The initial support structure and construction method of the high side wall anchored and pulled in the underground structure of the underground structure in the rock formation

Abstract

The invention belongs to the technical field of design and construction of tunnel and underground engineering, and particularly relates to a high-side-wall anchored primary support structure for a rock strata underground excavation underground structure, and a construction method of the high-side-wall anchored primary support structure. The high-side-wall anchored primary support structure is characterized in that the surface of a steel pipe pile and an adjacent steel pipe pile are sealed through a spray concrete surface layer; the tops of the steel pipe piles are vertically connected through a top ring beam; a ring beam grouting steel pipe is embedded into the top ring beam; a ring beam prestress anchor cable and a steel pipe pile prestress anchor cable are vertically arranged; one end of the ring beam prestress anchor cable is mounted on the top ring beam and locked by a ring beam fixing part; the steel pipe pile prestress anchor cable is positioned below the ring beam prestress anchor cable; the ring beam prestress anchor cable is fixed to the spray concrete surface layer through a concrete fixing part. The high-side-wall anchored primary support structure is suitable for a straight sidewall primary support structure of a large cross tunnel and an underground structure which are arranged at the weak fractured rock strata.

Description

technical field [0001] The invention belongs to the technical field of design and construction of tunnels and underground engineering, and in particular relates to a high-side-wall anchor-drawn initial support structure and a construction method of an underground structure excavated in a rock formation. Background technique [0002] With the development of economic construction and national defense, the development and application of large-space underground structures that can meet different functions are increasing in my country's urban construction, such as subway stations, underground factories and civil air defense projects. [0003] In the construction of large underground structures in rocky strata, the horizontal lateral pressure is generally limited. In order to facilitate use, save investment and facilitate construction, arched cross-section structures with straight side walls are usually used. Under the condition of good surrounding rock and deep burial, the new Au...

AI Technical Summary

Problems solved by technology

This resulted in a significant increase in the amount of abandoned engineering, and at the same time, the setting of horizontal and vertical temporary supports seriously affected the construction space and construction progress, and the work efficiency was extremely low, and large-scale mechanized construction could not be realized.

Moreover, it is difficult to keep the temporary support of the lower layer of the tunnel and the upper layer before the subsequent blasting, and in severe cases, it will cause safety accidents due to the damage of the temporary support by blasting

[0006] The traditional straight side wall adopts the steel frame shotcrete structure. During the construction, the leg construction needs to be carried out according to the height of each excavation. The excavation of each step height has a working condition where the bottom of the side wall is suspended, and the arch structure is enlarged. and the subsidence and deformation of the formation, and there are certain safety risks

At the same time, after the excavation of the side walls of each step, it takes a certain amount of time to erect the grid and carry out the shotcrete construction, which is not conducive to the rapid sealing of the surrounding rock and the structure, and the construction process also has a certain overlap.

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