摘要
随着煤矿采空区的扩大和西部冻胀区输电塔数量的增加,非均匀沉降对输电塔的影响研究显得越来越重要.目前,输电塔的设计和研究大多忽略螺栓滑移的影响.本研究建立了一个模型塔,选取塔中典型的螺栓接头,通过实验得出接头的力-位移关系曲线,并用非线性弹簧将其引入到有限元分析中.分别建立了含滑移和不含滑移两种输电塔模型,利用有限元软件ANSYS探讨了滑移对承受非均匀沉降输电塔的承载能力的影响.分析表明,无沉降时,两种模型得出的承载能力相差不大;有沉降时,不考虑滑移的模型塔承载能力随沉降量的增加而大幅下降,而考虑滑移模型塔的承载能力下降相对较缓慢.考察杆件受力,发生沉降后,螺栓滑移使塔腿产生附加内力,而各层斜撑杆的内力则趋于均匀.本研究结论对于实际承受非均匀沉降输电塔的承载能力评估具有指导意义.
With the old coal mining area expanding and the number of transmission towers increasing in the frost heaving areas of western China, the influence of the base unequal settlement on the transmission tower is becoming increasingly significant. At present, bolt slippage is ignored in almost all the design or research of transmission towers. In this research, a model transmission tower was set up and two typical bolt connection joints of the tower were selected for the experiment to obtain their load-displacement （L-D） relationships, which were further adopted in the finite element analysis through a nonlinear spring model. Based on ANSYS software, a numerical analysis was performed to observe the effect of bolt slippage on the transmission tower with base unequal settlement. It was found that, without base unequal settlement, bolt slippage has little effect on the bearing capacity of the transmission tower. As the base unequal settlement increases, the bearing capacity of the transmission tower decreases quickly in the non-bolt-slippage model, while it decreases slowly in the bolt-slippage model. After the base unequal settlement occurs, additional forces of the tower legs appear and the axial forces of the diagonal bracings in different layers become uniform owing to bolt slippage. The results are significant to the accessment of the bearing capacity of transmission towers with
