Abstract: Relying on a deep-filled clay soil foundation treatment project in Hefei,the 8000 kN·m energy level strong slamming situation was introduced.Through the static penetration test,the standard penetration test,the indoor soil test,and the shallow flat plate load test,the changes of main physical and mechanical properties before and after dynamic compaction of the cohesive soil with 8 to 10 m cast,19.5% to 30.8% moisture content,and 17.6 to 21.8 plasticity index were analyzed.The effective reinforcement depth and reinforcement effect of high-energy-grade dynamic compaction in deep throw-in cohesive soil are studied.