Seismic evaluation of friction spring‐based self‐centering braced frames based on life‐cycle cost

Abstract

In recent decades, a variety of self‐centering braces (SCBs) have been developed to address the limitations of conventional frames by decreasing residual drift due to earthquakes. However, the initial construction cost of self‐centering (SC) structures is expected to be higher and the study about its cost‐effectiveness over the life‐cycle span is limited. This paper presents a seismic life‐cycle cost evaluation of emerging friction spring‐based self‐centering braced frames (SCB‐Fs) compared with traditional buckling restrained braced frames (BRB‐Fs) when an existing structure is upgraded. Particular focus is on the effect of residual deformation, initial construction cost, and high fatigue performance of the SCB. Following the performance‐based design of the SCB‐F and BRB‐F, system‐level analyses are conducted. Numerical results of case‐study buildings indicate that the total expected annual loss (EAL) of the BRB‐F increases by approximately three times when the effect of residual deformation is considered, while its effect on the total EAL of the SCB‐F is negligible. Besides, the superior performance of the SCB‐F compared to BRB‐F is highlighted by a substantial reduction in EAL induced by earthquakes. In addition, the acceleration‐related seismic losses of SCB‐F constitute approximately 44% of the total EAL. Its contribution is significantly larger in the case of the SCB‐F compared to the BRB‐F. From the perspective of economic benefit, increasing the structural life‐cycle span is beneficial to the SCB‐F compared to the BRB‐F. The high fatigue performance of the SCB is favorable to increase the economic benefit of the SCB‐F, especially when the reduction of repair time is considered. The economic benefit of the SCB‐F compared to the BRB‐F is highly related to the initial construction cost. Taking the 100 years as an expected life‐cycle span, the high initial construction cost of the SCB‐F would not be paid off when the unit cost of the SCB is about 2.1 times that of the BRB.

Life‐cycle benefits estimation for hybrid seismic‐resistant self‐centering braced frames

“…Table 10 shows the initial cost of beams and columns of the lateral force‐resisting systems in BRBF6, SCBF6, and HSBF6. One BRB's cost was taken as about $10,000 based on FEMA P‐58 31 and prior studies 42 . In reality, the SMAB's and VD's costs highly depend on the quantity, construction location, and so forth.…”

“…One BRB's cost was taken as about $10,000 based on FEMA P-58 31 and prior studies. 42 In reality, the SMAB's and VD's costs highly depend on the quantity, construction location, and so forth. The ratio of the initial construction cost of SMAB or VD to that of BRB is defined as a parameter BCR.…”

“…Compared to structural dynamic responses, the life-cycle costs can provide a more valuable and clear reference to building owners or decision-makers. The life-cycle cost estimation method has been used to quantify the seismic performance of various structural systems in past investigations, such as reinforced concrete buildings, 35,36 steel moment-resisting frames, [37][38][39] steel frames equipped with steel panel walls, 40 base-isolated buildings, 41 SCBFs, 42,43 and so forth. However, no past studies were conducted to investigate the life-cycle cost of the recently emerging hybrid self-centering structural system and highlight its benefits in comparison with traditional structural systems.…”

“…However, no past studies were conducted to investigate the life-cycle cost of the recently emerging hybrid self-centering structural system and highlight its benefits in comparison with traditional structural systems. Moreover, only limited work considered the effects of RIDs, and most of the existing work 37,42 investigated the structural life-cycle cost based on the mean responses of the whole building but not the responses of each floor, leading to inaccurate results.…”

Seismic mitigation performance of shape memory alloy flexible circumferential joint in shield tunnel

“…The superelasticity of SMA will form hysteresis loops during cyclic loading, which can dissipate energy and is a good material for vibration control. [19][20][21] At present, SMA has achieved good applications in seismic mitigation of civil structures, including isolation devices, energy dissipation devices and displacement control devices. [22][23][24][25][26][27] An SMA ring spring is composed of an SMA ring and two steel rings (Figure 1).…”