张力放线施工工艺因素对导线松股的影响及其风险评价

Influence of Tension Stringing Construction Process Factors on Conductor Loose Strands and Its Risk Assessment

导线松股一直是困扰输电线路张力放线施工质量和安全的难题,工程中缺乏有效的定量分析及评价方法。针对上述问题,基于导线过滑车几何关系和有限元理论建立张力放线导线松股仿真计算模型,以JL1/G3A-1250/70-76/7导线为研究对象,从张力放线施工工艺角度考虑导线张力、过滑车包络角、滑车槽底直径、轴向扭矩、导线周向翻转角及过滑车偏斜角等施工工艺因素,设计28组计算工况,结合导线松股变形定量描述指标分析各因素对导线松股的影响。结果表明,滑车槽底直径和导线轴向扭矩为导线松股发生的主要因素,而其余因素会影响松股变形的趋势。在此基础上,采用多项式组合权重建立导线松股风险评价模型,通过2个典型工程案例的导线松股风险计算,验证该模型的有效性。进一步将其应用于新建工程项目导线松股风险预测,得出放线区段松股风险大小以及不同工艺因素对放线松股的影响比重,对有较大松股风险的方案,指出其造成松股的原因和改进的方向。

Conductor loose strand has always been a difficult problem for the quality and safety of tension stringing construction of transmission lines.There is a lack of quantitative analysis and evaluation methods in engineering construction.In view of the above problems,based on the geometric relationship and finite element theory of the conductor passing through the block,a simulation calculation model of the loose strands of conductors in tension stringing is established.Taking the JL1/G3A-1250/70-76/7 conductor as the research object,28 sets of calculation conditions are designed from the perspective of the tension stringing construction process,taking into account the construction process factors such as the conductor tension,the envelope angle of the block,the bottom diameter of the block,the axial torque,the circumferential overturning of the conductor and the block deflection angle.Combined with the quantitative description index of conductor loose strands deformation,the influence of various factors on conductor loose strands is analyzed.The results show that the bottom diameter of the block and the axial torque of the conductor are the main factors for the occurrence of loose strands,while the other factors will lead to an increase in the trend of loose strands deformation.On this basis,the risk evaluation model of conductor loose strands is established by using polynomial combination weight.The effectiveness of the model is verified by the calculation of loose strands risk in two typical engineering cases;It is further applied to the risk prediction of conductor loose strands in new construction projects,and the improvement direction of construction scheme is given,which provides calculation means and reference basis for the risk assessment of conductor loose strands in tension stringing construction and the optimization of construction scheme.