降雨作用下裂缝对杆塔基础滑坡影响的物理模型试验

随着全国联网工程的实施，杆塔不可避免地建设在陡坡、山脊、滑坡等地质灾害易发区域，在降雨的影响下，滑坡的变形甚至失稳会直接影响杆塔的安全，从而对电力系统和社会经济的发展造成巨大的影响。本文以燕子滑坡及杆塔基础为研究对象，基于物理模型试验，研究了极端降雨作用下不同相对位置杆塔基础滑坡有裂缝时的失稳过程。首先，设计了杆塔基础滑坡的物理模型试验方案，其次，分析了降雨过程中杆塔基础滑坡的宏观现象以及滑坡体和杆塔基础变形和力学特征的变化过程，最后，总结了降雨作用下杆塔基础滑坡成灾模式的分析流程。结果表明，降雨作用下，预制裂缝为雨水提供了优势渗流通道，使得预制裂缝深度、宽度逐渐扩大，并向滑坡右端逐渐延伸并贯通，导致右端坡脚局部发生失稳而形成多级局部牵引滑动破坏；滑坡上的杆塔基础和滑坡外的上部杆塔都随着滑坡一起向下滑移并发生向后倾倒，后者发生的时间晚于前者，但滑坡外的底部杆塔基础在整个过程中没有发生破坏。此外，降雨作用下燕子杆塔基础滑坡有裂缝时应以局部滑坡的变形和稳定性来分析杆塔基础的成灾模式。本文的研究成果可为杆塔基础滑坡实际工程提供一个直观上的认识和技术上的支撑。

Physical Model Test on the Influence of Crack on Tower Foundation Landslide Under Rainfall

With the implementation of national networking projects, power transmission towers will inevitably be built in areas prone to geological disasters such as steep slopes, ridges, and landslides. Under the influence of rainfall, the deformation and even instability of the landslide will directly affect the safety of the towers, which will have a huge impact on the development of the power system and social economy. This article takes the Yanzi landslide and the tower foundation as the research object. Based on the physical model test, the instability process of the tower foundation landslide with cracks in different relative positions under rainfall is studied Firstly, a physical model test plan for the tower foundation landslide is designed. Then, the macroscopic phenomenon of the tower foundation landslide and the change process of the deformation and mechanical characteristics of the landslide and the tower foundation during the rainfall process are analyzed. Finally, the analysis process of the disaster model of the tower foundation landslide under rainfall is summarized. The results show that prefabricated cracks provide advantageous seepage paths for rainwater, and rainfall gradually expanded the depth and width of the prefabricated cracks, and gradually extended and penetrated to the right end of the landslide, causing local instability of the toe at the right end of the landslide and resulting in multi-level local traction and sliding failure. The tower foundation on the landslide and the upper tower foundation outside the landslide both slide down along with the landslide and fall backwards, and the latter occurred later than the former. But the bottom tower foundation outside the landslide dose not damage during the whole process. Further, when there are cracks in the Yanzi landslide, the deformation and stability of the local landslide should be used to analyze the disaster mode of the tower foundation under rainfall. The research results of this paper can provide an intuitive understanding and technical support for the actual project of the tower foundation landslide.