某引水隧洞聚脲防渗施工技术

某引水隧洞的结构为双层衬砌,各层具单独受力特性,渗水的排水方式为内水内排,隧洞在试运营后渗水量偏大,增加了运营成本并且给隧洞结构安全带来很大隐患。文章首先介绍了高压引水隧洞的聚脲防渗施工处理。喷涂双组分聚脲施工部位主要为隧洞内衬分段施工的环向接缝和预应力筋锚具槽处。其次,介绍了聚脲材料和底涂材料,并对聚脲喷涂技术施工工艺和施工要求进行了详细介绍,采用压水试验检查,黏结强度、聚脲厚度监测,证明采用聚脲喷涂防渗技术对高压水工混凝土的防护、防渗、降低运营成本和高水压引水隧洞在长期安全运营具有重大意义。采用聚脲喷涂防渗技术处理后,渗水量大幅降低。

Application of Polyurea Spraying in Seepage Control of a Water-conveyance Tunnel

The water conveyance tunnel under study has double layer lining structure, with each layer of lining undertaking the loads independently. The seepage water of the tunnel is drained along the tunnel towards outside. After the tunnel has been put into trial operation, it is found that the volume of the seepage water is large, which may increase the operation cost and may jeopardize the safety of the tunnel structure. Therefore, polyurea spraying is made for the circumferential joints and anchorage slots of the tunnel so as to control the water seepage. In the paper, the polyurea material, the prime coating material, the process and technical requirements of the polyurea spraying are presented in detail. Water pressure test is made to measure the bonding strength and thickness of the polyurea layer, which shows that polyurea spraying can achieve good effects. In the end, due to the polyurea spraying, the volume of the seepage water of the tunnel has been reduced significantly.