WATER CUTOFF STRUCTURE

PROBLEM TO BE SOLVED: To provide a water cutoff structure, quickly installable, and capable of also exhibiting high water cutoff performance.SOLUTION: A water cutoff structure 1 of a clearance between a water cutoff plate 50 installed in an opening 2a of a building and a doorway of a subway and damming up infiltration of water and a support member 7 for supporting the water cutoff plate 50, and is the water cutoff structure 1 for installing a water absorptive expansive material 8 on the water cutoff plate 50 so as to expand in the clearance. Since the water absorptive expansive material 8 expands in the clearance between the support member 7 and the water cutoff plate 50 by absorbing water, the water absorptive expansive material 8 can block up the clearance. Thus, there is no need to seal gas or liquid by providing a water cutoff tube in the clearance between the support member 7 and the water cutoff plate 50, so that water cutoff performance can be exhibited only by providing the water absorptive expansive material 8 in the clearance. Thus, a water cutoff countermeasure can be quickly taken even to risk of sudden flooding such as torrential downpour.SELECTED DRAWING: Figure 1 【課題】迅速に設置ができ、かつ、高い止水性を発揮できる止水構造を提供する【解決手段】建物の開口２ａや地下鉄等の出入口に設置して水の浸入を堰き止める止水板５０と、前記止水板５０を支持する支持部材７と、の間の隙間の止水構造１において、前記隙間で膨張するように吸水性膨張材８が前記止水板５０に取り付けられていることを特徴とする止水構造１。吸水性膨張材８は、吸水することで支持部材７と止水板５０との隙間において膨張するので、吸水性膨張材８が隙間を閉塞することができる。このため、支持部材７と止水板５０との隙間に止水チューブを設けて気体もしくは液体を封入する必要がなく、隙間に吸水性膨張材８を設けるだけで、止水性を発揮することができる。これによって、ゲリラ豪雨のような突発的な浸水のおそれに対しても迅速に止水対策を講じることができる。【選択図】図１