山区输电线路基础设计与岩石地基勘察研究

Foundation Design and Rock Subgrade Survey for Transmission Lines in Mountain Areas

摘要: 由于输电线路行业的特殊性和山区地形地貌地质环境及交通运输条件的复杂性，山区杆塔基础选型设计与岩石地基勘测一直是我国电网工程建设的难点。本文根据山区覆盖土层厚度的不同，将山区输电线路挖孔基础分为岩石嵌固基础和嵌岩桩基础2种型式，进一步分析了山区输电线路岩石锚杆基础、岩石嵌固基础和嵌岩桩基础的结构型式、适用条件、承载力计算模型及其地基设计参数。结果表明，岩石单轴抗压强度是岩石锚杆基础、岩石嵌固基础和嵌岩桩基础设计的关键地质参数。根据山区输电线路地基勘察特点，推荐了利用点荷载试验确定岩石单轴抗压强度的方法，并给出了基于点荷载试验的山区输电线路杆塔基础设计参数取值计算方法，研究成果可为山区输电线路杆塔基础工程设计提供借鉴。

Abstract: Due to the particularity of transmission line industry and the complexity of mountainous terrain, geomorphology, geology and transportation conditions, the tower foundation selection and design in mountainous areas and the rock subgrade survey have become the difficulty for power grid construction in China. According to the thickness of overburden soil in mountainous area, the ex-cavated rock foundation of transmission line in mountainous area was divided into rock-embedded foundation and rock-socketed pile foundation. The structural model, applicable conditions, bearing capacity calculation model and foundation design parameters of rock anchor bolt, rock-socketed foundation and rock-socketed pile foundation of transmission line in mountainous area were suggested. The results indicated that the uniaxial compressive strength of rock is the key geological parameter for the design of rock bolt, rock-embedded foundation and rock-socketed pile foundation in mountainous area. Therefore, the point load test method was recommended to determine the uniaxial compressive strength of rock mass. Furthermore, the method of selecting design parameters for transmission line tower foundation in mountainous area which are based on the results of point load test was also given. The research results can provide data for the design of transmission line tower foundation in mountainous area.