金河水电站调压井开挖施工技术管理

Excavation of surge shaft at Jinhe hydroelectric project and supervision of construction

西藏昌都金河水电站调压室工程由调压井和交通洞组成,整个范围山体历经多次构造运动,围岩破碎且覆盖层深厚。受场地和地质条件制约,无法采用大型洞挖机械设备快速掘进,实际需按超短正台阶的小进尺方法进行洞挖施工。为此,施工中采用了无支撑棚架上行掘进技术,解决了竖井开挖中常规施工技术不能解决的困难和因交通洞等地质原因在处理施工时所延误工期带来的不利影响,较原方案缩短工期35d,降低了施工成本。

the surge chamber ol the Jinhe hydroelectric project at Changdu, Lhasa, Tibet, is composed ot surge shaft and traffic tunnels. The mountainous area in question had been subject to tectonic movement. The surrounding rocks are highly fractured covered with thick overburdens. Restricted by the geological conditions, it is impossible to use heavy tunneling machines here. Therefore the support-free platforms were used to do excavation upward. It solved the problem often occurred during excavation by conventional method and negative impact caused by delays due to access tunnels. The construction duration had been reduced by 35 d, at a lower cost.