多种采动影响区杆塔地基稳定性数值分析

NUMERICAL ANALYSIS OF TRANSMISSION TOWER FOUNDATION STABILITY AT VARIOUS ZONES AFFECTED BY COAL SEAM MINING

煤炭开采中多种采动影响区包括老采空区、现采空区和未来采空区(规划区)等几种类型。本文对晋东南至南阳段1000kV特高压输电线路途经山西煤田采空区和规划区,评价规划区煤层开采对已建输电杆塔地基稳定性的影响,根据现场收集的资料,利用FLAC3D数值方法对特高压线路N177输电杆塔下部3号煤层进行开采模拟,并在3号煤层已经开采条件下,进行9号煤层复采的数值模拟。结果表明,9号煤层复采将对输电杆塔地基稳定性造成影响,地表最大沉降为1.15m,输电杆塔基础沿线最大倾斜为5.7‰,开采过程中如杆塔基础不采取抗变形措施,杆塔基础倾斜将会危及到特高压输电线路的稳定。

Coal mining has caused a variety of mining-affected zones including old mined-area,present mined-area and future mined-area.The 1000 kV UHV transmission line of Southeast Shanxi to Nanyang passes through the mined out space and layout area of Shanxi coalfield.This paper appraises the influence of mining of coalfield layout area to the foundation stability of the transmission towers.Based on the locally collected data,it used the FLAC3D numerical method.The mining simulation of the coal seam 3# under the N177 tower of the 1000 kV UHV transmission line is presented.After the coal seam 3# has been conducted,the numerical simulation of coal seam 9# is established.The results are as follows： The mining of the coal seam 9# can bring influence on the stability of the transmission tower foundation.The most subsidence of the ground is 1.15m and the most inclination of the transmission tower foundation along the power line is 5.7‰.Without taking anti-deformation measures,the inclination of the tower foundation will endanger the stability of 1000 kV UHV transmission line.