Just like China’s coastal areask,Dutch soils are very suitable for driving sheet piles and casings with vibratory hammers. Combination walls are a preferred method in The Netherlands as they provide excellent permanent retaining strength and with the right equipment can be driven very quickly into the ground. Combination walls require high precision positioning, which is made easy by using the right equipment: piling rigs and resonance free vibratory hammers. 

ICE’s parent company Dieseko manufactures both in a dedicated factory in The Netherlands; the equipment is available for purchase in China. A piling rig allows driving at a precise inclination,whether straight down (vertical),or at an angle of up to 45 degrees backward,or up to a maximum of 18 degrees forward. The piling rig is fitted with a pull down winch to increase driving speed,and is fitted with a jib has a special designed head which makes it easy to lift big casings without the need for an extra lifting crane. The rigs also come with hydraulically operated pile arms that guide the casing when it is driven into the ground. The user can also chose to install a pile lifting device directly on the hammer that hydraulically pulls piles into the hammers clamps.

In the application we discuss in this article our client Geka Bouw B.V. chose the 110M (comparable to the 1412C) to drive the 32 meter long,1420mm diameter, with 19mm wall thickness,21t casings and the ICE 50RF was used for the sheet piles combination. The 20 meter long interlocked sheet piles had a combined width of 225cm and were welded together and driven 3 at a time by three 175T clamps affixed to a single clamping plate. To save time and gain more control (Vibratory hammers clamp the casing with a hydraulic clamping system and eliminate the risk of a running pile) over the piling process the client chose a vibratory hammer to bring the casings three quarters into the soil. The last 8 meters of the casings were driven with an impact hammer to increase the end bearing capacity of the piles. 

The 50RF vibratory hammer is specifically designed to be attached to the 90PR or 160PR leader mast (max 36 to 51m leader length). The inclination of these rigs’ leader is measured by a digital inclinometer. This meter is integrated in the software of the rig and ensures the verticality of the pile to within specification. Without a rig driving this complicated set-up of casings and welded together sheet piles would be sheer impossible. The rig's pull down winch ensures the vibratory hammer can work optimally even in hard soil conditions,and drive the pile down fast. The piling rig’s mast (leader) can be lifted about 1500mm and lowered by 3000mm, allowing it to work below or above ground level. 

The picture series shows how Geka Bouw installed the combination wall for the construction of a new LNG storage and transshipment terminal in Rotterdam harbor.