Going underground has been proven an effective defense strategy. However, defense structures below the ground need to be designed for ground shock loading. In Singapore, two thirds of the land area is covered by residual soils which are mostly unsaturated. But soil moisture condition in a tropical country like Singapore can alternate between dry and wet conditions. This paper summarizes the findings of a series of small-scale field tests to investigate the effects of degree of saturation on ground shock. A new perspective is presented which will help in developing technologies to mitigate ground shock effects on underground structures in future.