基于放顶煤开采地表移动预计的输电铁塔安全性研究

Safety Study on Transmission Tower Based on Prediction of Surface Movement of Coal Caving Mining

为了评价五间房规划区煤层开采对输电铁塔安全性的影响,通过FLAC3D数值模拟及优化求参的概率积分法模型预计地表移动,基于综合预计结果,利用ANSYS研究放顶煤开采引起的地表复合变形作用下输电铁塔内力和变形特征,并从铁塔结构和横担倾斜方面评估了其安全性。结果表明:2种方法预计结果吻合较好,综合预计结果可靠,地表沉降最大值为1.86 m,东西向最大水平移动为524 mm,南北向最大水平移动为737.5 mm。铁塔最大轴向拉应力为25.2MPa,尚未超过Q235角钢拉杆许用应力,铁塔自身结构尚未破坏。铁塔横担倾斜度高达29.5‰,其值超过了铁塔的倾斜度允许值不超过10‰的限定,建议开采过程采取相应措施控制地表移动,并加强对铁塔变形的监测,以确保输电铁塔的安全运行。

To evaluate the influence of mining of Wujianfang coal field layout area on the safety of transmission tower,the surface movement was predicted by FLAC3Dnumerical simulation and the optimized probability-integration method to obtain parameters.Based on comprehensive forecast results,ANSYS was used to study characteristics of the internal force and deformation of the transmission tower based on the composite surface deformation of caving mining,and evaluated its safety in terms of its structure and slope of cross-arm.Results show that,the surface movement predicted by the above two methods are close together and the comprehensive forecast results are reliable.The most subsidence of the ground is 1.86 m.The most horizontal movement is 524 mm from east to west.The most horizontal movement is 737.5 mm from north to south.The most axial tensile stress of the tower is 25.2 MPa,which does not exceed the allowable stress of Q235 steel.The structure of the tower is in a safe state.The incline of the cross-arm of the tower is as high as 29.5‰,and its value exceeds the limit of 10‰.Taking measures to control the surface movement and strengthen the monitoring of the deformation in mining process can ensure the safe operation of the transmission tower.