大型地下洞室高边墙稳定施工技术研究及应用

The Study and Application of Large Underground Chamber/Cavern High Side Wall Stable Construction Technology

针对彭水电站高边墙岩性本身具有自稳时间短、抗风化能力弱,破坏机制具有突然性,不易被检测设施所掌控等特点,首次从岩体卸载的角度着手,采用薄层开挖随层支护、系统地应用钢质楔头预应力中空注浆锚杆和以钢垫板替代混凝土锚墩头新技术、通过无盖重固结灌浆加固处理、无裂缝预应力岩锚梁施工等创新技术,有效地控制了洞室高边墙围岩的开挖卸荷变形、确保了布置在高边墙上岩锚梁结构的稳定,实现了高效快捷的工程建设目标。填补了国内外大型地下洞室在陡倾角、薄层顺岩层走向布置的高边墙稳定施工技术领域的空白。

The high side wall of Pengshui hydropower project is characterized by short self- stabilizing time, low weathering - resistant capability and abrupt occurrence of rupture in terms of its rock properties. In view of this, unloading deformation in excavation of the chamber high side wall surrounding rock is effectively controlled, the rock bolt beam structure arranged on the high side wall is stabilized and thus the target of completing the project in an effective and quick way has been achieved by applying new technology such as load releasing of the rock mass, excavation in thin layers with timely support one by one, systematically installing of steel wedge pre - stressed middle grout injecting anchor rods, replacing a concrete anchor pier head by a steel stay plate, reinforcing by no - load consolidation grouting and use of non - crack pre - stressed rock bolt beams, which fills in gaps in construction technology of stabilizing high side walls of underground chambers/caverns with a steep dip angle that are arranged along the strike of rock formations at home and abroad.