关于地下洞室喷混凝土支护效果的实践与探讨

Discuss on Protective Effects of Insufflations of Grotto Concrete Layer and its Practice

地下洞室开挖后，在地应力、不利地质结构面和施工等因素影响下，围岩表面常发生岩爆、片帮、剥落、掉块及局部塌方等现象。拉西瓦水电站引水发电系统地下洞室的开挖支护经验表明，混凝土喷层的作用，只有在其粘结力得到保证的情况下才能充分发挥。网喷混凝土很少脱落，防止岩爆的效较好，比钢纤维喷混凝土较之安全、经济。

When excavation of Grotto undertaking, some failures would appear on the surface of wall rock, such as rock burst, rib spalling, peel, rock drop and landslide etc. It was shown by grotto excavation experience of water diversion of Laxiwa hydropower station project that the insufflate layers of concrete play a function role only when the cohesive force was ensured. The insufflate concrete with steel net was not hreaked off for rock burst prevention, of which the safe and economic features were better than that of insufflate concrete with steel fiber.