Convergent mechanism of roadway driven along with strong roof of special thick stratum and its controlled measures

• 来源期刊: 煤炭学报（英文版）
• 年，卷（期）: 2004,（1）
• 页码范围: 1-4
• 页数: 4页
• 语种: 英文

摘要

The trapezoidal cross-section roadway, driven along with its medium and fine grain sandstone roof in special thick stratum, was situated in shale strata. Rock-lining wall was employed in roadway, which its roof is in the free situation. Under the action of virgin stress, the surrounding rock of roadway was in stability. While under the action of fixed abutment pressure arisen from protection pillar of roadway, which its two sides' seams were extracted, free strong roof of roadway was in the stability. But its two sides' rock-lining walls was fractured, partially broken into pieces, and its floor heave was obvious. The velocity of floor heave is 0.4～0.8 mm/d. The size of broken zone of surrounding rock of roadway increases doubly. An effective load coefficient of surrounding rock to was quoted illustrate these phenomena. The main reasons of roadway convergence are that, rock property of surrounding rock is inferior, protection pillar affects its stability, and supporting pattern employed is improper. At last, effective measures to control roadway convergence should be bolting and grouting lining, which mainly consolidates surrounding rock of roadway.