Abstract: The influence of foundation self-weight stress on shear velocity has not been taken into account in the existing models for compaction degree measurement based on shear wave velocity, resulting in significant errors in the detection results of deep soil foundation. A test device of airport soil foundation shear wave velocity and foundation self-weight stress is designed to address this issue, and shear wave velocity test of silty clay of 98% compaction degree under variable stress condition is conducted. The unloading method is applied to eliminate the influence of soil sample deformation on the experiment, and a correlation model between the shear wave velocity of airport soil foundation and the foundation self-weight stress is established. And the accuracy of the theoretical value calculated by the model and the measured value is 97.4%, verifying the effectiveness of this model. The results show that under the condition of 98% compaction degree, the foundation self-weight stress increases from 0 kPa to 250 kPa, and the shear wave velocity increases 287.49 m/s, which shows a good logarithmic function relationship. And the shear wave velocity of soil foundation shows an increasing trend from rapid to slow with the increase of stress. Under the same condition of soil compaction degree and optimal moisture content, the shear wave velocity of soil foundation increases with the deepening of foundation depth.

Key words: airport soil foundation, shear wave velocity, foundation self -weight stress, compaction degree, unloading method, foundation depth