斜坡地形输电线路桩基础设计研究

Research on Pile Foundation Design of Transmission Line in Slope Terrain

摘要:

针对山区输电线路桩基础，利用有限差分软件FLAC3D研究斜坡地基情况下桩基础承载力与地形坡度、地质岩性、设计虚坡宽度等因素的关系。数值分析结果表明地形坡度越大、地质岩性越差、虚坡宽度越小时，斜坡地基承载力安全系数越小。通过对某±800kV特高压直流工程典型直线塔和耐张塔的算例计算分析，给出了输电线路典型岩石地基的等效m值取值建议。并通过引入m值折减系数μ，考虑了地形坡度和不同耐张塔转角度数对桩基础水平承载力的不利影响，供广大同行参考。

Abstract:

Aiming at the pile foundation of transmission lines in mountainous area, the relationship between the bearing capacity of pile foundation and the factors of topographic slope, geology and lithology, width of design virtual slope in slope terrain are studied by using FLAC3D. Numerical analysis results indicate that, the larger the topographic slope, the worse the geological lithology and the smaller the width of virtual slope, the smaller the safety factor of the bearing capacity of slope foundation. Through the example analysis of typical suspension towers and tension towers of a ±800 kV UHVDC project, the equivalent m value of typical rock foundation is proposed. With the introduction of reduction factor μ for m value method, the adverse effects of topographic slope and different angle of tension tower on the horizontal bearing capacity of pile foundation are also considered, which is provided to designers for reference.