Redesign of the Superstructure of a Hospital Building Using a Steel–Concrete Composite System

(Case Study: Medical Building Phase 3 of Siti Khodijah Hospital, Sepanjang)

Abstract

The redesign of the superstructure of the Phase 3 Medical Building at Siti Khodijah Hospital, Sepanjang Branch, was carried out to improve performance under lateral loads. The design complies with SNI 1726:2019, SNI 1727:2020, SNI 1729:2020, SNI 2847:2019, SNI 7860:2020, and ANSI/AISC 360-16. Based on the analysis results and composite structure design provisions, the floor slabs are designed as composite slabs using 0.75 mm thick steel deck with a total slab thickness of 131 mm. Secondary beams use WF 350.175.7.11 and WF 346.174.6.9 sections, equipped with D19 shear connectors spaced at 320 mm. Main beams use WF 800.300.14.26, WF 400.200.8.13, and WF 346.174.6.9 sections, with D22 shear connectors spaced at 640 mm and 320 mm. Primary columns are designed as concrete-filled tubes (CFT) with HSS 700.700.25, HSS 700.700.19, and HSS 350.350.12 sections. Column base plates measure 900 × 900 mm with a thickness of 50 mm and are anchored using eight M30 anchor bolts. The staircase structure is designed with steel construction, where the main stringers use WF 300.150.6.5.9, landing beams use WF 350.175.7.11, and platform beams use WF 100.50.5.7. Stair bracing uses L 60.60.5 angles, while the tread and platform plates are 6 mm thick. Stair base plates measure 800 × 450 mm with a thickness of 10 mm and are anchored using four M12 anchor bolts.