The Structural Design of Tall and Special Buildings

doi: 10.1002/tal.2137pmid: N/A

No abstract is available for this article.

Ju, Yanzhong; Zhang, Xinyuan; Wang, Dehong

doi: 10.1002/tal.70011pmid: N/A

The electrical safety gap between conductors and trees can be increased by substituting insulated cross‐arms for conventional cross‐arms, which is increasingly used in the rehabilitation of existing transmission lines. To study the seismic performance of insulated cross‐arm transmission tower structures, this paper establishes transmission single tower and tower‐line system finite model and performs mechanical analysis of the cross‐arm and nonlinear dynamic response analysis of the structure under 150 seismic conditions of different parameters. The relationship between seismic strength and structural response is fitted, and the seismic performance of the transmission tower structure is evaluated. The results show that by substituting insulated cross‐arms for conventional cross‐arms, the maximum displacement of the vertex of the single tower and tower‐line system model can be reduced by 20.43% and 111.83%, respectively; when PGA = 0.2 g, the probability of collapse of a single tower structure and a tower‐line system can be reduced by 0.49% and 11.66%, respectively. The research in this paper provides a useful reference for the further application of insulating cross‐arms.

Wu, Xiaoqin; Lu, Junlong; Shen, Lina; Tian, Penggang; Wang, Zhenshan; Tian, Jianbo

doi: 10.1002/tal.70013pmid: N/A

A method for identifying structural damage in masonry pagodas based on wavelet packet energy variation was proposed, with the change in wavelet packet energy of dynamic response signals before and after structural damage being used as the damage indicator. Finite element software was employed to establish a numerical model of the Kaiyuan Pagoda. By introducing different types of damage and applying seismic waves in three directions under four working conditions, a seismic response analysis was conducted. The acceleration response signals at feature points on each floor of the structure were subjected to wavelet packet transformation, and the wavelet packet energy was calculated. Based on the wavelet packet energy variation (DSI), damage indicators were determined, and structural damage identification was carried out. The identification results were compared with the preset damage. The results showed that, in the absence of noise interference, the damage indicators clearly correlated with the damage of the masonry pagoda, enabling accurate localization of the damage. Even when Gaussian white noise was added to the acceleration dynamic response signals, the indicators could still accurately identify the damage location, demonstrating good noise resistance. The research results provided an effective method for the damage assessment of masonry pagodas.

Yang, Xi‐Ling; Xiang, Yang; Li, Guo‐Qiang; Li, Hai‐Feng; Cui, Yi‐Qiong

doi: 10.1002/tal.70008pmid: N/A

For a seismic damper, an enlarged damping effect accompanied with a pronounced economic feature (e.g., smaller damper size) is always expected. Commonly, the damper is installed in or linked to the primary structure via some connecting components, whereas the damper and its connecting component act in series. Owing to the limited stiffness of the connecting component, the deformation of the damper could be suppressed, thus weakens the damper's efficiency. To deal with this problem, amplification devices such as the toggle‐brace‐damper and the scissor‐jack‐damper (SJD) have been proposed. In these proposals, a geometrical converting scheme is adopted to transfer the inter‐story drift of the structure to the stroke of the damper. Compared with the toggle‐brace‐damper, the SJD shows a smaller space demand and lower dependency on the stiffness of the connecting components, thus exhibits a better potential for the practical application. To date, most of (if not all) the SJDs are installed in an inter‐story scenario to mitigate the inter‐story drift of building structures. In such cases, the out‐of‐plane instability issue of the SJD is not pronounced since the size of the SJD is not quite large. As the demand of using SJDs in the large‐scale scenarios keeps increase, the out‐of‐plane instability of the SJD starts to draw attention. In view of this problem, a novel 3‐dimensional SJD (3D SJD) configuration is proposed in this study. The 3D SJD achieves better global stabilities, thus facilitates its application in some large‐scale scenarios. The mechanical models of the 3D SJD with different degrees of complexity are derived, and a simplified mechanical model is validated against finite element simulations. An example of the application of the 3D SJD is reported. The results prove, in a quantified way, that the 3D SJD is highly efficient for mitigating the structural seismic response in large‐dimensional scenarios, and the 3D SJD exhibits an elevated energy‐dissipation ability compared with the conventional damper arrangement.