ICE has just added a water pump to its rental fleet. Adding water jetting during pile driving reduces soil friction and allows our users to continue pile driving when refusal is met. Just like our vibratory hammers, the water jet pump is driven by a diesel engine.

Water Jetting

Pre-drilling and water jetting are techniques are commonly uses to reduce soil resistance, thereby facilitating sheet pile installation by vibratory hammer. Another reason for choosing to use water injections during the installation is to reduce any nuisance caused by vibration.

Water jetting theory
Water jetting is a process in which sheet piling is installed while water under high pressure is injected at the tip of the sheet pile or casing pile. This is done at a low level of discharge or debit (the flow rate per unit of time). This creates temporary water over-tension at the tip, enabling the sheet pile to be installed with less resistance and thus more easily and with less resonance. Because of the low debit of the pump, the soil recovers quickly and the soil’s properties undergo minimal change.

Our water jet pump has the following specifications:

Water Jetting in practice

Water Jetting is primarily used for pile driving in ground conditions that otherwise would be unsuitable for vibratory hammers due to either dense sands/gravels or stiff clays. A secondary benefit of water jetting is that it significantly improves the daily pile installation rate.

For constructions sites with coarse granular soils, the main function of the water jet is to oscillate the soil particles, reducing the ground’s resistance to pile penetration.

When sheet piles are being installed into cohesive clay soils, the lubricating action of the water reduces the amount of adhesion that reduces the amplitude. At the same time, at the toe end, the water reduces resistance, making it easier for the piles to penetrate the ground.

Water jetting is carried out via a high-strength steel jetting lance pipe attached to the inside of the sheet pile. The jet is operated at low pressures in the initial stages of the installation. The jet is operated continuously throughout the installation to maintain a clear jet nozzle and the pressure adjusted in response to the ground resistance to enable the optimum penetration of the pile to be achieved with a minimum disturbance to the structure of the ground.

Advantages

·       Enables pile pressing into difficult soils such as very stiff clays and granular strata

·       Improves installation speed

·       Very short-term disturbance to the soils

The jet pump is available from the ICE rental fleet. Contact your ICE sales representative to find out if how water jetting may benefit your next project!