Precast concrete facilitates a construction method using durable and rapidly erectable prefabricated members to create costeffective and high-quality structures. In this method, the connections between the precast members as well as between the members and the foundation require special attention to ensure good seismic performance. Extensive research conducted since the 1980s has led to new precast concrete structural systems, designs, details, and techniques that are particularly suited for use in regions of high seismic hazard. This paper reviews the state of the art of these advances, including code developments and practical applications, related to four different systems: (1) moment frames; (2) structural walls; (3) floor diaphragms; and (4) bridges. It is concluded from this review that the widespread use of precast concrete in seismic regions is feasible today and that the jointed connection innovation introduced through precast research leads to improved seismic performance of building and bridge structures.dividual papers. This paper is part of the Journal of Structural Engineering, © ASCE, ISSN 0733-9445. © ASCE 03118001-1 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-2 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-3 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-4 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-5 J. Struct. Eng. © ASCE 03118001-10 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-11 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18. Copyright ASCE. For personal use only; all rights reserved. © ASCE 03118001-18 J. Struct. Eng. J. Struct. Eng., 2018, 144(4): 03118001 Downloaded from ascelibrary.org by University of Notre Dame on 01/17/18.

SummaryAn innovative seismic resisting system consisting of a Precast Wall with End Columns (or PreWEC) has been developed, and its performance has been verified using large‐scale cyclic testing. The wall and end columns in the PreWEC system are anchored individually to a foundation using unbonded post‐tensioning. A newly designed, low‐cost mild steel connector is used to connect the wall and end columns horizontally along the vertical joint. The connectors are easily replaceable and provide additional hysteretic energy dissipation to the system. The PreWEC system can be economically designed to have a lateral load carrying capacity similar to that of a comparable reinforced concrete wall, while minimizing damage and providing self‐centering capability. In addition to confirming these benefits, the large‐scale test demonstrated that the PreWEC system: (i) would provide superior seismic performance compared to other currently available structural wall systems especially for the precast industry; and (ii) meets all the mandatory acceptance criteria established by the American Concrete Institute (ACI) for special unbonded post‐tensioned precast structural walls and building frame special reinforced concrete shear wall systems, as defined in the American Concrete Society of Civil Engineers (ASCE) 7‐05. Copyright © 2015 John Wiley & Sons, Ltd.

A series of cyclic lateral-load tests were conducted on four different unbonded post-tensioned precast concrete wall systems, including two Single Rocking Walls (SRW) and two PREcast Wall with End Columns (PreWEC). The main purpose of these tests was to systematically investigate the cyclic response of post-tensioned concrete walls with varying amounts of supplemental damping while keeping the initial post-tensioning force, wall dimensions, and confinement details constant. A secondary objective was to validate the wall panel design including the appropriate selection of axial force ratio and design of confinement and armouring details. All of the test walls exhibited excellent performance with uplift and rocking at the wall base with only minor damage observed, consisting of small amounts of spalling in the wall toes. There were consistent observations and measurements of the wall damage, concrete compressive strains, and wall neutral axis depths for both the SRW and PreWEC systems with the same wall panel dimensions. Based on these observations it is concluded that the behaviour of the wall panel in a PreWEC system is independent of the number of energy dissipating O-connectors. The O-connectors increased the hysteretic energy dissipation in the wall system and provided between 1.1-1.4% of additional equivalent viscous damping per connector for the PreWEC walls tested. Overall, the behaviour of the four walls tested confirmed the design procedures used, with both the global force-displacement response and local response parameters predicted with sufficient accuracy using an existing simplified analysis method.

All patients had trigger points in the vastus and gastrocnemius muscles, and 92% of patients experienced significant pain relief with trigger point injections at the first visit, indicating that a significant proportion of the OA knee pain was myofascial in origin. Further investigation is warranted to determine the prevalence of myofascial pain and whether treatment delays or prevents TKA.

Objective The minority stress model and much research based upon it tend to adopt and reinforce a deficit‐based approach. This study created and initially validated the minority strengths model, which by contrast outlines how personal and collective strengths in minority populations create resilience and positive mental and physical health. Materials and Method A sample of 317 lesbian, gay, bisexual, transgender, and queer individuals from diverse racial/ethnic backgrounds completed a national online survey. Results A minority strengths path model was generated with statistically significant paths and good fit indices, including all possible significant indirect effects. The model explained 16.8% of the variance in identity pride, 19.7% in self‐esteem, 32.9% in resilience, 41.6% in mental health, and 13.0% in positive health behaviors. Conclusions The minority strengths model holds promise to stimulate research on the personal and collective strengths of minority populations and the ways in which strengths generate resilience and positive mental and physical health.

The 2010–2011 Canterbury earthquakes in New Zealand revealed (1) improved structural response resulting from historical design advancements, (2) poor structural performance due to previously identified shortcomings that had been insufficiently addressed in design practice, and (3) new deficiencies that were not previously recognized because of premature failure resulting from other design flaws. This paper summarizes damage to concrete walls observed in the February 2011 Christchurch earthquake, proposes links between the observed response and specific design concerns, and offers suggestions for improving seismic design of walls in the following areas: amount of longitudinal reinforcement in wall end regions, suitable wall thickness to minimize the potential for out-of-plane buckling, and minimum vertical reinforcement requirements.

Background No trials have tested multifaceted mental health interventions recommended by public health organisations during COVID-19. The objective of this trial was to evaluate the effect of the Scleroderma Patient-centered Intervention Network COVID-19 Home-isolation Activities Together (SPIN-CHAT) Program on anxiety symptoms and other mental health outcomes among people vulnerable during COVID-19 owing to a pre-existing medical condition. Methods The SPIN-CHAT Trial was a pragmatic, two-arm, parallel, partially nested, randomised, controlled trial (1:1 allocation to intervention or waitlist). Eligible participants with systemic sclerosis were recruited from the international SPIN COVID-19 Cohort. SPIN COVID-19 Cohort participants were eligible for the trial if they completed baseline measures and had at least mild anxiety symptoms, had not tested positive for COVID-19, and were not currently receiving mental health counselling. SPIN-CHAT is a 4-week (3 sessions per week) videoconference-based group intervention that provided education and practice with mental health coping strategies, and provided social support to reduce isolation. Groups included 6–10 participants. The primary outcome analysed in the intention-to-treat population was anxiety symptoms (PROMIS Anxiety 4a version 1.0) immediately post-intervention. This trial is registered with ClinicalTrials.gov , NCT04335279 and is complete. Findings Of participants who completed baseline measures between April 9, 2020, and April 27, 2020, 560 participants were eligible and 172 participants were randomly assigned to intervention (n=86) or waitlist (n=86). Mean age was 55·0 years (SD 11·4 years), 162 (94%) were women, and 136 (79%) identified as White. In intention-to-treat analyses, the intervention did not significantly reduce anxiety symptoms post-intervention (−1·57 points, 95% CI −3·59 to 0·45; standardised mean difference [SMD] −0·22 points) but reduced symptoms 6 weeks later (−2·36 points, 95% CI −4·56 to −0·16; SMD −0·31). Depression symptoms were significantly lower 6 weeks post-intervention (−1·64 points, 95% CI −2·91 to −0·37; SMD −0·31); no other secondary outcomes were significant. No adverse events were reported. Interpretation The intervention did not significantly improve anxiety symptoms or other mental health outcomes post-intervention. However, anxiety and depression symptoms were significantly lower 6 weeks later, potentially capturing the time it took for new skills and social support between intervention participants to affect mental health. Multi-faceted interventions such as SPIN-CHAT have potential to address mental health needs in vulnerable groups during COVID-19, yet uncertainty remains about effectiveness. Funding Canadian Institutes of Health Research (CIHR; VR4-172745, MS1-173066); McGill Interdisciplinary Initiative in Infection and Immunity Eme...

The increasing need to reduce damage and downtime in modern buildings has led to the development of a low-damage design philosophy, where the earthquake loads can be resisted with damage confined to easily replaceable components. Post-tensioned (PT) concrete walls have emerged as a popular lowdamage structural system that have been implemented in a range of buildings. In order to provide essential evidence to support the development of lowdamage concrete structures, a system-level shake-table test was conducted on a two-storey low-damage concrete wall building implementing state-of-art design concepts. The test building included PT rocking walls that provide the primary lateral-load resistance in both directions, a frame that utilized slotted beam connections, and a range of alternative energy dissipation devices that were installed at wall base or/and beam-column joints. The building was subjected to 39 tests with a range of intensity ground motions, incorporating both unidirectional and bidirectional ground motions on the structure with different combinations of wall strength and energy dissipating devices. The building performed exceptionally well during the intense series of tests, confirming the suitability of both the design methods and the connection detailing implemented. The building achieved an immediate occupancy performance objective even when subjected to maximum considered earthquake hazard shaking. The building exhibited only minor damage at the conclusion of testing, with distributed cracking in the floors and cosmetic spalling in the wall toes that did not compromise structural capacity or integrity and could be easily repaired with minimal disruption.The test has provided a rich dataset that is available for further analysis of the building response and validation of design methods and numerical models.