its sketch is shown in Fig. 3. In the simplified in situ DST, a latticed shearing frame, which is equivalent to the upper half of the shear box in the conventional DST and made of high-strength steel, is buried in the ground to be tested, and then is compacted in the same way it would be in the real construction process. Several latticed shearing frames with different sizes are prepared for testing materials with different grain sizes. For coarse-grained rockfill, a latticed shearing frame with a size of 122.5 cm × 122.5 cm × 16 cm is usually used. For gravel or sandy soils, the latticed shearing frame can be reduced to 63.2 cm × 63.2 cm (area: 4000 cm2) × 16 cm or 31.6 cm × 31.6 cm (area: 1 000 cm2) × 10 cm. The shearing frame is pulled horizontally with a flexible chain attached to a heavy machine (e.g., a bulldozer) through an oil jack while a constant vertical (normal) force is applied. The shear force is measured with a load cell that is contained in the hollow center of the oil jack.