猴子岩水电站高地应力厂房边墙开挖技术研究

Excavation technology of side wall of Houziyan Hydropower Station powerhouse in high in-situ stress area

猴子岩水电站地下厂房存在跨度大、地应力高、周边相邻洞室多、岩体挖空率高、高边墙变形问题突出等特点。介绍了地下厂房高边墙施工的程序、工艺、方法及施工要点。阐述了施工中遇到的重大技术问题及应采取对策措施。工程实践表明,合理的施工通道和开挖分层布置,实施"立体多层次,平面多工序"的施工方法,严格遵循"弱爆破、快速封闭、及时锚固"的作业程序,采用"深层预裂、浅层开挖"的施工工艺,强化物探及安全监测的反馈分析,及时采取加强支护措施,才能够确保猴子岩地下厂房高边墙稳定性。

The underground powerhouse of Houziyan Hydropower Station is characterized as large span, high geo -stress, many adjacent caverns in the surrounding area, large excavation ratio in rock mass and large deformation of high side wall. The procedure, technology, method and key points in construction of high side wall of underground powerhouse were introduced. The major problems in the construction and countermeasure are presented. The engineering practice showed that the stability of high side wall of powerhouse can be ensured by the following measures：reasonable layout of construction passage and excavation lay-ers, multiple vertical layers construction and multi-procedure construction in plane, weak explosion, quick sealing and timely anchoring, deep presplitting and shallow excavation, strengthening feedback analysis of geophysical prospecting and safety moni-toring, timely adopting supporting measure.