Technical Challenges of Large Movable Scaffolding Systems

Abstract

For this span range (70-90 m), as recent studies have proven, 1 the spanby-span construction also ensures important advantages such as continuity of the deck and a significant optimization of material consumption (in particular that of prestressing steel) because the construction stage may be almost neutral to the deck design.Until the last few years, bridges with 70 to 90 m span were typically constructed by precast solutions, metallic solutions or cantilever method. 2

New Frontiers in Multi-span Prestressed Concrete Deck Construction: A Case Study

“…In 2009, the first "OPS bowstring" concept was applied. 13 In 2018, the first OPS-strengthened LMSS application for a 90 m span was concluded. 21 A synopsis of the previous research is presented in Fig.…”

“…The major challenges to overcome to ensure the adequacy of the LMSS for the proposed method, as discussed before, 8,13 were:…”

“…in terms of LMSS weight: to ensure that the LMSS was not governing the deck design, an LMSS global traveling mass below 1500 tonnes was to be achieved . in terms of LMSS main girder midspan deflection: to ensure that the LMSS mid-span deflection was lower than L/1000 (where L is the span) 13 . in terms of LMSS productivity: to ensure a target working cycle of 14 days (45 m/week), to achieve a much better production cycle than could be obtained with four pairs of form travelers (30 m/week = 4 × 2 × 3.75 m/week), where 3.75 m is the average segment length .…”

“…11,12 These studies created relevant optimization possibilities, in particular, for spans above 70 m. Knowing this, in 2011, the authors developed an interim study where the potential uses of an OPS application on an MSS were summarized and the technical challenges of LMSS implementation were identified. 13 Until 2015, complementary studies were developed to prepare the systematic application of LMSSs to a 70-100 m span range. 4,14 These R&D works included numerical and experimental tasks, and benefited tens of worldwide applications comprising the emerging OPS technology.…”

Construcción de vanos de 90m con cimbra autolanzable

“…En el mismo período, se publicaron estudios sobre estadísticas de construcción y gastos de materiales asociados a distintos métodos constructivos [1] [8], en los cuales se concluye que el método de construcción de tableros vano a vano con hormigonado in situ puede resultar en una reducción significativa de las cuantidades de los materiales del puente, en comparación con otros métodos constructivos. Esta tendencia aumenta con incremento del vano, siendo destacada la posibilidad de una optimización relevante para vanos con luz superior a 70 m. Con esta premisa, en 2011 los autores iniciaron el estudio de un concepto de cimbra autolanzable (M1) para alcanzar luces comprendidas entre 70 y 100m [9]. El M1 ha sido desarrollado entre 2011 y 2015, periodo en el cual se realizó la evaluación numérica y experimental de la solución [10] [11].…”