METHOD FOR FORMING RECESS ON OBJECT CAPABLE OF BEING EXCAVATED

To provide a method for forming a recess on an object capable of being excavated, the method being capable of securely and appropriately quarrying a block on the object capable of being excavated, such as a rock bed or a concrete body, from the outside to the inside in a depth direction and being capable of forming the recess efficiently.SOLUTION: A method for forming a recess on an object capable of being excavated includes: a groove formation step of performing work of excavating the object 1 capable of being excavated from the outside to the inside to form a contour groove P and segmentation grooves Q, to make blocks 3 to be quarried be in a state in which only their inside sides 3a are connected to the object; a block fracture step of providing a rock breaking device 9 in a segmentation groove to fracture the blocks from the object using the rock breaking device; and a recess formation step of removing, from the object, the blocks fractured from the object to form the recess on the object. In another segmentation groove adjacent to the segmentation groove in which the rock breaking device is provided, a filling 15 for obtaining reaction force against expansion force F of the rock breaking device is provided.SELECTED DRAWING: Figure 9 【課題】岩盤やコンクリート体などの掘削可能な対象物に、外部から深さ方向の内奥へ向けて、確実かつ適切にブロックの切り出しを行うことが可能で、効率よく凹所を形成することが可能な掘削可能な対象物への凹所形成方法を提供する。【解決手段】掘削可能な対象物１の外部から内奥に向け、輪郭溝Ｐ及び区分け溝Ｑを掘削する作業を行って、切り出すブロック３を、その内奥側３ａのみが対象物とつながっている状態にする溝形成工程と、区分け溝に割岩装置９を設置し、ブロックを割岩装置で対象物から破断するブロック破断工程と、対象物から破断されたブロックを対象物から撤去して、対象物に凹所を形成する凹所形成工程とを含み、割岩装置が設置される区分け溝に隣接する他の区分け溝には、割岩装置の拡開力Ｆに対する反力を得るための詰め物１５が設けられる。【選択図】図９