At the pile foundation construction site of the 178-meter super high-rise project in Building 7 of Shenzhen China Resources City Phase III, six Sany rotary drilling rigs are busy working, and this "rock-drilling marvel" has set a new record here.

 

It is understood that the project is located in the Dachong old town redevelopment area, where construction must deal with challenges such as avoiding various underground pipelines, renovating old foundations, and difficulties in lowering casings. In addition, piling here requires drilling into slightly weathered granite, with a pile depth of 27 meters, a pile diameter of 1.2 to 2.2 meters, and a pile depth of 2 to 5 meters; there are many boulders, the longest being 17 meters, with a pile diameter of 2 to 2.2 meters and boulder strength of 110 to 120 MPa.

 

The equipment used for this project consists of six Sany units in total: SR360, SR420, and SR630. During construction, the user innovatively adopted "graded drilling with different drilling tools and methods," replacing the traditional pick teeth with roller bits.

"This makes the equipment better suited to piling work. We even drilled a miraculous circle and achieved no sediment at the pile bottom," Chief Engineer Yang at the site told the reporter. "Rock-drilling stability is also better." Good equipment alone is not enough; one must also understand the construction method and know the equipment operating techniques. Regarding efficiency, Chief Engineer Yang told the reporter, "When drilling through very large boulders, one pile takes three days. Overall, the six machines at the site ensure at least four piles are completed per day."