渗流诱发红土滑坡的防渗新模式探索

These landslides have a consanguineous connection with deviant seepage, such as tailing dam， riverside and dyke. Seepage not only dissolves and schleps out viscous substances and small granules in soil，so brae would be relaxed and lose its stabilization, bat Seepage also has bad actions of buoyancy, lubricating and water thrust. According as principia of effect a permanent cure at such landslides, momentous problems will be solved in anti-seepage system. Landslides brought by deviant seepage often occurred in Yunnan coteau of China, and benefits of prevention and cure were prevalent low at such landslides. Destroying mechanism of conventional anti-leakage bodies was studied, a lot of paper were published, and patent rights were confirmed about optical fiber geomembrane. Ground on prophase analysis and tests, new ideas of united anti-leakage were put forward. Conventional anti-leakage bodies will combine with optical fiber geomembrane, to make united anti-leakage system possessing multi-materials and monitor. For the united anti-leakage, combined modes and structure stability will be researched, the appetency of anti-leakage materials and laterite will be tested, and earthquake damage along with boundary seepage will be analyzed. So basal data of united anti-leakage system will be obtained for actual purpose. Groping for new anti-seepage mode would have a pervasive significance for anti-leakage and anti-slide of groundwork and slope in laterite. Problems would be solved such as eroding chronically to materials, impotent stakeouts, landslide brought by deviant seepage. A new route would be found for prevention and cure of landslides. Furthermore, valuable data could be offered for non-laterite slopes.

在尾矿坝、河岸、堤坝等斜坡上出现的滑坡，与异常渗流密切相关。渗透不仅溶蚀带走了岩土中的胶体物质和细颗粒、致其酥松失稳，还具有浮托、润滑、推动等负面效果。考虑到这类滑坡的治本原则，本项目侧重于解决红土防渗体系的重大缺陷。 渗流诱发的红土滑坡在云南山区经常发生，这种滑坡的防治效益普遍很低。前期工作明晰了红土斜坡中防渗体的破坏机制，发表了较多论文并获得光纤土工膜的发明专利权。本项目将传统防渗体与光纤土工膜相结合，构成多材料、可监测的联合防渗模式。对这种新体系的构造型式及其稳定性、层次厚度、耐久性、监测阈值，防渗体与红土斜坡的亲和性、联合抗震，以及边界渗流规律等等内容进行研究，以期取得必要的基础性成果。 本项目的探索对于红土类地基及边坡的防渗抗滑具有重要意义，能够解决传统防渗体劣化太快、监测成效太低、渗流诱发滑坡等难题，将为红土涉水型滑坡的防治开辟新思路，并为其它类型岩土中的防渗研究提供参考资料。

岩土体内部的较高水位将产生压力渗流，随之而来的溶蚀、浮托、润滑、推动等作用显著降低了边坡的稳定性，在地层、材质、坡度、温度等其它条件相同的情况下，异常渗流的斜坡发生滑塌的风险大得多。依据“疏堵结合”的治理原则，本项目侧重于“堵”的应用基础研究，针对多地震红土覆盖区域探索解决传统防渗体系的重大缺陷，主要包括对水土及其生物侵蚀的抵抗力弱、对地震和变形的适应性差、抗渗效率较低、内部破损后无法及时定位等长期未能解决的难题。.以光纤土工膜为主要材料，采用理论分析、现场勘测、分项检测、数值模拟、模型试验等多种手段，研究多材料、可监测的新型防渗体。探讨防护层、抗渗监测层、包裹层、传载体之间的界面结合机制，确定了有利于延长防渗体寿命的各层次材料及其组合模式。分析各种材料之间的物理和化学作用，依据对主体工程扰动最低、界面抗震稳定性最好的原则，优化新型防渗体的表面与形体结构，明晰柔韧抗渗层的应力调整优势，按照不同工程的要求试验确定了传载体和垫层的相关设计。研究在防渗体中密集监测和破损定位的措施，依据测试数据设定测点间距，拟定告警阈值和现场标定方法，提出了及时有效的渗流监测和破损定位方案。在技术经济分析的基础上，针对不同红土工程提出了4种防渗体的层次结构以及设计、施工方案。.新型防渗体采用光纤土工膜、芳纶布和很薄的传载体组成，具有高效率防渗、密集监测、均衡应力、适应变形等诸多优势，能够抵御酸碱侵蚀和动植物的长期破坏，对地震、不均匀沉降，传载体断裂等均具有较好的适应能力，并能及时而准确地测定其破损位置。高效而长寿的防渗体不仅有利于阻止边坡滑塌，而且对于压力渗流导致断层地震的防范也有较好效果，故对于渗流诱发红土类滑坡的防治具有普遍适用意义，在地质灾害防治、岩土工程防渗加固领域具有较高的推广价值。