Correct Answer - Option 1 : Settlement of the test plate
Plate load test is a field test to determine the ultimate bearing capacity of soil, and the probable settlement under a given loading.
The bearing plate is either circular or square, made of mild steel of not less than 25 mm in thickness and varying in size from 300 to 750 mm with chequered or grooved bottom.
The plate is provided with handles for convenient setting and centre marked. As an alternative, cast in situ or precast concrete blocks may be used with depth not less than two thirds the width.
The test pit is usually at the foundation level, having in general normally of width equal to five times the test plate or block, shall have a carefully levelled and cleaned bottom at the foundation level, protected against disturbances or changes in natural formation.
The test pit should preferably have steps to conveniently go in the pit for setting and for taking observations.
In plate load test a graph between load and settlement of plate is plotted to find the bearing capacity of the plate.
the main observation of the plate load test is settlement of the test plate.