One of CMW’s specialist geotechnical services is providing dynamic pile testing services tailored to meet our Clients’ project needs.
CMW have a number of trained professionals experienced in undertaking dynamic pile testing using the SIMBAT technique. All SIMBAT testing equipment is permanently based in Perth and available through a local specialist piling contractor. We can also arrange, with the specialist contractor, for the provision of piling rigs to undertake the dynamic loading if required.
Our point of difference is to provide a local WA focused, high quality dynamic pile testing capability that is cost effective, efficient and focused on the WA markets and conditions.
CMW Geosciences Pty Ltd adopts a hands-on approach to help Clients solve challenges and manage risk in, on and under the ground.
The SIMBAT technique is a dynamic pile test that allows the prediction of static load settlement behavior of bored, cast-in-place and pre-cast driven piles as well as driven steel tube and UB piles. It is recognised as a superior alternative to other systems, as it includes data validate features, such as a specifically designed optical theodolite.
The prime advantages of dynamic load testing are the speed of testing and relatively low costs compared to static load testing. Typically, up to 6 piles per day can be tested and preliminary results made available on the same day. The rates are dependent on access, preparation and type of drop weight used.
The method is based on analysis of the propagation of stem waves in long elastic cylinders. SIMBAT converts downward and upward (reflected) waves into forces and velocities and separates these to calculate the dynamic soil reaction. The conversion of dynamic to static reaction is then carried out using numerical simulation.
The general SIMBAT dynamic pile testing methodology is briefly summarised as follows:
- Install the test pile and mobilise pile driving rig/hammer
- Install instrumentation which comprises a theodolite target, with two strain gauges and two accelerometers attached to the sides of the pile;
- Apply the dynamic load by dropping a mass onto the top of the pile and record strain, acceleration and displacement for each blow;
- Repeat this process for a number of blows of varying drop height to establish a stress-strain relationship;
- Acceleration and displacement signals are then integrated using SIMBAT to establish corrected velocities;
- Further integration is then undertaken using SIMBAT to convert signals into upward and downward forces to calculate the dynamic soil reaction for each blow;
- Dynamic soil reactions are then plotted with pile penetration. These plots are then corrected into static loads to develop a static load curve;
All test data collected (acceleration, strain and displacement) is stored during the test and can be analysed immediately if required.
Full analyses are then completed and a dynamic test pile report provided within 1 or 2 days of the testing.