Multi-level fully-closed reinforcement technology of exposed fault zone of excavated side slope

Abstract

The invention discloses a multi-level fully-closed reinforcement method of an exposed fault zone of an excavated side slope, which comprises the following steps: after the side slope is excavated, immediately spraying concrete in the exposed fault zone to close the excavated slope; supporting the exposed fault or the broken rock of the side slope by adopting self-advancing anchors and consolidation grouting; then, applying a slope-sticking reinforced concrete panel in the exposed fault zone of the side slope to permanently close the zone, and burying drain holes, system anchors and orifice pipes of anchor cables in advance before casting; and finally, carrying out construction of the drain holes, the system anchors and the prestressed anchor cables to finally realize multi-level fully-closed reinforcement of the exposed fault zone of the side slope from the outside to the inside. The invention can be used for reinforcing the excavated side slope which has the defects that the fault has wide exposed range, low strength and poor properties, can be softened and collapsed easily in water, has large plastic deformation when the anchor cables are tensioned and can not be applied with prestress, thereby furthest improving the overall stability and the reinforcement effect of the side slope.

Description

technical field [0001] The invention belongs to the technical field of geotechnical reinforcement engineering, and in particular relates to a multi-layer fully-closed reinforcement method for excavating a side slope fault exposure area. Background technique [0002] Most of the large-scale hydropower, railway and highway infrastructure projects currently under construction or to be constructed in my country are located in alpine and canyon areas. These areas often have high and steep slopes, severe unloading and weathering of rock masses, and faults and dikes often develop inside the slopes. Structural surfaces such as unloading cracks, faults and other geological defects after slope excavation are exposed on the excavation slope, forming dangerous rock mass, which seriously affects the stability and safety of the excavation slope. [0003] In the reinforcement project of excavated slope, spray anchor support, prestressed anchor cable and frame beam-anchor cable are commonly ...

AI Technical Summary

Problems solved by technology

[0004] (1) When the traditional anchor-spray support is used, due to the broken rock mass in the exposed area of ​​the slope fault, the hole is easy to collapse and difficult to form when the drilling rig drills the anchor hole, and the anchor-spray support can only be carried out on the surface of the slope. Reinforcement, the depth and extent of reinforcement are limited

[0005] (2) When using anchor cables or frame beam-anchor cables for support, due to the poor fault properties, it is difficult to form holes for anchor cables and grooves for frame beams, and the construction time of anchor cables is relatively long, and the slope is affected by construction prone to landslides after disturbance and rainfall

[0006] (3) Due to the weak, broken and low strength of the rock mass in the fault and the affected zone, the rock mass near the anchor pier is prone to large deformation or plastic failure when the anchor cable is stretched, so that the anchor cable cannot be prestressed and it is difficult to reinforce the slope

[0007] (4) Because most of the fault rock mass is easy to soften and muddy when exposed to water, the traditional shotcrete is thin, which can only ensure the temporary closure of the excavation slope during the construction period; while the frame beam on the slope is not a closed structure, it cannot prevent Precipitation seeps into the fault fracture zone, therefore, the traditional support structure is difficult to ensure the long-term stability of the exposed area of ​​the slope fault fracture zone

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