In this technique, a circular hole is excavated up for the depth at which the soil will stand unsupported (about 0.5m for soft clay and 2m for rigid clay). Vertical boards often known as laggings, are then set in place around the excavated encounter and they are held tightly in https://royelvis-band35522.elbloglibre.com/30580270/not-known-facts-about-drilled-pile-foundations-bd