فناوری مقاومت لرزه ای تقلیدی
Abstract
1. Introduction
2. Prototype structure
3. Development of the specimen
4. Design considerations and construction of the specimen
5. Testing arrangement and instrumentation
6. Experimental results
7. Progressive collapse analysis
8. Acceleration-Displacement Response Spectrum Analysis (ADRS)
9. Implementation of emulative cast-in-place connections
10. Summary of research contributions
11. Conclusions
Acknowledgments
References
Abstract
Accelerated Bridge Construction (ABC) offers advantages such as rapid construction, limited traffic disruption, fast project delivery, cost savings for the formwork, more accuracy in construction due to prefabrication, better quality control, higher durability, reduced weight of the bridge structure, enhanced safety, and less environmental impacts. ABC has been successfully deployed in low seismic regions. However, given the uncertainty about the adequate performance of connections between precast elements, application of ABC in high seismic regions has been limited. The research investigates the use of two types of emulative connections in a precast bent. The column-to-footing connection consists of member socket, while the column-to-cap beam connection is grouted ducts. These connections intend to emulate the traditional formation of plastic hinges in the bridge columns during an earthquake. A half-scale specimens with emulative connections was tested under quasi-static cyclic loading. Experimental results showed adequate seismic performance of the specimen compared to cast-inplace construction.
Introduction
Accelerated Bridge Construction (ABC) has been gaining popularity among many Departments of Transportation (DOTs) in the United States, and other countries. Past studies on ABC include Billington et al. [1,2], Wacker et al. [3], Restrepo et al. [4], Marsh et al. [5], Mashal and Palermo [6], Sideris et al. [7], Mashal et al. [8], Haber [9], Khaleghi [10], and others. There have been many applications of ABC in low seismic regions. However, observations from the past earthquakes have raised concerns about seismic performance of the connections between precast elements (Buckle [11] and Hawkins et al. [12]). Emulative cast-in-place connections for bridge structures aim to achieve the common plastic hinging of the columns that occurs in castin-place construction. Over the years, a variety of these connections have been developed which includes bar couplers, grouted ducts, pocket, and member socket connections. From these emulative connections, the grouted ducts and member socket connections have been selected in this research. While these connections have been previously investigated in cantilever columns by Mashal et al. [8] and others, they had not been tested together in a precast bent system. Marsh et al. [5] presents a concept for a precast bent in seismic regions (Fig. 1). In this concept, column-to-footing connection is member socket, while column-to-cap beam connection is grouted ducts. A brief description of grouted ducts and member socket connections, are presented in the following sections.