (2) The traditional slope pre-splitting blasting excavation method carries out the construction of slope protection measures such as hanging nets, shotcrete, and anchor rods after the excavation is completed. Due to the long support construction time, the unsupported slope is exposed for a long time , further leading to the deterioration of slope rock mass;

[0006] (3) When the rock mass of the slope is relatively broken, it is difficult to construct the hole by blasting in the traditional slope pre-splitting blasting excavation method, and it is easy to drop and stick the drill, while the drilling with the pipe is expensive;

[0007] (4) When the slope rock mass is relatively broken, the traditional slope pre-splitting blasting excavation method is likely to cause over-excavation and under-excavation, the quality of the slope surface is not good, and even secondary treatment is required, which is half the effort with twice the effort;

[0008] (5) When the rock mass of the slope is relatively broken, it is also difficult to form holes with the support of anchor rods or anchor cables after excavation on the slope surface

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