深圳地区输电线路边坡病害类型分析

Analysis of Hidden Danger and Disease Types of Transmission Line Slopes in Shenzhen

深圳地区降雨充沛,地质条件脆弱,在丘陵山地密集建设的输电网沿线存在大量边坡隐患及病害,本文基于深圳地区500kV鹏深甲乙线和220kV丽腾甲乙线共120处隐患杆塔边坡的调查分析,将输电线路边坡隐患及病害分类划分为基本稳定(含填方边坡和挖方边坡2个子类)、坡体病害(含坡表水土流失、坡体局部崩塌、边坡整体滑动、库岸边坡冲刷4个子类)和结构缺损病害(含排水不畅、支护破损、塔腿临空3个子类)共3大类9亚类;并得出强降雨条件下深厚的岩土风化壳及边坡开挖弃土是坡表水土流失、坡体局部坍塌及边坡整体滑动等边坡病害的主要原因,人类工程活动和库岸边坡冲刷加剧了该类边坡病害的发生概率;输电杆塔边坡周边截排水沟堵塞或防护结构劣化是常见的边坡防护结构缺损病害,杆塔基础设计或施工中未预留足够的安全距离,造成塔腿临空需要重点监测或开展必要的处治。

With abundant rainfall and fragile geologic conditions in Shenzhen area, there are a large number of hidden slope hazards and diseases along the densely built transmission lines in hilly and mountainous areas. This paper is based on the investigation and analysis of 120 tower slopes with hidden diseases about Shenzhen 500 kV Pengshen– A - B line and 220 kV Liteng - A - B line. The classifications of hidden danger and disease in transmission line slope are classified as basically stable (2 sub classes including fill slope and cut slope), slope disease (4 sub classes including soil erosion with slope's surface, local collapse of slope body, overall sliding of slopes, the scouring of bank slope) and structural defects (3 sub classes including poor drainage, support breakage, lack protect of tower leg), which in total are 3 categories and 9 subclasses. It is pointed out that the deep soil weathering crust and slope excavation and abandonment are the main causes of slope diseases such as soil erosion, partial collapse of slopes and overall sliding of slopes. Human engineering activities and bank slope erosion aggravate the occurrence probability of this kind of slope disease. It is a common disease of structure defect of slope protection that the surrounding section drains of the transmission tower slope are blocked or the protective structure deteriorate. The Tower foundation design or construction has not reserved enough safe distance, which result in the need to focus on the tower leg to monitor or carry out the necessary treatment.