Seismic Performance to Emergency Centers,Communication and Hospital Facilities Subjected to Nepal Earthquakes, 2015

Emergency centers, communication systems, and hospitals are essential infrastructures for emergency rescue and subsequent reconstruction activities. An investigation into the Nepal 2015 earthquake sequences found that the visited government offices were functioning normally 40 days after the main shock; that the local media failed to coordinate with the entire society at the beginning, but mobile phone-based communication recovered quickly; and that the hospitals in high-intensity areas were badly damaged as a result of improper design and adverse site configuration. Recommendations are proposed to enhance the aseismic capacity of structural and non-structural components using earthquake early warning and base isolation.     

An XFEM Model for Seismic Activity in Indian Plate

Empirical approaches based on the available earthquake catalog are popular among engineers to estimate seismic hazard. The seismic activity on individual faults inferred from these approaches is associated with a large number of uncertainties, especially due to lack of data. This article proposes a mechanistic approach to quantify seismic and fault activity, thereby overcoming the difficulties in the existing empirical procedure. A finite element (FE) model for Indian Plate, with the geological ‘cratons’ is developed and subject to plate driving forces namely, the ridge push and the slab pull forces. The material properties and the thickness of both plate and cratons are obtained through inversion using the recently available Global Positioning System (GPS) data. The tectonic faults are modeled using the well-known ‘extended FE method (XFEM)’. The simulated strains at fault level are compared with the computed strain rates from the earthquake catalog. Further, the procedure to quantify fault activity is demonstrated for Gujarat, India.     

Scalar Structure-Specific Ground Motion Intensity Measures for Assessing the Seismic Performance of Structures: A Review

The assessment of the seismic performance depends on the choice of the earthquake Intensity Measure (IM). During the past years many IMs, which take into account not only earthquake characteristics but also structural information, have been proposed. However, no consensus on which IM is the best predictor of the seismic response exists. Along these lines, the objective of this paper is to present the various developed scalar structure-specific seismic IMs and the problems associated with their use in practice, so that the engineer may become familiar with them and their implications in the context of Performance-Based Earthquake Engineering.     

Learning by ‘design’: how undergraduates in Singapore learn to become engineers

ABSTRACT

In this paper, we explore the evolving norms and dispositions of creativity and enterprise of engineering students using data gathered from a newly established technology and engineering-focused university called ‘UniTech’ located in Singapore. Based on interviews with students, we seek to explain (1) what they learn, reject, adopt and appropriate; (2) the kinds of challenges they face and (3) the unexpected and serendipitous outcomes of their learning. Through an integrated engineering curriculum focusing on design, students learn to be technically competent, creative and entrepreneurial persons. This paper considers how the curriculum works as a set of formal procedures preparing students for a future ‘knowledge-based economy’ imagined to be technology-intensive, dynamic and filled with opportunities but also increasingly uncertain. We analyse how students at UniTech negotiate this design-focused curriculum where experiences of creativity, open-ended possibilities and holistic perspectives intersect with the national economic agenda of a knowledge-based economy.     

Alternative Radio: exhibiting radio and music heritage after the Christchurch earthquakes

This article examines the representation of Christchurch, New Zealand, student radio station RDU in the exhibition Alternative Radio at the Canterbury Museum in 2016. With the intention of ‘making visible what is invisible’ about radio broadcasting, the exhibition articulated RDU as a point of interconnection between the technical elements of broadcasting, the social and musical culture of station staff and volunteers, and the broader local and national music scenes. This paper is grounded in observations of the exhibitions and associated public programmes, and interviews with the key participants in the exhibition including the museum’s exhibition manager and staff from RDU, who acted as independent practitioners in collaboration with the museum. Alternative Radio also addressed the aftermath of the major earthquake of 22 February 2011, when RDU moved into a customised horse truck after losing its broadcast studio. The exhibition came about because of the cultural resonance of the post-quake story, but also emphasised the long history of the station before that event, and located this small student radio station in the broader heritage discourse of the Canterbury museum, activating the historical, cultural, and personal memories of the station’s participants and audiences.     

Single-Degree-of-Freedom Characterization of Multi-Phase Passive Control Systems

A Multi-phase Passive Control System (MPCS) combines two passive control devices in order to offset the individual weaknesses and enhance structural performance, allowing the structure to respond effectively to varying levels of loading. Previous work involving a nine-story frame demonstrated the effectiveness of MPCSs but the fundamental understanding of the system was lacking. In order to more clearly understand the behavior and identify important parameters and parameter interactions, a single-degree-of-freedom (SDOF) non-linear dynamic study was performed. The results offer significant insight towards developing structural systems adaptable to multi-objective performance-based design procedures that meet higher performance standards than for ductility-based design.     

人类基因工程面临的道德问题

基因工程已经用于人类克隆并因此引起了极大的关注和争议。比如道德灾难、基因歧视以及转基因产品的不确定性。因此人类克隆应该受到限制,用于治疗目的的人类克隆应该严格受控。     

Fuzzy-Sliding-Mode Supervisory Control of a Seismic Shake Table with Variable Payload for Robust and Precise Acceleration Tracking

Precise tracking of the earthquake acceleration profile in the presence of uncertainties is a challenge for the shake table control design. Design and implementation of a fuzzy-sliding-mode super- visory controller for an electric seismic shake table with variable payload is addressed in this paper. The proposed controller contains two layers including a proportional–integral loop and a fuzzy-sliding-mode supervisory controller. The controller is then implemented in the shake table and its performance is evaluated. The test results reveal successful performance of the proposed controller at robust tracking of some harmonic and seismic excitations in the presence of parametric uncertainties.     

SYSTEM IDENTIFICATION OF LANDFILL SEISMIC RESPONSE

Assessment of landfill seismic response necessitates the availability of reliable dynamic material properties. During the past decade, geophysical surveys and computational studies have been conducted to investigate the seismic response of the Operating Industries, Inc. (OII) landfill in Southern California. In this paper, a survey and summary of available research results is presented. In addition, a set of Oil input-output seismic records during six earthquakes is thoroughly analysed. Spectral analyses are conducted to shed light on the landfill dynamic response characteristics. A simple shear beam model is found to be useful in modelling the landfill resonant behaviour. System identification techniques are employed to estimate the landfill stiffness and damping properties. These properties are defined by minimising the difference between computed and recorded acceleration response spectra at the landfill top. The identified stiffness properties are found to be near the lower bound of those documented through geophysical measure-ments. Identified damping of about 5% (at resonance) is within the range of earlier investigations. Comparisons of the computed and recorded accelerations show: (I) effectiveness of a linear viscous shear beam model in simulating the landfill dynamic behaviour, for the recorded small to moderate levels of dynamic excitation (up to 0.26 g peak lateral acceleration), and (ii) potential of the employed system identification procedure for analysis of input-output seismic motions.