Arrangement method of compression arch of pre-stressed anchor rod in deep soft and weak rock large section roadway

Abstract

The invention discloses an arrangement method of a compression arch of a pre-stressed anchor rod in a deep soft and weak rock large section roadway. The method primarily aims at the deep soft and weakrock large section roadway, wherein the roadway burial depth H is greater than or equal to 800.0 m, the lithologic adhesive force c of the coal rock is equal to 0.6-1.5 MPa, and the internal frictionangle phi is equal to 16-28 degrees. The method is primarily used to determine supporting parameters of the pre-stressed anchor rod in the deep soft and weak rock large section roadways with different lithologic properties selected to carry the compression arch effectively and reasonably, wherein the supporting parameters include anchor rod pretightening force, reasonable anchor rod length, reasonable array pitches among the anchor rods and the like. The invention relates to the technical field of arrangement of the anchor rod of the roadway. The arrangement method of the compression arch ofthe pre-stressed anchor rod in the deep soft and weak rock large section roadway solves the problem that the effective compression arch is hardly formed or the compression arch is hardly carried reasonably in engineering as long anchor rods with lengths L being equal to 2800 mm and wide separation distance anchor rods with array pitches being a*b approximately equal to 800mm*800mm are arranged inthe large section roadway in an existing mining area and the anchor rod pretightening force F is approximately equal to 80 kN and lithologic changes are not considered.

Description

technical field [0001] The invention relates to the technical field of bolt arrangement in roadways, in particular to a method for arranging prestressed bolt compression arches in large-section roadways in deep soft coal and rock. Background technique [0002] Deep large-section soft rock roadways are common in the Lianghuai mining area in Anhui and other mining areas across the country. For roadways buried deep (generally H≥800m), surrounding rock lithology is poor (cohesion c=(0.7-1.0) MPa, internal friction angle φ=(18°~22°)) and the roadway section is large (S≥16m 2 ) deep soft coal-rock large-section roadway, the thickness of the surrounding rock loose circle generally satisfies L P ≥3000mm, such as figure 1 , for L P ≥ 3000mm large loose ring thickness deep weak coal rock, currently widely used prestressed bolt (cable) and other combined support, the prestressed bolt effect makes the soft coal rock in a certain range of the shallow layer of the roadway form a compre...

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Problems solved by technology

[0004] Aiming at the deficiencies of the prior art, the present invention provides a method for arranging prestressed bolt compression arches in deep weak coal and rock large-section roadways, which solves the problem that the bolt length L=2800mm is commonly used in existing mining areas for large-section roadways. Anchor bolts, row spacing a×b≈800mm×800mm wide spacing anchor arrangement, anchor preload F≈80kN and lithological changes are not considered, it is difficult to form effective compression arches or reasonably bear compression arches in engineering

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