Through research, the designed scheme of upward excavation and concrete placement in adit was changed to downward excavation and stratified concrete placement for structural blocks of wide shaft well, fullfiling the design requirement.

• 为此,经研究将原设计的由下向上平洞开挖浇筑混凝土方案改为以宽竖井为结构分块单元的由上向下开挖和由下向上分层浇筑混凝土的施工方案,达到了设计效果。