Dynamic Load Testing involves the measurement of force (F) and velocity (v) at the head of the pile typically after installation by instrumenting the pile with strain gauges and accelerometers.
The hammer impact induces a compressive stress wave which travels down the pile with a constant wave speed (c) and reflects upward traveling compression and tension waves due to changes in pile and soil properties which are measured at the head of the pile.
By striking the pile with a drop hammer, the force and velocity at the pile head can be measured. Using stress wave theory, the measurements are analysed to predict the pile bearing capacity. Further computer analysis using CAPWAP software yields a variety of pile performance data including shaft resistance distribution, toe bearing and static load v deflection data.