大变形隧洞不同支护方案支护效果的对比分析

为了探索在煤炭行业大变形巷道中使用的一种让压支护方案在大洞径永久运行隧洞中的支护效果和应用价值,以锦屏二级水电站输水隧洞为典型算例,采用数值模拟的方法对强支护、分层支护、让压支护进行对比分析。分析结果显示让压支护可有效释放围岩变形并控制塑性区发展规模,使围岩的应力、支护体受力状态得到有效改善,支护体安全系数有效提高。该支护结构同时具有强支护控制塑性区规模、分层支护释放围岩变形和压力的优点,是目前较为理想的大变形隧洞支护方案。

Analysis on supporting effects of different supports for large deformed tunnel

In order to research the supporting effect and application value of the application of a kind of yieldable support for the large deformed tunnel adopted within the coal industry to the permanently operated tunnel with large diameter， the numerical simulation is made for the comparative analysis among the reinforced support， layered support and yieldable support by taking the water conveyance tunnel of Jinping II Hydropower Station as a typical case. The analysis result shows that the yieldable support can effectively release the deformation of the surrounding rock and control the developing scale of the plastic zone， thus make effective improvements of both the surrounding rock stress and the stress status of the supporting body along with the effective enhancement of the safety factor of the supporting body. This kind of supporting structure has the merit of controlling the plastic zone with a reinforced support， while releasing the surrounding deformation and pressure with a layered supporting， and then is an ideal supporting method for the large deformed tunnel concerned.