Tunnel double upper sidewall heading construction method

Abstract

The invention provides a tunnel double upper sidewall heading construction method. When a tunnel is excavated, the cross section of the tunnel is divided into a first heading, a second heading and an upper core soil; a No.1 lower step and a No.2 lower step are excavated in different time; and a boundary of the first heading and the No.1 lower step, and a boundary of the second heading and the No.2 lower step are springing lines. The method has the advantages that: the cross section of the tunnel is divided into an upper part and a lower part by taking the springing line as a boundary, wherein the upper part is constructed by an improved double sidewall heading method; the tunnel with a large section is divided into a left heading and a right heading to be constructed one after another immediately, and the core soil is excavated by sloping, so that the excavation section span is reduced and the supporting effect of the core soil is achieved; and the lower part is divided into a left part and a right part to be constructed one after another; an invert arch and a filler course are constructed timely; and the secondary linings of an arch wall and an arch crown are constructed finally so as to enter a common working condition together with surrounding rock and primary supports.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a method for tunnel construction by the double-upper-side-wall pilot pit method. Background technique [0002] Tunnel construction generally adopts the double-side wall pilot tunnel method, also known as the double-side wall pilot tunnel method or the glasses construction method. It belongs to a branch of the New Austrian Law and is based on the basic principles of the New Austrian Law. The basic principle of the new Austrian method of construction: make full use of the self-supporting capacity of the surrounding rock and the space constraints of the excavation surface, and use anchor rods and shotcrete as the main support means to reinforce the surrounding rock in time to restrain the relaxation and expansion of the surrounding rock. deformation, and guide the design and construction of underground engineering through the monitoring and measurement of surrounding rock and sup...

AI Technical Summary

Problems solved by technology

Although the double-side-wall pilot pit method has many excavation sections with large disturbances and takes a long time to close the entire section for the initial support, each block is closed immediately after excavation, so there is almost no deformation during construction. develop

The construction of the double side wall pilot pit method is safe, but the speed is slower and the cost is higher

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