Picture a stone 石 being cut 切 and laid into place: 砌 is to build with stone or brick.
usage
Read qì for masonry work: 砌墙 (to build a wall), 堆砌 (to pile up, also to pad writing with empty phrases). A separate reading qiè exists only in the rare theatrical term 砌末 (stage props), which a learner will almost never meet.
Left stone radical, a pictograph of a stone slab below a cliff, the indexing component. 砌 names the act of building with stone or brick, laying course on course to make a wall or step. Same radical heads 砖, 碎, 碰.
Right 切 supplies the sound, qiē shifting to qì. It is 七 plus 刀 (knife), originally a precise cut. A faint semantic color: a 砌 wall is built from stones cut and fitted closely together.