The Automatic Trip Hammer is designed for carrying out the Standard penetration Test (SPT) to BS 1377: Part 9: 1990. SPT Drive Rods and a split Tube Sampler are connected to base of the anvil, and driven into the ground by the falling weight.
The hammer comprises a drop weight of 63.5 kg and a pick-up and selftripping mechanism that ensures the weight has a free fall of exactly 760mm.
The inner shaft acts as a guide on which the weight drops with minimal resistance and strikes the anvil squarely.
The trip hammer is supplied with a Safety retaining bolt to prevent the weight from sliding when the hammer is not in use or during transport.
Tandard penetration tests (SPT)are carried out at regular intervals of depth in soil layers to assess the in-situ compactness of various soil layers.
SPT is by far the most popular and economical method of obtaining subsurface information. A number of foundation design procedures make use of SPT results. The test is carried out by driving a split spoon sampler of specified dimensions a distance of 46 cm into the soil at the bottom of the borehole. A 63.5-kg hammer falling free from a height of 76 cm is used to drive the sampler. Number of blows required to drive it 30.5cm is recorded as 'N' value.
|SPT SAMPLER || ASTM / BS|
|STANDARD PENATRATION TEST, spt drill rods||SPT drilve rods|