A silty sand made from a seriously decayed red sandstone was reinforced by biaxial geogrid. A number of samples of this reinforced soil with 0

1

2

3

or 5 reinforcement layers at 90 %

95 % or 100 % of compaction degrees were used to measure their modulus of resilience in laboratory. The relationships were concluded between the resilient modulus of the reinforced soil and the location and the number of the reinforcement layers and compaction degree of the soil. It is proved by the test results that a greater modulus of resilience may be obtained when a proper location and a rational number of the reinforcement layers are applied to reinforce the soil with a high degree of compaction; and it is shown a smooth connection may be achieved between the rigid abutment and the soft subgrade soil by using biaxial geogrid to reinforce the embankment of bridge approach. Therefore

the bump at bridge-head may be controlled.