小口径钢管桩修复加固拦砂坝坝基土的技术方法研究
Research of Small Caliber Steel Pipe Piles to Reinforce the Foundation of Check Dam and Preventit from Scouring by Debris Flow
作者：石胜伟(中国地质科学院 探矿工艺研究所, 四川 成都 611734;中国地质调查局 地质灾害防治技术中心, 四川 成都 611734)；刘建康(中国地质科学院 探矿工艺研究所, 四川 成都 611734;中国地质调查局 地质灾害防治技术中心, 四川 成都 611734)；蔡强(中国地质科学院 探矿工艺研究所, 四川 成都 611734;中国地质调查局 地质灾害防治技术中心, 四川 成都 611734)；周路旭(中国地质科学院 探矿工艺研究所, 四川 成都 611734;中国地质大学（北京）, 北京 100083)
Author：SHI Shengwei(Inst. of Exploration Technol., Chinese Academy of Geological Sciences, Chengdu 611734, China;Technical Center for Geological Hazard Prevention and Control, China Geological Survey, Chengdu 611734, China)；LIU Jiankang(Inst. of Exploration Technol., Chinese Academy of Geological Sciences, Chengdu 611734, China;Technical Center for Geological Hazard Prevention and Control, China Geological Survey, Chengdu 611734, China)；CAI Qiang(Inst. of Exploration Technol., Chinese Academy of Geological Sciences, Chengdu 611734, China;Technical Center for Geological Hazard Prevention and Control, China Geological Survey, Chengdu 611734, China)；ZHOU Luxu(Inst. of Exploration Technol., Chinese Academy of Geological Sciences, Chengdu 611734, China;China Univ. of Geosciences(Beijing), Beijing 100083, China)
收稿日期：2018-08-03 年卷（期）页码：2019,51(5):33-40
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：泥石流;拦砂坝;坝下冲刷;小口径钢管桩;修复加固
Key words：debris flow;check dam;scouring below dam;small caliber steel pipe piles;reinforcement
基金项目：国土资源部公益性行业专项（201511051）；国家自然科学基金项目（41402315）；中国地质调查局项目（DD20160279；DD20190644；20190505）
中文摘要
坝下冲刷是拦砂坝满库后存在的主要隐患问题之一，在泥石流巨石冲击和流体冲刷作用下，以护坦、副坝、潜坝为主的常用坝下防冲消能措施逐渐损毁失效，所形成冲刷坑的溯源侵蚀作用诱发坝基悬空，极易导致拦砂坝主体失稳倾覆或冲毁失效。为解决这个难题，延长拦砂坝服役期限，提高工程经济效益，提出了一种小口径钢管桩修复加固泥石流拦砂坝坝基土的技术方法，其主要作用原理是在拦砂坝坝趾至集中冲刷区段范围以内的松散层埋设小口径钢管桩，并利用桩身孔眼注入水泥浆进行渗透扩散，将桩间松散层和钢管桩结合形成固结体，达到同时减少越坝泥石流直接冲击冲刷破坏和提高坝基土抗冲能力的目的，以防止泥石流的溯源侵蚀破坏，确保拦砂坝主体结构的安全运行。通过理论分析和简易模型试验手段，介绍了技术方法中小口径钢管桩埋设位置、埋设深度、埋设间距和埋设排列4项关键参数的设计原理和计算依据；通过实施绵竹市清平镇雍家沟泥石流工程案例示范，验证了修复加固技术的良好效果，为泥石流拦砂坝坝下冲刷缺陷问题的修复加固方案提供了技术参考。
英文摘要
Scouring below the check dam is a doomed consequence after the upstream reservoir is fully deposited by debris. With the boulders crashing and debris flow scouring, apron, auxiliary dam or submerged dike which is commonly used as an erosion-control below the dam is gradually damaged. In the meantime, a scoured pit is formed and expanded, causing exacerbated headward erosion to the foundation of the dam, and easily inducing a toppling failure to the dam. In order to solve this problem, this paper puts forward an application of small caliber steel pipe piles to reinforce the foundation of check dam and prevent it from scouring by debris flow. The principle is that the small caliber steel pipe piles are embedded in the debris deposit at the front side of the dam toe, and the cement slurry is also injected into the pipe piles, to penetrate into the loose debris between the piles and bond the pipe piles and the debris deposit together. Through these steps, a consolidation body with a stronger anti-scour ability is formed, preventing the dam foundation from the headward erosion by debris flow and ensuring its safe running. By means of theoretical analysis and laboratory test, 4 key parameters of embedding location, pile depth, spacing between piles and layout arrangement are determined for the technical method design. Finally, an engineering project is carried out in the Yongjiagou debris flow valley in Mianzhu City, validating that this technical method has a good reinforcing effect. It is hoped that this will provide a reference for the erosion-control design for check dams in the future or for the rehabilitation and reinforcement in the maintenance stage.
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