郎恒水电站右水源引水隧洞防渗补漏工程施工

根据郎恒水电站右水源引水隧洞衬砌混凝土裂缝的分布情况，对开裂较大的纵向裂缝，凿除开裂的混凝土后进行泵送混凝土回填；较小的纵向裂缝采取化学灌浆，封堵因裂缝产生的渗漏通道，同时通过固结的化学材料增强薄弱面的强度。回填混凝土达到设计强度70％后，对溶洞及连接衬砌段顶拱进行回填灌浆，使衬砌混凝土与围岩整体结合，漏水通道得到填充和封堵并降低顶拱2／3拱高处应力。工程完成后溶洞衬砌混凝土裂缝结合良好，渗漏流量减小，达到了预期目的。

Seepage prevention and leakage repairing construction for right water source diversion tunnel of Langheng Hydropower Station

At Langheng Hydropower Station, according to distribution of cracks on the concrete lining of right water source diversion tunnel, for the relatively big longitudinal cracks, pumping concrete backfill was conducted after the cracked concrete was chiseled off; chemical grouting was adopted at relative small cracks to close the leakage route while the consolidated chemical material can improve the strength of weak surfaces. When the strength concrete is up to 70% of design value, backfill grouting was carried out at arch roof of caves and of backfill connecting lined section, so as to render overall combination of concrete lining and surrounding rock, filling and sealing of leak- age passages, stress decease at two-thirds of arch height. After completion of construction, the expected objective is achieved with cracks on lining concrete combined well and decrease of leakage flow.