رفتار سیستم کابل لنگراندازی از جنس کامپوزیت بتن فولادی Behavior of steel-concrete composite cable anchorage system

1. Introduction A self-anchored suspension bridge is a suspension bridge in which the main cables are anchored to the stiffening girders of the bridge. It is gradually favored by bridge engineers owing to their artistic appearance, economic benefit, and good adaptability to various topography and geological conditions (Lonetti and Pascuzzo 2014, Qiu et al. 2014, 2009, Nie et al. 2011). This type of bridge is competitive and frequently used for small and medium spans in urban areas (Xu et al. 2017, Lu et al. 2014). When comparing with the conventional earthanchored suspension bridge, no massive anchorages are needed in this type of bridge (Votsis et al. 2017, Jung et al. 2014, Kim et al. 2006). The stiffening girder of a selfanchored suspension bridge carries both the live loads and large horizontal component forces of main cable tension, which makes the main girders become compressive-flexure members (Choi, et al. 2014, Gűnaydin et al. 2014). Consequently, the mechanical behavior of this type of bridge is more complicated than that of an earth-anchored suspension bridge. There are four types of cable anchorage systems that are generally applied to self-anchored suspension bridges to transfer the main cable force. The first type is the traditional concrete anchorage system, which is generally large in size. The Guangdong Foshan Pingsheng Grand Bridge that was built in China is a typical application of this anchorage system (Hu et al. 2004). The second type is the loop concrete anchorage system, which was applied to the west anchorage of the new San Francisco-Oakland Bay Bridge main suspension span (Sun et al. 2004, 2002). However, there are some disadvantages of this system, such as the complicated site construction technology and mechanical behavior of the prestressed concrete anchorage cap beam, the increased strand consumption of the main cable, etc. Then the pure steel anchorage structure is proposed. The Sanchaji Xiang River Grand Bridge in China (Shao et al. 2006) and the Yong Jong Grand Bridge in South Korea (Gil and Choi 2001, 2002) are the representative projects that this anchorage system was used. However, there are some concerns that should be concentrated like a large steel consumption, dense stiffeners inside the steel box, resulting in the complicated construction technology, etc. According to the major disadvantages of the three anchorage systems as mentioned above and based on the previous relative studies (Cui et al. 2017 a, b, Gou et al. 2017 a, b, 2015, Ju and Zeng 2015, Allahyari et al. 2014, Papastergiou and Lebet 2014), this paper studied a new type of steel-concrete composite anchorage system and focused on the mechanical behavior and force transferring mechanism. This anchorage system simplifies the structure of pure steel anchorage system, reduces the steel consumption, and improves the reliability of the weld between steel plates.