Perencanaan Ulang Rc Bridge No. 8 dengan Box Girder Beton pada Proyek Pembangunan Akses Tol Patimban Paket 1

Abstract

This study redesigns the superstructure of Bridge No. 8 on the Patimban Access Toll Road Project Package 1 from a conventional RC slab bridge (15 m span; total length ±453.7 m) to a prestressed concrete box girder as an alternative to improve construction efficiency and address delays. Secondary data utilizes shop drawings in accordance with SNI 1725:2016 and RSNI T-12:2004, as well as other relevant regulations. Modeling employs MIDAS Civil for validating support reactions. The evaluation covers prestress loss, service stress, deflection, and ultimate capacity. The results show a total prestress loss of 28.44% ≈ the assumed 30%, service stress meeting the allowable limits (σsk = −18.150 kPa; σst= 3.221 kPa), maximum deflection of 0.05012 m < L/250 = 0.200000 m and L/800 = 0.06250 m, as well as Mu+ = 92424 kNm and Mu- = 159372 kNm ≤ ФMn+ = 110053,7 kNm and ФMn- = 178169,2 kNm. Otherwise structure is save from shear as the results on table 4.33 and 4.36, so the structure is safe under service and ultimate conditions. Additionally, when checked against lifting conditions, the cross-section is deemed safe in withstanding its own weight against the lifting anchors and non-prestressed reinforcement. From a material perspective, the span configuration changes to 9 spans using 50 m per span, compared to the previous existing condition with 29 spans of 15 m each. Furthermore, the volume of concrete decreases from 3,872 m³ to 3,762 m³ (a reduction of 109.6 m³), indicating that the prestressed box girder is more efficient and has the potential to simplify the construction phases.