The existing 400 mm concrete pipe of 30 mm wall thickness was laid on a solid slump concrete base of 700 mm width and 150 mm thickness at the invert with steel reinforced concrete caps at each pipe joint, every two metres apart.
The main ranged in depth from 1.5 m to 3.5 m, and went through no less than ten manholes and had seven direction changes. The project was made even more challenging by the fact that the main ran through a narrow street between the Beijing Union University and local residential high rise units.
The Chuanganya Trenchless Technology and Engineering company researched pipe bursting equipment manufacturers in great detail worldwide, evaluating cost of equipment, equipment specifications, performance/history/job reports of equipment, technical support and after sales service.
After completing a rigorous and comprehensive study of the equipment available, and evaluating the suppliers, the company chose the TT Group’s 80 tonne pull back machine.
The 800 G stood out from the competition for many reasons, but the main virtues that made the decision easier were:
“¢ Quality of the equipment;
“¢ The patented interlocking “÷QuickLock’ Rods that enable quick and efficient operation;
“¢ The ability of the machine to pull the expander and new pipe into the extended frame of the machine; and,
“¢ Technical support and after sales service.
The original sewer main was laid in 1982 and in recent years had shown signs of serious gas corrosion, requiring two major repairs in the 3 to 3.5 m depth sections. It was decided that the capacity of the main had to be maintained or preferably improved. It was then decided that the new replacement would be a 450 mm SDR 21 PE 80 Polyethelyne pipe.
In July, with field engineers from TT Asia Pacific and Local TT Distributor McAllen (Tianjin) on site, the project started, commencing from manhole one through to manhole ten with the longest section of 84 metres and an 8 degree bend at manhole two.
The project was completed well within the capabilities of the Grundoburst 800 G machine, proving itself to be an excellent investment for the future for the company.
Wang Guohui, Managing Director of The Beijing Chuanganya Trenchless Technology and Engineering Co and his General Manager, Bai Xiaohong chose to be trained in using the 800 G on a very challenging project. In doing so they also introduced the first large capacity hydraulic pipe bursting machine into China and they were most pleased with the performance of the TTG equipment and the training and support from TT Asia Pacific.