## 1 Introduction
The isolation system and self-centering system are widely investigated [22; 23; 24; 25] and proved to be effective in decreasing the seismic vulnerability and improving the seismic performance of bridges. Although these new tall-pier bridges have better seismic performance and some of them have been used in the engineering practice, the problem of complex construction, and time-cosuming repairment still exists, their seismic design concepts and design methods are not systematic and updated. In 2003, [PERSON] et al. [26] put forward the conceptual framework of seismic resilience and aroused wide attention in the field of civil engineering. With the development of seismic technology and the resilient design concept of engineering structure, more and more effort are paid to the research of earthquake-resilient structures. In recent years, the seismic design concept of bridges has developed from earthquake-resistant to earthquake-resilient. Moreover, seismic resilience is the theme of the 16 th World Earthquake Engineering (16 WCEE, 2017) [27]. Based on the design concept of seismic resilience, considerable methods, such as rocking structure, self-centering structure, replaceable component and so on have been proposed and used in the engineering practice. [PERSON] and [PERSON] [28] proposed the design concept of \"structural fuse\" when studying eccentrically braced steel frames. [PERSON] et al. [29] firstly proposed the design concept of the replaceable steel main tower that consists of steel columns and beams when designing the east span of the new San Francisco-Oakland Bay Bridge. [PERSON] and [PERSON] [30] further concluded that the steel coupling beam served as a \"structural fuse\" and yielded while the tower column remained elastic under moderate and strong earthquakes. Since then, more and more experiments and theoretical research were conducted to develop the replaceable components in bridges. Some typical examples include the bi-steel columns with buckling restrained braces (BRB) and the bi-steel columns with steel energy dissipating coupling beams [31; 32; 33]. Currently, the research of replaceable component structure system in bridge engineering concentrates on multi-column pier with BRB and multi-column pier with steel plate shear link and they are mainly applied in the medium and short pier bridges. [PERSON] and [PERSON] [34] conducted quasi-static tests for RC bridge bents retrofitted using BRBs. The results demonstrated that the BRBs could be replaced immediately after large plastic deformation. [PERSON] and [PERSON] [35] proposed a design procedure for bridge bents with BRBs; the authors pointed out that BRBs could reduce the vulnerability of bridge bents at various damage states under both near-fault and far-field motions. However, the above research focused on short-to-mediate pier columns while few investigations on bridges with tall pier columns have been reported to date. The application of the replaceable component structure in bridge engineering remains an unsolved issue. Due to the \"strong beam - weak column\" principle in the seismic design of the bridge, pier columns are designed as ductile elements that may be damaged in a strong earthquake [36]. To improve the seismic performance and avoid the time-consuming repairment of the tall-pier bridge, especially under near-fault ground motions, a new type of tall pier, is firstly proposed in this study based on the design concept of seismic resilience. The newly proposed composite tall pier consists of four-limb concrete-filled steel tubular (CFST) columns and energy dissipating mild steel plates (EDMSPs). The vertical axial loads are mainly resisted by the CFST columns due to the sufficient bearing capicity. The EDMSPs serve as both energy-dissipating components and sacrificial components. Meanwhile, the I-shape steel beams are installed with some intervals to connect the four limbs of the CFST column. Figure 1 shows the sketch of the new composite tall pier.