地质活动对长距离高落差GIS/GIL形变特性的影响规律OA

In topographically complex regions characterized by high altitude and large elevation difference,such geological activities as geothermal effects,geological subsidence,and earthquakes can substantially complicate the deformation and stress characteristics of gas-insulated metal-enclosed switchgear(GIS)and gas-insulated transmis-sion line(GIL)and,in severe cases,induce cracking or plastic deformation,thereby threatening the safe operation of gas-insulated transmission systems.In this paper,a 550 kV GIL is taken as a case study,the basic units compris-ing horizontal sections,vertical shaft sections,inclined shaft sections,and elbow sections are constructed,and an in-tegrated long-distance,high-elevation difference pipeline model is established with a vertical elevation difference of 100 m,an east-west span of 40 m,and a north-south span of 20 m.The three categories of geological activity are re-spectively equivalent to thermal loads,forced-deformation loads applied at pipeline-soil contact points and multi di-rectional inertial acceleration loads.The nodal deformations are then obtained through static solutions under multi-ple operating conditions.The results indicate that under geothermal action the axial deformation of straight sections increases approximately linearly with temperature,reaching a maximum of 70 mm at 65℃,while the top of the in-clined shaft section exhibits overstress beyond 40 ℃.Under geological subsidence,the axial deformation of horizon-tal sections remains essentially unchanged whereas the vertical deformation increases with subsidence,and the inte-grated model exhibits an abrupt deformation transition as subsidence increases from 15 mm to 16 mm.Under seis-mic action,the maximum deformation of vertical sections reaches 12.77 mm,far exceeding the 0.2 mm observed in horizontal sections,and the elbow structures demonstrate a pronounced effect in vibration mitigation and load distri-bution.On this basis,the optimal installation position of the bellow is investigated using the entropy weight method.The results indicate that arranging the bellow in the middle horizontal section yields better improvement under high-temperature conditions.This study reveals the differences in the deformation response patterns of GIS/GIL under various geological activities,which can provide a reference for structural design and operational safety assessment of GIS/GIL in complex terrain conditions.