【作者】 张云生； 罗孝明； 陈及新； 杨光亮； 张金海；

【Author】 Zhang Yunsheng, Luo Xiaoming, Chen Jixin, Yang Guangliang, Zhang Jinhai (China Hydropower Kunming Investigation.Design and Research Institute Kunming Yunnan 650051; Yunnan HuaNeng Lanchang River Xiaowan Hydropower Project Construction and Management Bureau Yunnan Nanjian 675702)

【机构】 中国水电顾问集团昆明勘测设计研究院； 云南华能澜沧江水电有限公司小湾工程建设管理局；

【摘要】 小湾工程岸坡陡峻、节理裂隙较发育、河谷狭窄,围堰地基为深厚强透水层,渗透量较大,地质条件复杂、施工干扰大、施工工期短;防渗技术处理极为困难。对强透水层采用堵漏和阻渗方法进行系统研究,在进行渗控理论计算的同时,开展了现场高喷灌浆、混凝土防渗墙和可控帷幕灌浆现场生产性试验,提出了堰基防渗结构形式。堰基防渗处理后,经大坝基坑开挖检验,上、下游围堰堰基防渗施工质量良好,防渗效果明显, 基坑渗水量小,现场实测统计日渗水量仅200 m3～300 m3。工程防渗结构形式研究成果,为西南地区高山狭谷、深厚复杂的堰基防渗结构形式提供了很好的借鉴。更多还原

【Abstract】 As geologic conditions there are quite complicated, construction period is short and there is great construction disturbance, it is hard to select a proper structure to handle permeability and engineering treatment measures are hard to be carried out. To solve the above problems, a systematic study is conducted to develop methods of plugging and obstructing seepage path, combining permeability control theory with site trial test in addition to wide investigation and data collection to confirm the reasonability of the structural mode. The effort ends with high pressure shotcrete and grouting, concrete impervious walls and controllable grout curtain that provide technical support to the selection of impervious structural mode or application of comprehensive solution to permeability of cofferdam foundation. The excavation for dam foundation reveals after the completion of works that the construction quality is good enough to protect against permeability in both upstream and downstream cofferdam foundation, the effect is obvious as the amount of seepage is little at daily rate ranging 200m3～300m3. This sets a solid base for the critical path of high arch dam foundation excavation, timely casting of dam concrete and the milestone target of realizing power generation one year ahead. The effort has achieved significant technical, economic and social benefit, and provided worthwhile experiences in building impervious structure and engineering treatment for deep and complicated cofferdam foundation in southwest region high mountains and deep valleys.更多还原