## 2 Literature Review  
### Development of Movable Scaffolding System with an Organic Prestressing System  
The evolution of bridge construction materials has progressed from stone to reinforced concrete, leading the advancement of construction methods. Furthermore, the innovation of prestressing technology has realised longer bridge deck constructions with continuous spans, aiming to reduce construction costs and duration, which inspired the development of movable equipment. As introduced by [PERSON] [8], the equipment can be roughly divided into two groups depending on the construction forms, which are prefabricated or cast in situ decks or segments. To build cast in situ bridge decks, there are three groups of equipment including movable formwork tables, Movable Scaffolding Systems (MSSs), and formwork travellers [8]. The span-by-span method, exemplified by the MSS, changes bridge construction by enabling incremental launching and the successive displacement construction method for both cast in situ and prefabricated bridge decks [9]. The MSS, first introduced in 1959, offers economic advantages for viaducts and railway bridge construction by reducing auxiliary equipment and ground works [10]. It employs robust steel structures, hydraulic or rotary traction systems, and prefabricated decks for efficient assembly and movement. Prefabricated elements, connected via prestressing or epoxy resin, allow for spans of up to 80 m [9]. Such scaffolding systems can be classified as overhead or underslung depending on the position related to the bridge decks, adapting varying geometries [8]. The primary structural element of the MSS is the launching girders, featuring solid or trussed webs with different strength and flexibility [9]. The modular nature of these systems facilitates efficient reuse and transportation across projects, highlighting their role in modern bridge construction [10]. In addition, the application of an OPS in the MSS represents an advancement for managing higher loads and spans in bridge construction, particularly beneficial for HSRBs. Although it introduces complexities such as fatigue and response delays, the cost-to-benefit ratio remains favourable, underscoring the evolving nature of bridge construction technologies [9]. The Overhead Movable Scaffolding System (OMSS) model M1-90-S developed by BERD Company in Portugal will be redesigned based on the Australian building codes in this project. This bridge construction equipment (BCE) is initiated after the innovation of Organic Prestressing System (OPS) technology led by [PERSON] in the 1994, as part of the research and development program supported by the Faculty of Engineering, University of Porto, Portugal. The initial research on this technique was in Portuguese [9; 11]. The innovation of organic prestressing is inspired by the structural system in nature. It can be considered an effector system (known as an \"artificial muscle\" or active control system) that can modify the strength of a structure and be applied to resist quasi-static loading [12]. [PERSON] and [PERSON] [13] outlined adaptive prestressing technology that increases structural slenderness and lightness and reduces prestressing losses by 50% and suggested future research on deformations, vibrations, and fatigue under high live-load/dead-load ratios. Fatigue failure should be monitored and analysed for structure under vibrations [14]. MSSs were chosen as the first prototype to apply to OPSs due to their high live-load/dead-load ratio, with a scaled model of a trussed girder tested for structural feasibility [9]. An OPS uses sensors like strain gauges and accelerometers to gather structural data, which are processed by explicit controllers using pre-embedded algorithms to adaptively apply prestress via hydraulic actuators, successfully controlling mid-span girder deflection during simulated concrete casting [9].