To prevent reserved liquid from flowing out on the around even if an accidental breakage occurs on a reservoir wall by bonding and fixing a reservoir bottom periphery to a lowermost air chamber in an expansion-type liquid reservoir tank equipped with the wall comprising the air chamber vertically coupled outside the wall of the reservoir.

A transportable liquid reservoir tank for reserving muddy water or the like has a plurality of air chambers 2 airtightly bonded to one another outside a wall of a reservoir 1. A reservoir bottom periphery bonding part is bonded and fixed to a lowermost air chamber 2b, wherein an air chamber bottom cloth 9 for covering the entire reservoir bottom is bonded and fixed to the air chamber 2b. Thus in addition to the reservoir 1, a tank comprising the air chambers 2 and the air chamber bottom cloth 9 is formed. A connected reinforcing part 6 is formed on an upper face inside an uppermost air chamber 2a, while a connection string 7 is used to couple with a connection 8 on an upper part of the reservoir 1 for fixing to the uppermost air chamber 2a. A valve 4 is provided outside each of the air chambers 2 so that air can be injected and discharged.