Inelastic Displacement Ratios for Nonstructural Components Subjected to Floor Accelerations

This paper describes a study on the characterization of the Inelastic Displacement Ratios (IDRs) of inelastic acceleration-sensitive nonstructural components subjected to floor accelerations obtained from the linear analysis of multistory building structures under far-field ground accelerations. Several building models having different structural systems and a number of stories were considered. IDRs were obtained from the displacement response of elastic and inelastic single-degree-of-freedom systems subjected to floor accelerations. Similarities and differences between floor acceleration IDRs and ground acceleration IDRs were identified, and efforts were made to explain the differences. Finally, a predicting equation for floor acceleration IDRs is proposed and validated.     

宋代官员墓葬相关问题刍议

从现有考古材料来看,与前代相比,宋代墓葬体现的等级制度并不明显,而官员墓葬似恰是造成这一状况的原因.原本应当尊奉制度、为民表率的官员群体中,有很大一部分官员并未向下传递上层的丧葬文化,反而被出身之地或归葬之所的富裕平民阶层同化.由此使其地下墓葬部分呈现出“地方化”的特征.而这一情形,所反映的可能是两宋时期,民间经济力量...     

Study on Low-Frequency Characterizations of Pulse-Type Ground Motions through Multi-Resolution Analysis

This article makes an attempt to investigate the low-frequency characterizations of pulse-type ground motions through ground motion components instead of original records. A decomposed method based on multi-resolution analysis is introduced in this article. The accuracy and validity of the method is tested in frequency domain, time domain and dynamic response. A dataset of 398 low-frequency components is obtained after the decomposition of 91 typical pulse-type records. A probabilistic model to describe the proportion of low-frequency components in corresponding original ground motions is established. At last, the decomposed method is used to investigate the impulsive characterizations of pulse-type ground motions.     

A Multi-Mode Method for Estimation of Floor Response Spectra

A new simplified procedure for estimation of floor response spectra (FRS) is proposed. This methodology enriches the most common procedures using nonlinear response-history analysis to predict FRS by including a direct multi-mode technique to estimate FRS. A novel feature of the procedure is that the coupling effect is considered to establish equivalent modal systems and the FRS are developed by incorporating capacity spectrum method in conjunction with ductility-based FRS for each modal system. Both the proposed method and the traditional method are applied to three steel moment frame structures, and a reasonable accuracy is demonstrated.     

旅游功能系统:结构与要素分析

地理学将旅游作为人类活动的一种空间表现形式来研究,研究旅游活动的空间相互作用关系,是旅游地理学的重要内容。本文引入旅游功能系统这一概念,对其结构和要素进行了初步分析,并总结认为,旅游功能系统作为一种抽象描述旅游活动空间相互作用的概念,对旅游开发与规划具有指导意义。     

Variable Selection in Artefact Compositional Studies

In artefact compositional studies, the selection of variables to use in analysis is unavoidable. Given this ubiquity, surprisingly little attention has been paid to ways in which variables might be selected. After arguing the case for the importance of variable selection, two systematic approaches to making a choice, which have had little or no application in archaeometry, are discussed and illustrated. One, based on the use of principal components, is appropriate if structure in the data is not known. The other, based on the use of classification trees, is applicable when there are known or assumed groups in the data.     

Effect of Nonlinearity of Frame Buildings on Peak Horizontal Floor Acceleration

Using representative numerical models of eight code-designed steel moment-resisting frame buildings and several ground motions, time-history analyses are performed and a critical evaluation of Peak Horizontal Floor Acceleration (PHFA) demands is conducted. The frames are modeled alternatively as linear and nonlinear systems to isolate the effect of building nonlinearity on PHFA. In most cases, PHFA is reduced when nonlinear behavior of a building is considered; however, in some cases, significant amplification of PHFA is observed. Results from the numerical study provide insight into the trend of modal response modification factors presented taking ground motion spectral shape into account.     

‘The Darroch affair’: Assemblage lines,components, and transformations

This article examines the underresearched role of lines and components in recomposing geopolitical assemblages. It does so by focusing on a single body at the middle of an event to show how its lines of assembling conditioned wider transformations. The event in question – the leaking of confidential diplomatic materials in July 2019 as part of the so-called “Darroch Affair” – opened a massive rift between governing and bureaucratic arms of the UK state. Set in the context of ongoing struggles to recode the transatlantic diplomatic assemblage (TADA) by US and UK governments, Sir Kim Darroch, British Ambassador to the US, was at front and centre of the resulting leaks imbroglio. Using assemblage thinking, I offer an alternative conceptualisation of Darroch's body as distributed across the TADA via structurally complex lines of assembling. I argue the historical trajectories of these lines accelerated assemblage recompositions as the excessiveness of events led to Darroch's body occupying more and more possibility spaces across the TADA. The article considers how the linear complexity of Darroch's body arose, and the consequences of the resulting recompositions of the TADA for its nested diplomatic worlds.     

Analytical Study of Large-Area Suspended Ceilings

Due to the complex and heterogeneous construction of suspended ceiling systems, current standards provide only limited guidance for their seismic design. Simplified uniaxial numerical models of suspended ceiling systems are developed based on the experimental observation. Main runners with tributary ceiling area and grid connections in the longitudinal direction are modeled using lumped-masses and nonlinear connection springs. The proposed numerical models can be used as simple computational tools to explore the dynamic behavior and to estimate the design forces. Possible changes to the current standard design that suggest a more rational distribution of ceiling inertia forces are also discussed.     

Floor Spectra of Inelastic RC Frame Buildings Considering Ground Motion Characteristics

A range of reinforced concrete frame buildings with different levels of inelasticity as well as periods of vibration is analyzed to study the floor response. The derived floor acceleration response spectra are normalized by peak ground acceleration, peak floor acceleration, and ground response spectrum. The normalization with respect to ground response spectrum leads to the lowest coefficients of variation. Based on this observation as well as previous studies, an amplification function is proposed that can be used to develop design floor spectra from the ground motion spectrum, considering the building’s dynamic characteristics and level of inelasticity.