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A system‐level shake‐table test of a two‐story low‐damage concrete wall building was conducted in 2019. The test building consisted of unbonded post‐tensioned (UPT) walls with perimeter frames and different wall‐to‐floor connections to provide deformation compatibility. The test results highlighted that the measured lateral strength of the building notably exceeded the design value. This over‐strength was largely attributed to the compatibility deformations imposed on the floor systems. Previous simulation results from planar models also underestimated the building global response and lateral strength, so a modified model was developed to improve the accuracy by accounting for the system‐level interactions. The floor slab out‐of‐plane strength was assessed by the floor slab models using shell elements to quantify their response when subjected to deformations induced by the UPT wall uplift. In addition, the unintended effects of the beam‐to‐floor connection strength were also calculated. The strength contributions from the floor and connections were included in the planar frame models using lumped rotational springs located at the slotted‐beam joints. Lastly, the models were also updated to include flexibility in the connections of the energy dissipations at the wall bases based on test observations. Nonlinear time history analysis of the updated models for unidirectional loading cases demonstrated an improved calculation of the test results for both the global and local responses. When considering the floor interaction in the updated models, the absolute relative errors of peak overturning moments reduced from 35.4% to 15.6% averagely for the longitudinal direction, and from 23.1% to 14.1% averagely for the transverse direction. [ABSTRACT FROM AUTHOR]

Post-tensioning self-centering walls are a well-developed and resilient technology. However, despite extensive research, the application of this technology has previously been limited to low-rise buildings. A ten-story self-centering wall building has now been designed and constructed using the state-of-art design methodologies and construction detailing, as described in this paper. The building is designed in accordance with direct displacement-based design methodology, with modification of seismic demand due to relevant issues including higher-mode effects, second order effects, torsional effects, and flexural deformation of wall panels. Wall sections are designed with external energy-dissipating devices of steel dampers, and seismic performance of such designed self-centering walls is evaluated through numerical simulation. It is the first engineering project that uses self-centering walls in a high-rise building. The seismic design procedure of such a high-rise building, using self-centering wall structures, is comprehensively reviewed in this work, and additional proposals are put forward. Description of construction detailing, including slotted beams, flexible wall-to-floor connections, embedded beams, and damper installation, is provided. The demonstration project promotes the concept of seismic resilient structures and contributes to the most appealing city planning strategy of resilient cities at present. The paper could be a reference for industry engineers to promote the self-centering wall systems worldwide. [ABSTRACT FROM AUTHOR]

Simple Summary: What does not have a name is difficult to understand and protect. Upon the unexpected discovery of an Hynobius salamander in Fujian province, China, we worked on understanding its relationship with other species and ultimately describing it. Please welcome the Fujian Bamboo Salamander to science, a segregated species based on genetics and morphology. While it is related to other southern mainland Chinese species, it may have diverged earlier and share some similarities with morphology and behavior with the Anji salamander. The Fujian Bamboo Salamander is special as it produces vocalization when under threat. The species is, however, incredibly rare, fitting the definition of Critically Endangered in the IUCN Red List of Threatened Species. It is important to describe lineages before they go extinct, as we can only protect what we know. This is especially important in the case of microendemic species likely to be relict populations, such as Hynobius salamanders in southern China. Here, we unexpectedly sampled Hynobius individuals in Fujian province, China, and then worked on determining their taxonomic status. We describe Hynobius bambusicolus sp. nov. based on molecular and morphological data. The lineage is deeply divergent and clusters with the other southern Chinese Hynobius species based on the concatenated mtDNA gene fragments (>1500 bp), being the sister group to H. amjiensis based on the COI gene fragment, despite their geographic distance. In terms of morphology, the species can be identified through discrete characters enabling identification in the field by eye, an unusual convenience in Hynobius species. In addition, we noted some interesting life history traits in the species, such as vocalization and cannibalism. The species is likely to be incredibly rare, over a massively restricted distribution, fitting the definition of Critically Endangered following several lines of criteria and categories of the IUCN Red List of Threatened Species. [ABSTRACT FROM AUTHOR]

The severe damage of conventionally designed buildings and consequent socioeconomic impacts after major seismic events have spurred the development of self‐centering systems with high seismic resilience. Post‐tensioned (PT) walls with rocking interfaces allowed to open and close and unbonded PT bars that provide most of the re‐centering ability have been developed extensively as a promising self‐centering technology. Aiming at providing essential insights into the seismic performance of self‐centering tube systems, a 1/6‐scale ten‐story self‐centering tube building was designed, constructed, and tested on a shaking table subjected to a series of unidirectional and bidirectional ground motions with increasing intensities. The test building consisted of a self‐centering tube that included four PT walls and provided the primary lateral force resistance in both directions, a perimeter rocking frame that was designed mainly to carry gravity loads, and particular connections with slots to accommodate the potential displacement incompatibility among the PT walls and surrounding components. The experimental results indicated the excellent seismic performance of the test building that had reliable structural integrity and experienced only confined damage even when subjected to extremely high intensities. The building also exhibited satisfactory re‐centering ability with minimal residual deformations at the conclusion of testing. It was demonstrated that the self‐centering tube system is a desirable low‐damage alternative to traditional tube systems in earthquake‐prone regions. The benchmark data from this test provided unique suggestions and support for further research on the design methods, numerical modeling, and experimental testing of self‐centering tube systems. [ABSTRACT FROM AUTHOR]

The severe damage of conventionally designed buildings and consequent socioeconomic impacts after major seismic events have spurred the development of self‐centering systems with high seismic resilience. Post‐tensioned (PT) walls with rocking interfaces allowed to open and close and unbonded PT bars that provide most of the re‐centering ability have been developed extensively as a promising self‐centering technology. Aiming at providing essential insights into the seismic performance of self‐centering tube systems, a 1/6‐scale ten‐story self‐centering tube building was designed, constructed, and tested on a shaking table subjected to a series of unidirectional and bidirectional ground motions with increasing intensities. The test building consisted of a self‐centering tube that included four PT walls and provided the primary lateral force resistance in both directions, a perimeter rocking frame that was designed mainly to carry gravity loads, and particular connections with slots to accommodate the potential displacement incompatibility among the PT walls and surrounding components. The experimental results indicated the excellent seismic performance of the test building that had reliable structural integrity and experienced only confined damage even when subjected to extremely high intensities. The building also exhibited satisfactory re‐centering ability with minimal residual deformations at the conclusion of testing. It was demonstrated that the self‐centering tube system is a desirable low‐damage alternative to traditional tube systems in earthquake‐prone regions. The benchmark data from this test provided unique suggestions and support for further research on the design methods, numerical modeling, and experimental testing of self‐centering tube systems. [ABSTRACT FROM AUTHOR]

Purpose: To provide a comprehensive investigation of the optical quality across the visual field for current mainstream types of refractive surgeries. Methods: Sixty eyes from 60 adults who received refractive surgery of either femtosecond laser–assisted laser in situ keratomileusis (FS-LASIK), Q-value guided customized laser in situ keratomileusis (Q-LASIK), small incision lenticule extraction (SMILE), or Implantable Collamer Lens (ICL) (STAAR Surgical) implantation were included in this study. Refraction and optical aberrations from a visual field of horizontal 60° (from temporal 30° to nasal 30°) and vertical 36° (from superior 20° to inferior 16°) were measured using a custom-made Hartmann-Shack wavefront peripheral sensor. Refractive error, higher order aberrations, point spread function (PSF), and Strehl ratio were compared among these groups prior to and after the surgical procedures, respectively. Results: All types of surgical procedures achieved an almost plano refraction in the central retina. This was also the case in the peripheral retina for the three types of laser refractive surgeries. However, residual peripheral relative hyperopic defocus was observed after ICL implantation. In all groups prior to the surgery, PSFs showed increasing distortion with eccentricity and arrow-like shape pointing toward the central fovea in the periphery in diagonals. Degradation of the PSFs was diminished by all three types of laser refractive surgeries, whereas ICL implantation made the peripheral distortion more prominent. Conclusions: Although ICL implantation produced a similar impact on refractive correction and objective optical quality in the central vision compared with other laser refractive surgeries, its outcome on the peripheral optics is different. The impact of this difference on visual performance deserves notice and warrants further investigation. [J Refract Surg. 2023;39(1):40–47.] [ABSTRACT FROM AUTHOR]

Summary: To support the development of low‐damage concrete structures, a system‐level shake‐table test of a two‐story concrete wall building implementing state‐of‐the‐art design concepts was conducted using the multi‐functional shake‐table array at Tongji University as part of an international collaborative project. The test building was designed with a perimeter frame and exterior post‐tensioned concrete walls in both directions. Different floor systems and wall‐to‐floor connections were incorporated in the test building to compare a number of design concepts and construction details. A range of energy dissipation devices were installed at the wall base and/or slotted‐beam joints of the test building. To simulate the test building response during the shake‐table tests, numerical models of the test building in both the longitudinal and transverse directions were established in OpenSees. Because the test building utilized flexible and isolated wall‐to‐floor connections that specifically reduced potential wall‐to‐floor interaction, planar frame numerical models were selected to represent the test building in each direction of loading. In the models, fiber hinge elements were used to simulate the unbonded post‐tensioned walls and a modified multi‐truss spring method was adopted to simulate the slotted‐beam joints with and without dampers. Inelastic time‐history analyses of the numerical models were conducted considering three earthquake intensities and comparisons of the test and simulation responses of the building are presented. The simulation results showed that the analytical model established in this study could reasonably predict both the global and local responses of the test building under different shaking intensities. [ABSTRACT FROM AUTHOR]

A shake-table test of a 2-story full-scale low-damage concrete wall building was conducted on the multifunctional shake-table array at Tongji University to validate the system-level dynamic response of this type of building. The test building implemented state-of-art low-damage structural systems, including post-tensioned (PT) precast concrete walls, precast concrete frames with slotted beam connections, and a variety of energy-dissipating devices. The building was subjected to 39 separate earthquake tests, consisting of a range of structural design configurations and ground motions including different intensity records, far-field and near-fault records, and short- and long-duration records. The test data and documentation recorded throughout the project have provided a significant high-quality data set for improving understanding both global and local response of post-tensioning concrete wall buildings. The data set has been published and is publicly available. The methodology of the test documentation and data collection for each stage of the project are described, and a road map for navigating the archived data set is provided to support its future use. [ABSTRACT FROM AUTHOR]

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 low‐damage structural system that have been implemented in a range of buildings. In order to provide essential evidence to support the development of low‐damage 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. [ABSTRACT FROM AUTHOR]

A series of reinforced concrete wall tests were conducted at the University of Auckland to address the lack of experimental data on flexure-dominant lightly reinforced concrete walls that are common in multistorey buildings in regions of low or moderate seismicity. The experimental program comprised 11 rectangular reinforced concrete walls that were subjected to pseudo-static cyclic loading. The tests were used to investigate minimum vertical reinforcement provisions for reinforced concrete walls and formed the basis for revisions to the New Zealand Concrete Structures Standard NZS 3101 and the US Building Code Requirements for Structural Concrete ACI 318. The recorded documentation and data collected throughout the test program have provided a high-quality dataset that is a valuable resource to researchers investigating the seismic behavior of reinforced concrete walls. The dataset is published and publicly available on DesignSafe-CI with the project number PRJ-1648. The methodology of the data collection is described, and a road map for navigating the dataset is presented to support future use of the archived dataset. [ABSTRACT FROM AUTHOR]

Previous studies showed improved seismic performance of reinforced concrete (RC) plane frames by adding RC braces. However, in literature, the studies on the efficiency of RC braces for the improvement of seismic performance of RC space frame (RCSF) are very limited. This paper presents the experimental results on two 1/4-scale, two-storey and three-bay RCSFs under cyclic loading, i.e. a control RCSF and another RC X-braces strengthened RCSF (termed as CBRCSF). The test results show that compared with the control frame, the seismic performance of the CBRCSF was improved significantly in terms of lateral strength, stiffness degradation and energy dissipation capacity due to the addition of RC X-braces. Moreover, the CBRCSF could continue to bear loads after the rupture of the RC braces, thereby revealing redundancy of the CBRCSF because of the use of RC X-braces. [ABSTRACT FROM AUTHOR]

Reinforced concrete members in structures are typically subjected to a combination of bending, shear and axial compression (tension) loads. A simplified bending-shear-axial compression (tension) interaction formula based on bending-axial compression, bending-shear and bending-axial tension interactions was proposed to obtain the strength envelope of symmetrically reinforced concrete members under bending, shear and axial compression (tension). The interaction formula is verified by a comparison with experimental data. A sample planar-frame calculation result indicates that the envelope can be used as a failure criterion in symmetrically reinforced components to determine the safety of the members and calculate the residual capacities of components under bending, shear and axial compression (tension). [ABSTRACT FROM AUTHOR]

The article presents the author's views on a research conducted by Ari Wibowo and colleagues, which was focused on analyzing the seismic performance of the lightly reinforced structural walls used in the architectural designs. The research was conducted by calculating the aspect ratios of the wall as it will help in identifying the flexure behavior of the crack in the base of the wall.