ANALYTICAL SEISMIC FRAGILITY CURVES FOR SKEWED MULTI-SPAN STEEL GIRDER BRIDGES

Most of the past seismic fragility studies on typical highway bridges in the Central and Southeastern United States (CSUS) have focused on regular multi-span bridges with little to no skew. However, past earthquakes and studies have shown that skewed multi-span simply supported bridges may also be susceptible to earthquake damage, specifically causing coupled responses (longitudinal and transverse) that place more demand on individual components. With over 27 percent of simply supported steel girder highway bridges in the CSUS having a skew angle over 15 degrees, there is a specific need to further quantify the vulnerability of such bridges exposed to seismic hazard. This study seeks to add to the current knowledge base of the seismic fragility of multi-span steel girder bridges in the CSUS by specifically addressing the issue of skew in the assessment. A sensitivity study of a three span bridge for each of the column, abutment, and bearing components along with the system as a function of skew angle is presented. This comparison indicates that bridge vulnerability appears to be largely unaffected by skew angles under 30 degrees, but larger skew angles do indeed result in more fragile bridge systems. Within this system the longitudinal components of the bridge become less fragile with increasing skew, but to a lesser degree than the transverse components becoming more fragile. Understanding the impact skew plays on seismic bridge fragilities will facilitate more robust regional risk analyses of highway systems. Another aspect of this study is a presentation of seismic fragility curves developed for skewed multi-span simply supported steel girder bridges. The fragility curves indicate that for skew angles les than thirty degrees bridge fragility is not significantly affected. Larger skew angles result in a more fragile system in relation to increasing skew values. A comparison between the number of spans and system fragility results in a significant decrease in system fragility with an increase in the number of spans. The implications of the effects of skew angle and the number of spans will greatly contribute to regional risk assessment procedures such as those presented by HAZUS-MH

Family Resources Survey: United Kingdom 2010/11

The Family Resources Survey collects information on the incomes and circumstances of private households in the United Kingdom. It has been running since October 1992. This report summarises the results for the 2010/11 full survey year in which approximately 25,000 households were interviewed. The report is divided into sections covering: Income and State Support Receipt; Tenure; Savings and Investments; Disability; Carers; Occupation and Employment; and Pension Participation

CAADP at 10 - Water is a Missing Link in the Southern African Development Community

Water has a low profile in Comprehensive Africa Agriculture Development Programme (CAADP) processes in the Southern African Development Community (SADC), presenting an opportunity to develop stronger ties between the agriculture and water sectors in the region

Benchmarks for double Higgs production in the singlet-extended standard model at the LHC

The simplest extension of the standard model is to add a gauge singlet scalar, S: the singlet-extended standard model. In the absence of a Z2 symmetry S→−S and if the new scalar is sufficiently heavy, this model can lead to resonant double Higgs production, significantly increasing the production rate over the standard model prediction. While searches for this signal are being performed, it is important to have benchmark points and models with which to compare the experimental results. In this paper we determine these benchmarks by maximizing the double Higgs production rate at the LHC in the singlet-extended standard model. We find that, within current constraints, the branching ratio of the new scalar into two standard model–like Higgs bosons can be upwards of 0.76, and the double Higgs rate can be increased upwards of 30 times the standard model prediction

The Lived Experiences of Chinese International Students Preparing for the University-To-Work Transition: A Phenomenological Qualitative Study

Chinese international students have been the largest growing number of international students on U.S. college and university campuses for the last ten years. However, there is minimal research literature that pertains to Chinese international students’ experiences on U.S. campuses and currently no research literature that reflects the entirety of their experience studying in the U.S. The purpose of thisphenomenological qualitative study was to give a voice to Chinese international students who are preparing for the university-to-work transition to better understand their experiences as international students in the United States, specifically the types of transitional stressors they experienced and how they coped with these stressors. Five major themes and the essence of the participants emerged from the data analysis and are presented, discussed, and implication for campus based mental health professionals are provided

Searching for Dark Photons with Maverick Top Partners

In this paper, we present a model in which an up-type vector-like quark (VLQ) is charged under a new $U(1)_d$ gauge force which kinetically mixes with the SM hypercharge. The gauge boson of the $U(1)_d$ is the dark photon, $\gamma_d$. Traditional searches for VLQs rely on decays into Standard Model electroweak bosons $W,Z$ or Higgs. However, since no evidence for VLQs has been found at the Large Hadron Collider (LHC), it is imperative to search for other novel signatures of VLQs beyond their traditional decays. As we will show, if the dark photon is much less massive than the Standard Model electroweak sector, $M_{\gamma_d}\ll M_Z$, for the large majority of the allowed parameter space the VLQ predominately decays into the dark photon and the dark Higgs that breaks the $U(1)_d$ . That is, this VLQ is a `maverick top partner' with nontraditional decays. One of the appeals of this scenario is that pair production of the VLQ at the LHC occurs through the strong force and the rate is determined by the gauge structure. Hence, the production of the dark photon at the LHC only depends on the strong force and is largely independent of the small kinetic mixing with hypercharge. This scenario provides a robust framework to search for a light dark sector via searches for heavy colored particles at the LHC.Comment: 40 pages and 11 figure