Soil sampling system with sample container rigidly coupled to drive casing by inflated gland

A fluid-coupled latch for a soil sampling system (including a sample barrel and a drive casing) includes an inflatable gland affixed to the sample barrel. When inflated, the latch engages the inner wall of the drive casing so that the sample barrel is held in a fixed position relative to the drive casing. The latch thus in effect rigidly couples the sample barrel to the drive casing so that the drive casing and sample barrel can be driven simultaneously into the soil while maintaining their initial relative positions. The pressure in the gland is regulated during sampling procedures. After the casing, barrel, and liners are advanced a selected depth into the soil, the latch is released by deflating the inflatable gland and the barrel and liners are removed using wire rope from a winch. The drive casing remains in the soil. An extension is attached to the drive casing. Empty sample liners are put into the sample barrel, and the sample barrel (with latch, inflation tubing, and wire rope attached) is lowered into the drive casing. The latch is then reactivated to secure the sample barrel. The drive casing, including extensions, and the latched sample barrel are driven further down into the soil. The procedure can be repeated until all desired samples are obtained. A clamp system allows the drive casing to be hydraulically retracted from the ground when sampling is finished.