Method for preventing and controlling landslide risk of side slope at mountain road tunnel portal

Abstract

The invention discloses a method for preventing and controlling the landslide risk of a side slope at a mountain road tunnel portal. The method comprises the steps of 1, extending an open cut tunnel out of a landslide risk area of the slide slope, and injecting double-liquid slurry to the bottom of a foundation of the open cut tunnel for reinforcing; 2, adding a foam cushion layer with the thickness ranging from 10cm to 20cm to the outer side of the open cut tunnel, wherein the foam cushion layer is used for buffering impact of backfilled earth and rocks against the open cut tunnel; 3, synchronously backfilling earth and rocks at the two sides of the open cut tunnel till the height of the backfilled earth and rocks at the top of the tunnel is greater than one time the diameter of the tunnel and a lower cut of a sliding face, subjected to landslide, of the side slope is covered; and 4, if other sliding faces exist above the slide face mentioned in step 3, excavating away par of sliding blocks and filling the sliding blocks to the two sides of the open cut tunnel symmetrically and the top of the tunnel, and covering lower cuts of other sliding faces 1m above in height. The method targets at the landslide risk of the side slope of the tunnel portal; the combined mode that the foundation is reinforced, the open cut tunnel is extended, the earth and rocks are synchronously backfilled and part of the sliding blocks are excavated away for filling is adopted; the landslide risk of the side slope is controlled; and the method has the beneficial effects of being low in cost, little in occupied land, high in construction safety and the like.

Description

technical field [0001] The invention belongs to the field of construction methods, and in particular relates to a method for preventing and controlling the risk of landslides and collapses at the entrance slope of a road tunnel in a mountainous area. Background technique [0002] Many mountain road tunnels built in my country in the 1980s and 1990s shortened the length of the tunnel and formed a cutting slope at the entrance to save money, but it also caused the risk of landslides at the slope of the tunnel entrance. In the prior art, there are many prevention and control methods for slope landslide risks, such as anchor rod or anchor cable reinforcement, anti-slide pile support, excavation of sliding blocks for unloading and reinforcement, and extension of open holes. However, due to the complex factors involved in the slope collapse, simple mechanical application of existing methods cannot solve the problem very well, and may easily lead to secondary accidents. Especially...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem that there is a risk of landslides on the slope of the tunnel entrance of the existing mountain road shortening, directly analyze the risk of landslides on the slope of the tunnel entrance of the mountain road by mechanical methods, and provide a safer and more stable mountain road tunnel entrance. Prevention methods for slope landslide risk

Images