以某塌陷区上典型输电铁塔为背景,采用数值分析方法,分析了动态地表变形(水平变形和竖向变形)对输电铁塔结构附加内力和变形的影响规律.结果表明,输电铁塔在从盆地边部到中部的过程中,首先经历正曲率与拉伸作用,经过拐点后,又经历负曲率与压缩作用;输电铁塔底部杆件的轴力变化较上部杆件变化幅度大,随着高度增加,其轴力变化值越来越小;下部杆件主要受地表水平变形(拉伸、压缩)的影响,而上部杆件受竖向变形(倾斜)影响较大;输电铁塔支座的最大垂直位移差值出现在盆地中部与边部之间的1/2处,支座最大水平位移差值出现在盆地中部与边部之间的1/4与3/4处.
A typical transmission tower in a subsidence area was numerically analyzed. The influence of dynamic ground deformation (horizontal and vertical deformation) on the additional internal forces and structural deformation of the transmission tower was studied. The results indicate that,during its movement from the edge to the center of the basin,the transmission tower experiences two processes divided by a inflection point. One is positive curvature and extension deformation. The other is negative curvature and compression deformation. The axial forces of bars at the bottom of the transmission tower have larger variation than those of the upper bars of the tower. With the increase of altitude,the variation of the axial forces of the bars decreases. The lower bars are mainly influenced by horizontal deformations (tension and compression deformations) of the ground surface,and the upper ones are dominated by vertical deformations (declining deformation). The maximum vertical displacement difference of the supports of the transmission tower appears at the midpoint between the center and the edge of the basin,and the maximum horizontal displacement difference of the supports appears at points one fourth and three fourths the distance between the center and the edge of the basin.