INTRUSION PREVENTING STRUCTURE

To provide an intrusion preventing structure which more effectively prevents an intrusion of a suspicious person from a quay wall without affecting normal berthing of a marine vessel.SOLUTION: In an intrusion preventing structure 10, fenders 12a,12b and a plurality of protrusions 14 fixed to an attachment member 13 vertically and horizontally with predetermined intervals are attached so as to be adjacent to a quay wall 11 in a crosswise direction. There, the maximum protruding length Lin a vertical direction of the protrusion 14 from the quay wall 11 is set to be shorter than the maximum protruding length Lin a vertical direction of the fenders 12a,12b from the quay wall 11 in a maximum design displacement of the fenders 12a,12b. On an abnormal berthing of a marine vessel and the like, the fenders 12a,12b which cannot absorb compressive force in an elastic region is compressed up to a position shorter than the maximum protruding length Lin a vertical direction of the protrusion 14 from the quay wall 11 (a position beyond the maximum design displacement of the fenders 12a,12b). Then, tips of the protrusions 14 become in contact with a side face of the marine vessel, and damage such as cracks or breakage cam be given to the marine vessel.SELECTED DRAWING: Figure 1 【課題】船舶の正常な接岸に影響を与えずに、岸壁からの不審者の侵入をより効果的に防止する、侵入防止構造体を提供する。【解決手段】侵入防止構造体１０では、防舷材１２ａ、１２ｂと、取付部材１３に縦横に所定間隔で固定される複数の突起体１４とが、岸壁１１に横方向に隣接するように取り付けられる。その際、突起体１４の岸壁１１から垂直方向の最大突出長さＬ３は、防舷材１２ａ、１２ｂの最大設計変位時における岸壁１１から防舷材１２ａ、１２ｂの垂直方向の最大突出長さＬ１よりも短く設定される。船舶の異常な接岸等において、弾性域で圧縮力を吸収できなくなった防舷材１２ａ、１２ｂは、突起体１４の岸壁１１から垂直方向の最大突出長さＬ３よりも短い位置（防舷材１２ａ、１２ｂの最大設計変位を超える位置）まで圧縮される。すると、突起体１４の先端部が船舶の側面に接触し、船舶に傷や破損等の損害を与えることができる。【選択図】図１