Underground water storage tank and underground infiltration tank

摘要

PROBLEM TO BE SOLVED: To provide an underground water storage tank and an underground seepage tank having a filler member filled therein exhibiting a large resisting force against a load placed thereon although they are provided with a capability of being packed in a less-bulky compact configuration, conveyed and stored. SOLUTION: In the underground water storage tank B a large number of the filler members A are filled in a water storage space formed underground and an impermeable sheet 4 is laid on outside faces and bottom faces of the filler members A. The filler member A comprises a plurality of support elements made of rod material having fitting connection parts on a top end and a bottom end thereof respectively and a plurality of connecting elements having fitting parts, which are arranged vertically and horizontally, fitted into the fitting connection parts of the support members so as to be connected to the fitting connection parts. The underground infiltration tank has a water storage space formed underground and a large number of the filler members A are filled therein.