Modifikasi Desain Jembatan Kutorejo Kabupaten Nganjuk Menggunakan Struktur Busur Baja Through Arch

The bridge is a transportation infrastructure that has an important function in connecting two areas separated by obstacles such as rivers and others. Kutorejo Bridge is a bridge located in Nganjuk Regency that connects two areas traversed by the river with a span of 50 meters. From the data obtained including the image of bridge planning, the author tried to modify the design of the bridge by using a steel arc structure through arch bridge. The purpose of this study is to be able to plan the upper structure in the form of steel profiles and joints and lower structures in the form of abutment and pile cap bridge.  Analysis of bridge structure using structural modeling software by referring to loading in accordance with SNI - 1725 - 2016 on bridge loading while calculating the strength of materials used SNI - 1729 - 2015 on steel structure planning. The result of this study is the profile of the structure used in the planning of kutorojo bridge, which includes elongated girths using WF 500x200x10x16, transverse hashtags using WF 900x300x18x34, main gelagars and arches used box square 1200x1000x30x30. In addition, an important element in the planning of steel jemabtan is the sambugngan sedan, the connection used is a bolt connection which includes bolt joints on the elongated girder joint – transverse hashtags are used bolts measuring 16mm in diameter with the number of bolts 5 located on elongated girths and 10 located on transverse hashtags. Bolt joints on transverse gelegar – the main girder used bolts measuring 24mm in diameter with the number of bolts 5 located on the transverse girder and 10 located on the main girder. Bolt joints on the main girder – the arch used bolts measuring 20mm with the number of bolts 18 located on the main girder and 18 located on the arch. The final stage of planning this bridge is the planning of the lower structure which uses an abutment structure. Based on the results of the reservoir, the dimensions of the abutment used have an abutment wall height of 5.2 m and a width of 1.3 m with the main reinforcement attached 490 D36 and the attached zinc bone D16-200 Keywords: Bridge Structure Modification, Through Arch Bridge, Bridge Structure Planning, Steel Stuktur, Bolt Connectio