It depends of the resistance of soils, but the PANDA® can be made to reach 5 to 7 m in classicals soils (<10 MPa). However, in certain cases, it will be only a few centimeters (e.g. rocks). The softer the soil, the deeper you can go. In exceptional circumstances, we have known tests done to 17 meters. When doing soil investigation using the PANDA® (with the 4 cm² lost cone), the main reason to stop a PANDA® test is because of lateral friction on the rods. If you cannot turn the rod with your hand, it means that the lateral friction becomes important and then the value qd in MPa is not only the resistance under the cone (which is the principle of the DCP), but the resistance under the cone added with the resistance along the rods. The qd value will be higher than it should be and we are not able to quantify this error. The operator has to take this into account. The lateral friction will appear normally more rapidly with sandy soils than with silty soils or clayed soils. Sandy soils will collapse more easily into the hole (and generate lateral friction on the rods) than clayed soils. This can be overcome with a 20mm PVC plastic pipe sleeve following the sacrificial cone (larger diameter than the rod) as it is driven into the ground.
What is the Maximum Depth that the PANDA® can reach?
Apr 22, 2022