Experimental and Numerical Study on Ground Shock in Loess under Ground Surface Explosions

To study the ground shock in loess soil subjected to ground surface explosion, field tests were conducted with the scaled distance of measuring points ranging from 0.328 to 1.73 m/kg1/3. Then, a refined numerical model was established using LS-DYNA and validated by experimental results. The widely used TM 5-855-1 manual for calculating ground shock loads was critically examined, revealing limitations in predicting impulse for scaled distances longer than 0.5 m/kg1/3. Accelerations calculated by the TM 5-855-1 manual and the China empirical formula underestimated measured data, with maximal errors reaching −86% and −80.1%, respectively. The recommended tr/ta of the TM 5-855-1 manual differed significantly from experimental and numerical results. Finally, modified formulas for ground shock load calculation in loess soil subjected to ground surface explosion were proposed, which is applicable in the scaled distance ranging from 0.35 to 2.0 m/kg1/3. The modified formulas accurately predict peak pressure, impulse, and rising time, serving as valuable references for ground shock load calculations in loess soil.