复杂地质条件下高边坡开挖及防护措施综合应用——以密云水库第一溢洪道改建工程为例

Comprehensive Application of High Slope Excavation and ProtectionMeasures under Complex Geological Conditions: A Case Study of the First Flood Discharge Channel Reconstruction Project at Miyun Reservoir

密云水库是一座以防洪、供水为主,综合利用的大型水利工程。第一溢洪道是密云水库主要的泄洪建筑物,两侧为陡峭山体,破碎带较多,地质情况复杂,工程开挖最高高度达50m,在改建工程中边坡开挖与支护施工难度大。在工程典型部位进行了试验性开挖和支护施工,高边坡分级开挖,分级支护,采用静态破碎和机械相结合方式开挖边坡,对于不同地质条件选取最优支护措施。目前,溢洪道边坡部分竣工已3年,巡视检查及仪器监测显示边坡运行状况良好。该施工方式保证了施工期和运行期工程安全,可为今后类似溢洪道工程施工提供参考。

Miyun Reservoir is a large-scale water resource project primarily used for flood control and water supply.The first flood discharge channel is the main flood discharge structure of Miyun Reservoir,flanked by steep mountainsides with numerous fractured zones,making the geological conditions complex.The maximum excavation height for this reconstruction project reaches 50 meters,posing significant challenges for slope excavation and support construction.Experimental excavations and support construction were conducted at typical project sites,with the high slopes excavated and supported in a phased manner.A combination of static blasting and mechanical methods was employed for slope excavation,and optimal support measures were selected for varying geological conditions.Currently,three years after the completion of the slope section of the flood discharge channel,regular inspections and instrument monitoring indicate that the slope is in good operational condition.This construction approach has ensured the safety of both the construction and operational phases of the project and can serve as a valuable reference for similar flood discharge channel projects in the future.