To　effectively　protect　the　underground　structures　subjected　to　ground　shock,　a　new　protective　component　made　of　foam　concrete　was　proposed.　Different　from　the　mechanism　of　the　solid　foam　concrete　layer　protection,　under　the　action　of　ground　shock,　the　proposed　components　firstly　exhibited　brittlely　fracture,　and　the　fractured　parts　underwent　recontact　and　compaction,　in　which　the　ground　shock　truncation,　load　transferred　reduction　and　load　form　modification　on　the　structures　were　achieved　with　the　response　of　the　designed　components.　A　field　experiment　was　conducted　and　the　comparison　of　the　dynamic　response　of　the　structure　(with　different　protection　scenarios,　i.e.　without　protection,　with　a　solid　foam　concrete　layer　protection　and　with　the　proposed　component　layer　protection)　suggested　that　the　superior　protective　performance　was　achieved　with　the　fracture,　recontact,　compaction　of　the　new　component.　Due　to　the　brittle　fracture,　the　load　transfer　could　be　significantly　reduced　under　a　relatively　low　ground　shock　level,　with　which　the　negative　protection　effect　using　solid　foam　concrete　layer　could　be　avoided.　Subjected　to　a　relatively　strong　ground　shock,　the　proposed　component　layer　tended　to　compaction,　and　its　protection　effect　gradually　approached　that　with　the　solid　foam　concrete　layer.　©　2022　Explosion　and　Shock　Waves.　All　rights　reserved.