Vertical dynamic interactions of poroelastic soils and embedded piles considering the effects of pile-soil radial deformations

The paper presents an analytical solution for the vertical dynamic interaction analysis of a poroelastic soil layer and an embedded pile with the consideration of pile-soil radial deformations. The soil is treated a three-dimensional porous continuum and described by the Boer’s poroelastic model, while the pile is treated as a two-dimensional rod with both radial and vertical deformations of which the equation of motion is derived by the Hamilton’s variational principle. Without the introduction of potential functions, first take the volumetric strain of soil skeleton and pore fluid pressure as intermediate variables to deal with the equations of motion for the soil and then use the separation of variables to solve the equations of motion for the soil and the pile. By imposing the boundary and continuity conditions of the pile-soil system, the dynamic impedance in frequency domain and the velocity response in time domain of the pile top are obtained. The present solution is then verified by comparing with the corresponding finite element model computation results and the existing solutions. The effects of the pile-soil parameters on the dynamic characteristic of the pile-soil system are also analyzed. Some significant conclusions are drawn, which can provide useful reference for related engineering practice.     

冒险游戏场的起源、实例与启示

游戏是儿童成长中不可或缺的部分,儿童友好城市的重要硬件措施是建设儿童游戏据点。冒险游戏场作为代表性场所,在治愈儿童心理问题、培养儿童责任感、激发儿童危机意识和自我保护技能等方面发挥了重要作用。冒险游戏场在国外已有70余年的实践历史,但我国对冒险游戏场的研究尚处于初级阶段,在实践方面仍属空白。本文从剖析冒险游戏场的起源与核心思想入手,重点围绕欧美和日本的发展背景,对其发展历史进行系统梳理,再深入解读"常设"和"非常设"的三个典型案例,总结出设计理念"自由化"、空间要素"自然化"、场所运营"专业化"三个关键启示,为我国儿童公共空间的研究提供借鉴和参考。     

Response of Aspergillus flavus,Aspergillus niger and Penicillium citrinum to oxidative stress induced by Fenton’s reagent

The presence of fungi in water systems represents a threat to human health. Hydrogen peroxide is known for its disinfecting properties and easy decomposition to water and oxygen. Its activity can be enhanced by the addition of iron as a catalyst, a reagent known as Fenton?s reagent. In the present study, different Fenton concentrations were investigated on the spores of Aspergillus flavus, Aspergillus niger and Penicillium citrinum at different time intervals. The results indicate that complete inactivation of spores was noticed after 60 min of exposure to both 2 and 3% H₂O₂ catalyzed by 0.025 g Fe²⁺/100 ml for A. niger, and 3% H₂O₂ catalysed by 0.075 g Fe²⁺/100 ml for P. citrinum. The activity of two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), was determined in mycelial mat harvested after 7 days. Their activities were either highly increased or reached their minimum values prior to inactivation of spores.     

Estimation of life vulnerability inside buildings during earthquakes

A methodology is presented for assessing the expected loss of human lives due to the structural damage, failure of contents and non-structural components inside buildings during earthquakes. This approach estimates human life losses considering whether the structure collapses (partial or totally) or not. Entrapment and entrapment fatality rates are calculated using available data from worldwide literature and newspapers of 50 collapsed buildings, which information is reasonably reliable. We apply this methodology to one example of a five-floor RC frame building of typical office occupancy. Vulnerability functions are presented relating the intensity of the earthquake to the loss of human lives inside buildings, considering different times of occurrence of the earthquakes: daytime, commuting time and nighttime. Uncertainties in all parts of the process are very large, but they are formally addressed and taken into account. This methodology may improve the risk assessment for insurances purposes, optimisation of the cycle of life, mitigation strategies, risk control and tolerable risk.     

An Examination of Tabriz Gardens in Iranian Garden Art

This study was conducted to determine the place of historic gardens in the city of Tabriz vis-a-vis Iranian garden arts. It provides information on the historic gardens of Tabriz, which are no longer in existence, for example, ‘Saheb Abad’ Garden, ‘North’ Garden, ‘Sefa’ Garden, ‘Amir Kabir’ Garden, ‘Saheb Divan’Garden and ‘Fath Abad’ Garden, as well as four historical maps belonging to the Qajar era in the city of Tabriz. In this research, the factors influencing the design of El-Goli Garden were studied, which can be grouped into three major categories: physical, biological and cultural. After a brief study of the above factors in the city of Tabriz and its different microclimates, the types of similarities that exist relating to Iranian garden art were determined.     

Algorithmic Tectonics: How Cold War Era Research Shaped Our Imagination of Design

Between 1959 and 1967, the Massachusetts Institute of Technology (MIT) hosted the pioneering Computer-Aided Design Project, funded by the US Air Force. Engineers, researchers and students were brought together to re-imagine ‘design in the language of the machine’, and one of the most renowned students on this programme was Ivan Sutherland, the inventor and programmer of Sketchpad - the first interactive graphics system. Here, Daniel Cardoso Llach , an architect and researcher based at MIT, traces the influence of this Cold War project on the culture of building design and production today.     

Dragons Adrift: The New Chinese Landscape

The work of New York-based artist Nancy Wolf is preoccupied with the relationship between people and the contemporary city. Here she explains how a meeting with scholar and poet Lap Lam in Hong Kong provided much of the inspiration for her work in China, which she describes as ‘a commentary on the enormous changes in today's Chinese landscape created by Modernist architecture and urban planning’.     

All Night Long: The Architectural Jazz of the Texas Rangers

In the mid-1950s, a group of young faculty at the University of Texas School of Architecture in Austin - aka the Texas Rangers - entertained themselves with weekly sessions of a sophisticated, collective drawing game, ‘Dot-the-Dot’, in which there was an emphasis on inventive fluency in hand drawing as well as an innate knowledge of historic European city plans. What happened when Mark Morris , Visiting Associate Professor at Cornell University, decided in a design studio to ask present-day students to revive the game?     

An Architecture of Exception: Transgressing the Everyday – Superflex's Flooded McDonald's

In Flooded McDonald's, a film by Danish artists' collective Superflex, the familiar sight of the fast-food restaurant is replaced by ‘a slowly emerging apocalyptical composition’, as the interior floods, objects are displaced and the retail space fills with water. Jonathan Mosley describes how this destabilised and other disaster-invoked visions of architecture – structures and spaces breaking down – enable us to use our imagination to test the parameters of the everyday.     

Natural Methods of Interaction Or Natural Interaction in the Everyday Digital World

Computers, mobiles and automatised machines are so omnipresent that the means by which we interact with digital devices is now generally regarded as a given. Italian practice iO Agency, though, questions our use of mechanised interfaces and the language that they require us to learn. Valentina Croci explains how iO Agency has developed more natural ways for people to interact with digital environments through physical or tactile ‘triggers’. Copyright © 2008 John Wiley & Sons, Ltd.