Yunnan Tianyu Blasting Technology Co., Ltd. is a professional blasting design and construction team approved by the Yunnan Provincial Public Security Department, and is also a blasting company in Yunnan Province holding a Class I (Grade A) qualification. To improve the mechanization level and production efficiency of blasting operations, the company introduced an Atlas Copco PowerROC D55 down-the-hole hydraulic surface drilling rig (hereinafter referred to as the "PowerROC D55 drilling rig") in February 2013 and successfully applied it to the Baishadi earthwork leveling project in Kunming City, Yunnan Province. This is also the first "towns built on hills" project in Kunming City, Yunnan Province, and is of vital significance to the urban planning and construction of Kunming.

　　Towns Built on Hills Face Numerous Difficulties

　　According to Zhang Jiayun, manager of the Safety and Equipment Department of Yunnan Tianyu Blasting Technology Co., Ltd., the company undertook the site leveling and blasting task at Baishadi. The project is located in Majie Subdistrict Office, Xishan District, Kunming City, with an average altitude of 2,500 meters, rock hardness of F=10, and a total rock blasting volume of 3.5-4 million cubic meters. The site currently has four blasting drilling rigs, including three pneumatic split drilling rigs and one PowerROC D55 drilling rig. There are mainly two difficulties in construction: first, the rock layer at the site contains sand and soil, making rod jamming and bit sticking prone to occur; second, Kunming has had relatively high precipitation this year, with the total precipitation by July 2013 about 50% higher than the total for the whole of last year. Because rainwater enters the holes, it has brought many difficulties to the rock blasting work. In addition, the mountain terrain here is steep and there is almost no working platform, which also places higher demands on the climbing ability of the drilling rig.

　　PowerROC D55 Proves Its Might

　　Under such circumstances, Yunnan Tianyu Blasting Technology Co., Ltd. decisively introduced an Atlas Copco PowerROC D55 drilling rig and achieved good application results. When talking about the original intention behind choosing this equipment, Manager Zhang Jiayun said: "The Atlas Copco PowerROC D55 drilling rig has stable performance, high production efficiency, simple operation, and is safe and environmentally friendly. It fully meets all our requirements for a drilling rig, and its excellent climbing ability has also helped us solve many difficulties in construction."