Jining Municipal Bureau of Labor and Social Security. The excavator operation certificate can be handled at the Ministry of Labor or the Safety Supervision Bureau. Jining's excavator operation certificate is handled in Jining Labor and Social Security Bureau, located in Hongxing Middle Road, Shizhong District, Jining City, Shandong Province. Excavators are earth-moving machinery, which use buckets to excavate materials above or below the bearing surface, and load them into transport vehicles or unload them into the stockyard.