Shenzhen Suifeng Construction Engineering company was established in 2006, and in a span of ten years has developed into a leading foundation specialist in Guangdong Province.
 
I first established cooperation with Suifeng in 2012. Suifeng’s philosophy is to take on challenging projects with high performance equipment, and this was the first time the CEO Mr. Ning used a hydraulic vibratory hammer for his bore pile foundations. Suifeng now has a fleet of Bauer and Sany bore pile rigs and takes on up to 20 foundation projects a year. The projects vary in complexity, some have layers of backfill, others silt sandy or gravel conditions that require additional steps in the construction process to guarantee pile integrity. After several rental periods, Suifeng decided that for the best result in challenging working conditions at the Qianhai development zone an ICE 1412C vibratory hammer was needed.


 
The construction of Internet Plaza commenced in March 2017. The project is led by the Third Bureau of China Construction Group. The site is part of the development of the Shenzhen Free Trade Zone and the Shenzhen Transportation Hub, about which we reported earlier this year. The site is near Qianhai Bay, an area that has been reclaimed from the sea. The top soil layers, about 15m, consist of backfill and silt and this complicates the bore piling procedure. The poor soil conditions necessitate the driving of temporary steel casings. The pile diameters in this project ranged from 1200-3100mm. The 1412C hammer’s 230t driving force is well suited to the driving and extracting of these casings.


 
The cast in place construction method is well established, the novelty lies in the use of a hydraulic vibratory hammer to build the pile at excavation level prior to the excavation work, while also increasing construction speed and pile integrity.
 
The installation method is as follows:
 
·Construction of the retaining wall - secant bore pile wall (contiguous bored pile wall) built by rotary drilling rig.
·Foundation Pile construction – vibrated steel support casing rotary drilling rig
·Boring process – Internet Plaza will have a 3-story basement and excavation will be 9 meters. To meet tight deadlines the foundation pile construction was started before the retaining wall was completed. In order to save concrete, Suifeng used steel casings to bridge the 9 meter backfill layers to the excavation level. After the rotary drill rig finished pile construction, the casing was extracted to be reused on an adjacent pile foundation, and the 9m hole that was left in the top layer was backfilled with material.
·This method eliminates the need for pile cutting as the foundation pile is cast to exactly the required length.
 
As retaining wall construction and pile foundation work can be carried out simultaneously, this method reduces construction time significantly, it does however require good site management to make sure the surface can support the weight of the construction equipment moving around on ground level. A fleet of excavators and shovels is busy around the clock filling up the holes with dirt and backfill materials. At the start of the excavation of the basement, the buildings foundation piles will already be finished.
 


For large foundation pile diameters this really is the only viable working method, if the pile is built tot surface level and then cut off at excavation level later enormous amounts of concrete are wasted.
 
ICE is an enthusiastic partner in introducing and supporting new construction methods. Get in touch with me to discuss how we can help you increase efficiency and reduce your environmental impact to your construction sites' immediate surroundings.