真空联合堆载预压法在寒区筑坝工程中的应用  

Application of vacuum combined surcharge preloading method in dam construction in cold regions

作　　者：占鑫杰[1] 杨守华[1] 朱群峰[1] 米占宽[1] 赵士文 于仲离 滕昊 ZHAN Xinjie;YANG Shouhua;ZHU Qunfeng;MI Zhankuan;ZHAO Shiwen;YU Zhongli;TENG Hao(Nanjing Hydraulic Research Institute,Nanjing 210029,China;NHRI R&D Tech Group Co.,Ltd.,Nanjing 210029,China;Foundation Engineering Branch of China Water Conservancy and Hydropower First Engineering Bureau Co.,Ltd.,Dalian 116041,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]南京水科院瑞迪科技集团有限公司,江苏南京210029 [3]中国水利水电第一工程局有限公司基础工程分局,辽宁大连116041

出　　处：《水利水运工程学报》2023年第6期168-175,共8页Hydro-Science and Engineering

基　　金：江苏省水利科技项目(2020-07);中央级公益性科研院所基本科研业务费重点项目(Y323002)。

摘　　要：真空联合堆载预压法是中国沿海地区常用的软基处理方法,但在北方地区筑坝工程中缺少工程案例和施工经验,具体表现在传统的插板工艺、密封墙工艺对复杂地层适应性不明确,大体积坝体堆载后密封膜的密封效果未知,冬季低温冻结力会破坏饱水的密封和排水系统。为此依托中国北方某土坝工程,选取先导试验段,分别开展塑料排水板插板工艺试验、密封墙成墙试验、密封膜保护试验和坝基防冻试验。研究结果表明:履带式振动插板工艺能有效穿透上覆硬壳层,其施工效率优于引孔+振动插板工艺;采用1.2 m双排泥浆搅拌墙方案能起到良好的负压密封效果;在密封膜表面铺设无纺布、编织布,过渡层采用轻型压实能有效保护真空密封膜。在土坝上层和坡脚填筑2 m的防冻层,可有效防止地基土层和排水系统冻结,冬歇期后真空排水系统可正常运行。Vacuum combined surcharge preloading method is a commonly used foundation treatment method in coastal areas of China.However,there is a lack of engineering cases and construction experience in dam construction projects in the northern regions.Specifically,the adaptability of the conventional PVD installation process and sealing wall process to complex stratum is not clear,the sealing effect of the sealing membrane after large volume dam loading is unknown,and in winter the freezing force may damage the saturated sealing and drainage system.For this purpose,based on an earth dam project in northern China,a pilot test section was selected and installation test of prefabricated vertical drains,formation test of the sealing wall,protection test of sealing membrane and anti-freezing test of the dam foundation were carried out.The test results show that the crawler type vibratory installation process can effectively penetrate the overlying hard soil layer,and its construction efficiency is better than“pilot hole+vibratory installation process”.The 1.2 m double-row mud mixing wall can play a good sealing effect.Non-woven cloth and woven cloth are laid on the surface of the sealing membrane,and the lightly compacted transition layer can effectively protect the sealing membrane.A 2 m anti-freezing layer on the upper layer and the foot of the earth dam can effectively protect the foundation soil layer and drainage system from freezing,and the drainage system can operate normally after the winter period.

关 键 词：寒区 筑坝工程 真空联合堆载预压 软土地基 

分 类 号：TV223.5[水利工程—水工结构工程]