小南海水库地震堆积坝体生产性试验灌浆研究

通过生产性试验灌浆研究,进一步证明地震堆积坝体具有良好的可灌性,帷幕灌浆能够解决坝体的渗漏问题.采用硬质合金或金刚石钻头泥浆护壁、分段回转钻进的钻孔方法和孔口封闭、自上而下分段、孔内循环式的灌浆方法,灌注水泥粘土浆液,适当提高中排孔的灌浆压力,对堆积坝体进行帷幕灌浆在技术上是可行的;采用三排帷幕,按渗漏分布现状进行灌浆孔的布置,最大孔距3.5m,深入基岩1.0m,可以形成完整、连续、可靠的防渗幕体,满足坝体防渗要求;采用潜孔偏心锤跟管钻进、多级孔径套管护壁钻进等施工工艺,可以解决检查孔的钻进问题;采用静水头压水试验,测试成果可以真实地反映地层的透水特性.从试验灌浆资料和质量检查分析,试验灌浆效果明显,达到了指导帷幕灌浆设计和施工的目的.

Study on experimental grouting to earthquake accumulative dam in Xiaonanhai reservoir

By study on the productive grouting experiment, earthquake accumulative dam was of very good groutablity was testified, the problem of dam leakage can be solved by curtain grouting. Adopting the carbide alloy or diamond aiguille slurry breast wall, piecewise gyration drilling method, orifice close, section division from top to bottom, cyclic hole injection method, it was proved feasible to pour cement clay slurry, increase the hole grouting pressure and carry out a grouting curtain onto the accumulative dam. Adopting three rows of curtain, distributing the injection holes according to the current situation of leakage positions, with 3.5 meter pitch-row and 1.0 meter-depth into the bedrock, entire, continuous and reliable impervious curtain could be formed, and meet the requirement of seepage prevention. Adopting the techniques of latent hole partiality hammer and pipe-along drilling, multi-level aperture casing pipe drilling, the problem of inspection hole drilling was solved. The inspection hole sections were subjected to pressurized-water test, which truly reflected the stratum permeable characteristic. From injection test data and the quality inspection analysis, it was obvious that injection had fulfilled the purpose of guiding curtain grouting design and construction.