摘要
西藏高海拔地区建筑物雷击灾害严重,为弄清其防雷接地环境,探索出合适的防雷接地降阻措施,从建筑场地取回岩石样本,利用岩石取芯机钻取圆柱岩样,在岩样两端面用导电胶外粘金属电极片,在直流伏安电阻测试系统中采用二极法测试不同环境温度下岩石的电阻率,分析岩性和环境温度对岩石电阻率的影响.结果表明:受成岩矿物的影响,相同条件下,花岗岩电阻率高于砂岩电阻率;岩石电阻率随温度降低而升高,正温对岩石电阻率影响较小,而负温对岩石电阻率影响较大,-30℃时花岗岩的电阻率比10℃时的电阻率大11倍.总的来说,对于以花岗岩为主要岩石类型、雷击发生于冬季且集中于夜里的高海拔地区建筑物,其防雷接地环境是十分恶劣的.
Abstract
Lightning disaster of buildings is serious in the high altitude area of Tibet.In order to clarify its grounding environment and explore suitable lightning protection and grounding resistance reduction measures,rock samples were taken from the construction site and cylindrical rock samples were taken by rock drilling machine.Then metal electrodes were bonded to the samples' ends surface with conductive glue.Resistivity of rock under different ambient temperature was tested in the DC voltammetry resistance test system using two-pole method.The results showed that:resistivity of granite is great than that of sandstone due to the influence of composition minerals.Rock resistivity will increase with temperature decreasing and influence of positive temperature on rock resistivity is slight while that of negative temperature on rock resistivity is critical.Granite resistivity under-30℃ is 11 times larger than that under 10℃.In general,for the granite rock types,lightning strikes occur in the winter and mainly in the night,grounding environment of the high altitude buildings is very poor.
NETL
NSTL
维普
万方数据