Tunnel three-step synchronous excavation construction method based on partition explosion

Abstract

The invention discloses a tunnel three-step synchronous excavation construction method based on partition explosion. Excavation construction is performed on a construction tunnel according to a plurality of excavation sections from back to front. The method comprises the following steps of 1 surveying and setting-out, 2 drill explosion construction, 3 upper hole excavation, 4 middle hole excavation, 5 lower hole excavation, 6 next excavation section excavation construction, 7 repeated execution of the step 6 till all the excavation construction processes of the construction tunnel are completed. The design is reasonable, construction is easy and convenient, and the using effect is good, explosion region division is performed on an upper explosion region and a middle explosion region, the arrangement positions of shot holes inside the explosion regions are limited, the phenomena that when the large-section one-time explosive load is excessively large, intensive vibration is generated byexplosion, and tunnel faces collapse or vaults collapse can be effectively avoided, it is ensured that the tunnel excavation process is safe and reliable, and the tunnel structure stability can be ensured; and meanwhile, by adopting the three-step synchronous excavation mode, the weak surrounding rock penetrating tunnel excavation process can be safely and successfully completed.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a tunnel three-step synchronous excavation construction method based on zoned blasting. Background technique [0002] In the construction process of railway and highway tunnel projects, due to the limitation and influence of geological conditions, it will cause great influence and difficulties to the construction during the construction process. In the process of tunnel construction, various combinations of rock formations are often encountered, such as weak and uneven surrounding rock, shallow buried bias landform, soil-rock mixed geology and so on. For the excavation and support of tunnels that pass through soil-rock mixed strata (also known as soil-rock interface geology or soil-rock boundary strata), at present, the main methods in China are advanced pipe shed grouting support, advanced horizontal jet grouting pile reinforcement, and controlled excavat...

AI Technical Summary

Problems solved by technology

During the actual tunnel construction, the main problems of tunnel excavation in the soil-rock boundary stratum are as follows: first, the hardness of the rock and soil is not uniform, and the blasting of the weathered rock layer in the lower part will easily cause the upper soil layer to collapse, which is harmful to the construction personnel; second, the groundwater The enrichment area further softens the soil-rock boundary strata, causing serious deformation of the surrounding rock; third, the swelling of the expansive soil with water causes the primary support to deform and crack, and in severe cases, the deformed structure of the primary support arch will be damaged and the support capacity will be lost

Once the corresponding reasonable support measures are not adopted in the actual construction or the excavation method is improper, it is very likely to cause deformation of the support in front of the face of the tunnel, and even serious consequences of collapse

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