A new 1911 km rail connection from Mongolia to China is being built to transport coal to fuel China’s coal fired power plants and steel industry. ICE was contracted by Xinjiang Beixin Road and Bridge Group to supply a vibratory hammer for the driving of sheet pile cofferdam for a major bridge construction at the MHJT-2 section of the project. The piles are No. 5 Larsen piles， 9 and 12 meters in length. Soil conditions in this part are challenging， the silty soil is very dense， with PS values close to 200MPa reported in the geological soil reports. These soil conditions pose a well-known challenge for sheet pile driving. The client had no prior experience driving sheet piles and after consulting expert opinion opted for a hydraulically driven vibratory hammer from The Netherlands. 

The main factor for success in dense soils is a hammer with a large amplitude and high frequency， this is a key characteristic of all ICE hydraulic hammers. As the sheet piles are quite short the 416L is sufficient to drive the piles quickly to depth. The 416L weighs in at just under 4 tons and does not require a large crawler crane.

The main challenge during driving is maintaining the verticality of the sheet piles， any deviation will create problems down the line and in the worst case affect the water tightness of the cofferdam. The hammer was operated free hanging， even though the hammer is well balanced this brings risk of driving out of line. A simple guide frame was laid out to guide the sheet piles into the soil and the 416L drove the sheet pile down in an average time of 80 seconds. During the driving the hydraulic flow is automatically adjusted to the load pressure to avoid generating a lot of heat in the gear box. The variable pump increases the efficiency of the equipment and reduces fuel usage.

The crane driver said: “compared to electric vibro’s with a similar spec I worked with before， the 416L has much lower resonance effect on my crane. The hammer is light， and compact in size， so my working reach is much larger and I don't have to reposition the crane every few meters wasting time that could be spent driving more sheet piles. I also noticed that my colleague who operates the hammer on the ground got the hang of it really quickly. After only a few days’ instruction and supervision by an ICE engineer we have been independently operating the hammer.”

Xinjiang Beixin was pleasantly surprised how effortless their first endeavor into sheet pile driving has been with the right choice of pile driving equipment. The project is on schedule and without stress. 

If you haven’t joined the market in using hydraulic hammers， why not rent an ICE vibro on your next job? Call us for more information today!