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一、概述 近年来,环形预应力混凝土电杆纵向裂纹不断出现,已引起有关部门的普遍重视。1980年7月,国家标准总局委托建材部组织铁道、
First, an overview In recent years, the ring longitudinal prestressed concrete pole longitudinal cracks continue to emerge, has aroused widespread attention of relevant departments. In July 1980, the State Administration of Building Materials commissioned the Ministry of Construction Railway,