为验证复合浆材堆石体技术思路的可行性,开展了现场试验研究。通过现场浆液制备、分层堆石、注浆及机械碾压,形成复合浆材堆石结构,并进行地质雷达、钻孔取芯检测以及汛后检查,直观评价注浆效果和整体性能。研究结果表明:堆石平均空隙率为26%~30%,注入的浆液流动度为200～240 mm;对于0.5 m和0.75 m层厚的堆石,分别振动碾压6遍和8遍基本满足压实度要求;各注浆碾压层的雷达反射波相对均匀,注净浆的测试结果优于注砂浆;芯样获得率不高,抗压强度8.5~15.1 MPa;实际过流与汛期后检查结果是试验区结构完整、稳定无破坏;为提高施工效率及注浆效果,建议石料去除5 mm以下颗粒并提前湿润,根据现场环境适时调整浆液配方,可采用串筒、溜槽等设备或喷洒方式多点均匀注浆。复合浆材堆石体的技术思路,有助于提高堆石基座的压缩变形模量、减少超高堆石坝的整体沉降,具有广阔的工程应用前景,以期为300 m级超高堆石坝的建设提供技术支撑。

Field exploratory experimental study was carried out to verify the feasibility of the technology of composite slurry-rockfill structure. The test procedures include slurry preparation, layered rockfill, grouting and mechanical rolling. The test methods include geological radar, drilling and coring, and post-flood inspection. Results reveal that the average porosity of rockfill is 26%-30%, and the fluidity of slurry is 200-240 mm. For rockfills with thicknesses of 0.5 m and 0.75 m, vibrating rolling 6 times and 8 times respectively will meet the requirements of compaction. The radar reflection wave of each grouting roller compacted layer is relatively uniform, and the test result of grouting paste is better than that of grouting mortar. The acquisition rate of core sample is not high, and the compressive strength of core sample is 8.5-15.1 MPa. Inspection after the flood season shows that the structure of the test area is complete, stable and undamaged. To improve the construction efficiency and grouting effect, we recommended removing the particles below 5 mm and humidifying in advance and adjust the slurry formula according to the on-site environment. Equipment such as tandem cylinders, chutes, or method of spraying grouting at multiple points can also be employed. The technical idea of composite grout rockfill structure helps to increase the compressive deformation modulus of the rockfill foundation and reduce the overall settlement of the ultra-high rockfill dam, thus providing technical support for the construction of 300 m level ultra-high rockfill dam.