坝体槽挖静态破碎施工方案对比研究

Comparative study on construction schemes for static crushing construction technology for trenching-excavation of dam body

在丰满水电站全面治理(重建)工程中,老坝上游面固定系船柱布置于老坝坝体上游侧,系在老坝上游面48#、49#坝段分别开挖一道宽2.30 m、深1.80 m的槽状结构。因坝体上游面经历过多次防渗补强施工,坝体上游面由低到高依次为预制混凝土板、沥青混凝土、钢筋混凝土,面层设置有双层钢筋网,坝面表层结构复杂。开挖作业实施过程中经过多方案比选,底部沥青混凝土采用人工凿除,上方钢筋混凝土采取"绳锯机+无声破碎剂"相结合的开挖方案,在保证设计开挖体型尺寸的同时,有效保证了保留部分结构的完整、安全,为后续水库调度运行、新机组发电提供了可靠保障。

In the reconstruction project of Fengman Hydropower Station,the fixed bollards of the upstream face of the old dam are arranged at the upstream side of the old body of Fengman Dam,which are two trench-structures with the width of 2.30 m and the depth of 1.80 m excavated in the dam sections of No.48 and No.49 of the upstream face of the old dam respectively.Due to several times of anti-seepage reinforcement made on the upstream face of the dam body,the surface structure of it is complicated and consists of precast concrete slab,asphalt concrete,reinforced concrete and dual-layer reinforcing mesh on the surface layer.During the excavation construction,the excavation scheme,i.e.combining artificial-chiseling of the bottom asphalt concrete with excavating the upward side reinforced concrete with the method of wire saw+soundless breaking agent,is adopted;from which the integrity and safety of the structure of the reserved part are effectively guaranteed at the same time of ensuring the designed excavation size,and then a reliable guarantee for the subsequent operation of the reservoir and power generations of the new hydropower units is provided.