Floor Motion Research Articles

A novel control strategy for reproducing the floor motions of high-rise buildings by earthquake-simulating shake tables

To enable the experimental assessment of the seismic performance of full-scale nonstructural elements with multiple engineering parameters (EDPs), a three-layer testbed named Nonstructural Element Simulator on Shake Table (NEST) has been developed. The testbed consists of three consecutive floors of steel structure. The bottom two floors provide a space to accommodate a full-scale room. To fully explore the flexibility of NEST, we propose a novel control strategy to generate the required shake table input time histories for the testbed to track the target floor motions of the buildings of interest with high accuracy. The control strategy contains two parts: an inverse dynamic compensation via simulation of feedback control systems (IDCS) algorithm and an offline iteration procedure based on a refined nonlinear numerical model of the testbed. The key aspects of the control strategy were introduced in this paper. Experimental tests were conducted to simulate the seismic responses of a full-scale office room on the 21st floor of a 42-story high-rise building. The test results show that the proposed control strategy can reproduce the target floor motions of the building of interest with less than 20% errors within the specified frequency range.

Experimental study on rocking blocks subjected to bidirectional ground and floor motions via shaking table tests

AbstractTo provide an insight for reliable seismic risk assessment of small building contents, the rocking response of freestanding wooden blocks subjected to 11 bidirectional horizontal ground motion records scaled to various intensity levels is investigated via shaking table tests. Three prisms and three cylinders with slenderness ratios of 2, 3 and 4, and three prisms having the same slenderness ratio of 3 but different size parameters of 158 mm, 237 mm and 316 mm, are considered. The peak ground acceleration statistics corresponding to rocking and overturning of the blocks are obtained. Shaking table tests to investigate the rocking response of the prisms located on different floors of a full‐scale three‐story reinforced concrete frame structure were also conducted. Experimental fragility curves corresponding to rocking and overturning occurrence of the blocks are finally generated. The experimental results highlight that the minimum rocking accelerations are different for the prisms with the same slenderness ratio but different sizes. Moreover, compared with the prism on the ground, the prism on the top floor has significantly higher rocking demand, while the prism on the second floor may have lower rocking demand. Furthermore, the cylinder has higher rocking and overturning fragility than the prism with the same height and width. The rocking and overturning fragility increases as the block becomes slenderer or smaller. The proposed critical rocking acceleration under bidirectional seismic excitation in real conditions is a half of the theoretical one under unidirectional excitation.

Transperineal pelvic floor ultrasound in male.

The pelvic floor (PF) is a highly complex structure which may be affected by various stimulating factors like decreased PF support. As ultrasound can dynamically observe the position and mobility of anatomical structures, However, there are very few studies on PF ultrasound in males. Twenty-one male patients with normal conditions underwent transperineal pelvic floor ultrasound (TPFU) examination. Ultrasound was performed in a supine lithotomy position. The probe was pressed on the sagittal plane of the perineum and adjusted till the anorectal angle, as well as bladder, were located and the median prostate and pubic symphysis were visible on the sagittal plane. TPFU was carried out to observe the patterns of pelvic floor movement during different phases, measure ultrasound parameters of the PF in men, and assess the potential applications and prospects of the male PF. Two-dimensional male PF ultrasound can detect the bladder, prostate, male urethra, anus, rectum. Resting, Valsalva, and contraction phases of the PF are clearly shown, the pelvic organs in the Valsalva phase shift to the dorsal foot side, and shift to the cephalic ventral side when the levator ani muscle (LAM) contracts. Three-dimensional male PF ultrasound can visually show the shape and structure of the levator ani muscle hiatus. It is a feasible examination tool for detecting PF disorders. However, there are still many fields to explore in the future.

A study to check the effectiveness of software and to analyse a 15 storey RC framed structure using tuned mass dampers

The modern fashion in the direction of systems of ever-growing stature, in addition to the usage of mild weight, excessive pleasant materials, and superior improvement techniques, has led to systems which are an increasing number of adaptable and delicately damped. There are presently some techniques to be had to lessen structural vibration. Tuned mass dampers are one of the vibration manipulate options (TMD). This studies is needed to decide the viability of the usage of TMD to govern vibration shape. The modern have a look at investigates the effect of TMD with best parameters (frequency share and mass share). TMD is used as a vulnerable tale on this case, that's idea to be made from RCC constructed as much as the pinnacle of the building. A multi-tale RC defines shape of 15 testimonies with and without TMDs has been developed. The effectiveness of the software program may be examined first, accompanied with the aid of using the introduction of a 3-d version and checking out with a FE package deal SAP2000 with direct aggregate technique. TMDs with mass proportions of 2%, 3%, and 4% are taken into account. The version is used to speak with systems placed in India's Zone 5. The structural and systemic parameters are investigated. Time records research has been considered, and the systems need to be subjected to floor motion in Gujarat for the operating with TMDs and TMD as soft-storey, with the outcomes deciphered.

An Intensity Measure for the Rocking Fragility Analysis of Rigid Blocks Subjected to Floor Motions

A novel intensity measure (IM), dimensionless floor displacement, is presented for evaluating the seismic fragility of freestanding rigid blocks subjected to one-sine acceleration pulses in this paper. The rocking responses of rigid blocks are simulated using an equivalent single-degree-of-freedom (SDOF) model with a bespoke discrete damper to account for energy dissipation. The performance of various IMs is compared using simulation results for four different block models under different excitation conditions. In comparison to some well-known IMs, the proposed IM, determined by excitation magnitude and frequency as well as block geometry parameters, displays a considerably stronger correlation with the peak rotation of the rocking block. The comparative results show that effective IMs should consider not only the excitation characteristics but also the block geometric parameters. Finally, the fragility curve generated by the proposed IM performs best by significantly reducing the dispersion.

Control Technology of Roof-Cutting and Pressure Relief for Roadway Excavation with Strong Mining Small Coal Pillar

In order to solve the problem of serious deformation and failure of surrounding rock and difficult maintenance of gob-side entries with strong mining-induced small coal pillars, taking the A110607 return airway of the Shanwenjiaba Coal Mine as the engineering background, the key parameters of roof-cutting and pressure relief control technology for roadway excavation with strong mining-induced small coal pillars were studied by using two-way concentrated blasting roof-cutting and pressure relief technology, combined with theoretical analysis, numerical simulation and a field industrial test. A collaborative control scheme of “roof-cutting pressure relief + anchor cable combined support” is proposed. The test results show that when the height of roof-cutting is 8 m, the angle of roof-cutting is 15°, and when the width of the coal pillar is 3 m, the effect of roof-cutting and pressure relief is the best. Through the field blasting test, it was determined that the blast hole spacing was 800 mm, 321 charge structure was used in the intact roof, and 221 or 211 charge structures were used in the broken roof and geological structure zones. During the driving and strong mining period, the roof and floor movement of the roof-cutting section of the roadway excavation was reduced by about 38% compared with the uncut section, and the deformation of the two sides of the roadway was reduced by about 44% compared with the uncut section. It shows that the collaborative control scheme of “roof-cutting pressure relief + anchor cable combined support” has a good effect on the roadway excavation driving of small coal pillars in strong mining.

Which typical floor movements of men’s artistic gymnastics result in the most extreme lumbar lordosis and ground reaction forces?

ABSTRACT Back pain is prevalent among gymnast populations and extreme flexion or extension of the lumbar spine along with high ground reaction forces (GRFs) are known to increase intervertebral stress. The aim of this study was to determine which postures and dynamic conditions among common floor movements provide the greatest risk of injury in men’s artistic gymnastics (MAG). For this purpose, lumbar spine curvatures, obtained through a full-body subject-specific kinematic model fed by motion capture data, and GRFs on feet and hands were compared between typical floor movements of MAG (pike jump, round off back handspring, front handspring, forward and backward tucked somersaults) performed by six adolescent gymnasts. The round off back handspring and the pike jump resulted respectively in the largest lumbar extension and flexion, and the forward tucked somersault take-off in the highest GRF. At ground impacts, the largest lumbar flexion was during the backward tucked somersault landing and only the back handspring hands ground contact phase led to lumbar extension. Such identification of high-risk conditions should enable better back pain management in gymnastics through more tailored training adaptations, particularly in case of pathologies or musculoskeletal specificities.

2022 Roger A. Mann Award Winner: Total Ankle Replacement vs Arthrodesis (TARVA) Randomized Controlled Trial: 2 Year Results

Category: Ankle Arthritis; Ankle; Hindfoot; Other Introduction/Purpose: End-stage ankle osteoarthritis (EOA) causes severe pain and chronic disability. Once non operative measures have been exhausted the two main surgical treatments include total ankle replacement (TAR) and ankle fusion (AF). Systematic reviews have confirmed that both procedures are effective but there has never been a robust randomised multicentre level I study comparing the two treatments. Our objective was to investigate and compare the clinical and cost effectiveness of TAR against AF in the treatment of end-stage ankle osteoarthritis in patients aged 50-85 years. Methods: TARVA is a multi-centre, parallel-group, open label randomised trial. Patients with EOA, aged 50-85, suitable for either procedure were recruited at 17 UK hospitals. Randomisation was carried out using a secure on-line service and was stratified by surgeon and the presence or absence of adjacent joint OA (based on an independently reviewed preoperative MRI scan). Participants were randomised 1:1 to either TAR or ankle arthrodesis. The primary outcome was the change in the Manchester Oxford Foot & Ankle Questionnaire (MOXFQ) walking/standing domain scores between pre-operation and 52 weeks post- operation. Secondary outcomes measures included FAAM; FAAM (ADL); and Sport subscale scores. Quality of life was measured using the EQ-5D-5L. Total range of tibia to floor motion was measured using a validated method. Health economic analysis used mean incremental cost per quality-adjusted life years (QALY) gained. Analysis was by intention to treat. The trial registration is ISRCTN60672307. Results: Of 933 eligible patients 303 were randomised. 282 underwent surgery. Mean age 68 (71% male). Aetiology was post- trauma in 55.3%, and inflammatory in 7.1%. Groups were well balanced at baseline on all parameters. 54% TARs were fixed bearing. 61% of fusions were performed arthroscopically. At 2 years the adjusted mean difference in the change in MOXFQ W/S between TAR & AF was -4.4(95% CI -11.38 to 2.68, p=0∙23). Post hoc analysis of the commonest implant type (fixed bearing TAR) did show a statistically significant improvement over AF (p=0∙04, -8.9, 95% CI -17.2 to -0.6). Secondary outcomes, EQ5D-VAS and FAAM were significant. Complications included wound healing issues (13.8% vs 5.5%); nerve injuries (4.3% vs 0.7%). 11.8% of AF patients had plain radiographic evidence of non-union but only 6.9% had symptoms. Reoperation rate was 7.2% for TAR vs 5.2% for AF; and revision rate was 0.7% for TAR vs 2.8% for AF. Conclusion: Patients improved in all outcomes in both arms. We did not show a significant difference in our primary outcome measure between TAR and AF overall(p=0.23), but did show significance when fixed bearing TAR alone was compared against AF(p=0.04). Secondary outcomes did show significance. Adjacent joint arthritis increases the size of effect noted between arms. There were more wound healing issues and nerve injuries in TAR group. The symptomatic non-union rate for AF is 6.9%. TAR is likely to be cost-effective compared to AF at the NICE cost-effectiveness threshold of £20,000 per Quality Adjusted Life Year gained over the patients' lifetime.

Seismic performance characterization of fire sprinkler piping systems through shake table testing

Fire sprinkler systems damaged during earthquakes can compromise building functionality either by loss of fire protection and/or flooding damage. To characterize the seismic behavior of fire sprinkler piping systems, shake table tests were conducted on a piping specimen with features representative of actual practices in New Zealand. The specimen was subjected to a set of motions including recorded floor acceleration response histories of an instrumented building in New Zealand. This paper describes the test setup and the piping specimen, and discusses the seismic response of the specimen to multiple floor motions for different bracing variations. Based on the test results reported in this paper, it can be concluded that bracing segments of piping other than the distribution pipe, such as the branch and arm-over pipes, can considerably affect the seismic demand on the system. Further, the test results confirm that the seismic demands on pipes can be considerably greater if the piping system is in resonance with the input excitation motion.

Shaking table testing of an innovative wireway vibration attenuation system

The seismic performance of the lighting systems is rarely reported in the literature, although previous studies indicate that they could be vulnerable during an earthquake. This study investigated the effect of various connectors on the seismic performance of an innovative wireway vibration attenuation system for raceway light fixtures using shaking table tests based on ICC-ES AC156 standard. The floor spectrum was created, and its compatible floor motion time history was employed as the input motion. Four typical prototypes were prepared with connectors suitable for mounting on a variety of structural components, including ceiling, H-beam frame, wall, and beam and column. The test results demonstrated that the specimens with the direct connectors (Wall and H-beam frame) had excellent seismic performance, 1.4–2.0 times higher than those with the pole connectors (Ceiling and Beam-column). Therefore, the direct connectors are proposed for this innovative system to decrease the danger of system failure during an earthquake.

Seismic overturning fragility analysis for freestanding building contents subjected to horizontal bidirectional floor motions

The rocking response of freestanding building contents simplified as rigid bodies was usually investigated in two dimensions with ground motions as the input, while their three-dimensional (3-D) rocking response subjected to horizontal bidirectional floor motions needs further investigation in both deterministic and probabilistic views. In this paper, the rocking response of freestanding 3-D rectangular blocks subjected to seismic excitations with two horizontal components are first investigated by shake table tests and finite element (FE) numerical simulation. An incremental dynamic analysis-based overturning fragility assessment method for the blocks within a building subjected to bidirectional ground motions is then proposed, using uncoupled nonlinear FE models of the block-building systems. The overturning fragility of six blocks within a four-story reinforced concrete frame structure is assessed. The influence of excitation directions, floor levels, block slenderness ratios (2.5, 3, 3.5 and 4), block sizes (size parameters of 91 mm, 182 mm and 364 mm) and intensity measurements (IMs) on the overturning fragility of the block is characterized. The experimental overturning fragility curves of three blocks in real conditions under bidirectional seismic excitations are finally obtained from the shake table tests. Rocking-torsional rotations are observed for the block with sliding not allowed. The block rocks around a side or a vertex while overturns around a side. Except the largest block, the block under bidirectional excitations is usually more and sometimes equally vulnerable to overturn in comparison to that under unidirectional excitations. The block on a higher floor is found to be more vulnerable to overturn than that on a lower floor considering the peak ground acceleration-based IM. These observations highlight on the significance of 3-D analysis for the rocking blocks considering floor acceleration amplification. This paper also enlarges the experimental database of seismic rocking response of rectangular blocks under bidirectional horizontal motions.

A predictive study of the level of performance of the kinetic sentence on the floor movement system for juniors in gymnastics with a statistical significance of the h0armonic abilities

A predictive study of the level of performance of the kinetic sentence on the floor movement system for juniors in gymnastics with a statistical significance of the h0armonic abilities

Incremental dynamic analysis of rigid blocks subjected to ground and floor motions and shake table protocol inputs

This paper reports the results of an extensive campaign of incremental dynamic analyses (IDA) of rigid rocking blocks under various loading histories, including real ground/floor motions and shake table testing protocol loading histories. Several block geometries are investigated considering various size and slenderness combinations representative of building contents, monumental elements, art objects, components of critical facilities, and other unanchored elements. The spectral response of the block to different loading histories is firstly assessed by highlighting the characteristics of the different seismic input sets. Dimensionless acceleration- and velocity-based parameters are considered as intensity measures, and the block rotation normalized considering the critical angle (i.e., dimensionless rocking amplitude) is assumed as an engineering demand parameter. The IDA curves are evaluated, and the dynamic response of the blocks is characterized in terms of: (a) type of loading history, (b) intensity measure, and (c) block geometry. New information and technical insights are presented regarding the assessment of seismic response of structural and nonstructural rocking systems. The dynamic response of the blocks subjected to the investigated protocols is found to be not always compatible with the capacities related to real ground/floor motions, often producing non-conservative estimations. The discrepancy identified between the block responses associated with the protocol inputs and real motions is found to be significantly affected by both block geometry and intensity measure.

The impact of programmed education on skill knowledge and learning some floor movements in the artistic gymnastics for students

The impact of programmed education on skill knowledge and learning some floor movements in the artistic gymnastics for students

Meningkatkan Minat dan Hasil Belajar Seni Tari Melalui Pendekatan PAIKEM Berbantuan Metode Demonstrasi Semester 2 Siswa Kelas VII-3 SMP Negeri 5 Penajam Kabupaten Penajam Paser Utara Provinsi Kalimantan Timur Tahun Pelajaran 2019/2020

Cultural Arts at SMP Negeri 5 Penajam, PPU Regency applies Integrated Cultural Arts lessons which have been developed based on the 2013 Curriculum by considering, Complexity, carrying capacity, student context. In addition to the above, the diversity of students' talents and interests is also one of the reasons for the implementation of integrated Cultural Arts lessons. However, with the amount of material and the limited time for face-to-face hours, several obstacles arise related to students. Students find it difficult, especially in dance subjects that are rarely studied at the previous school level, causing a lack of interest and student participation in the learning process. These obstacles need to be considered and find a way out by the teacher as a motivator, facilitator and evaluator in the learning process. The purpose of this research is to find out: 1) the teacher's efforts in the learning process to increase the interest of Class VII-3 students of SMP Negeri 5 Penajam in learning dance. 2) the teacher's efforts in improving student learning outcomes for Class VII-3 SMP Negeri 5 Penajam in dance lessons. This research will apply the Active, Creative, Effective, and Fun Learning (PAKEM) approach which is divided into two cycles. Based on the results of classroom action research, the teacher's efforts by applying the PAIKEM approach combined with the Demonstration technique can increase students' interest and learning achievement in the arts and culture subjects of the dance branch with competency standards for expressing themselves through dance works, especially in the basic competence of exploring floor movement patterns. dance in pairs/local groups. In the first cycle of 32 students who completed it reached 59.37% or 19 students and who did not complete there were 40.62% or 13 students, and the average score was 74.53. While in the second cycle of the 32 students who successfully completed there were 30 students or 92.75%, and the average value was 79.84. Based on the conclusions above, the research was stopped until the second cycle.

Floor motion's influence on wake asymmetry of a notchback bluff body

Large eddy simulations are used to explore the influence of floor motions on asymmetric flows around a notchback bluff body. The focus of this study is on the aerodynamic forces and the extent of natural wake asymmetry presented under moving and stationary ground conditions. The different ground condition has a notable influence on the aerodynamic force and the surrounding pressure distribution of the body. On the other hand, the wake asymmetry, known to be a sensitive phenomenon, is not evidently affected by the floor motion. However, quantitative analysis of the averaged and the statistic flow still suggests slight differences in the degree of wake asymmetry between the two ground conditions. Modal analysis applying proper orthogonal decomposition confirms that the asymmetric wake dynamics and the wake shedding frequency are not sensitive to the floor motion. The accuracy of the numerical simulation is established by a grid-independence study.

Integrated on‐land‐offshore stratigraphy of the Campi Flegrei caldera: New insights into the volcano‐tectonic evolution in the last 15 kyr

AbstractSilicic calderas are volcanic systems whose unrest evolution is more unpredictable than other volcano types because they often do not culminate in an eruption. Their complex structure strongly influences the post‐collapse volcano‐tectonic evolution, usually coupling volcanism and ground deformation. Among such volcanoes, the Campi Flegrei caldera (southern Italy) is one of the most studied. Significant long‐ and short‐term ground deformations characterise this restless volcano. Several studies performed on the marine‐continental succession exposed in the central sector of the Campi Flegrei caldera provided a reconstruction of ground deformation during the last 15 kyr. However, considering that over one‐third of the caldera is presently submerged beneath the Pozzuoli Gulf, a comprehensive stratigraphic on‐land‐offshore framework is still lacking. This study aims at reconstructing the offshore succession through analysis of high‐resolution single and multichannel reflection seismic profiles and correlates the resulting seismic stratigraphic framework with the stratigraphy reconstructed on‐land. Results provide new clues on the causative relations between the intra‐caldera marine and volcaniclastic sedimentation and the alternating phases of marine transgressions and regressions originated by the interplay between ground deformation and sea‐level rise. The volcano‐tectonic reconstruction, provided in this work, connects the major caldera floor movements to the large Plinian eruptions of Pomici Principali (12 ka) and Agnano Monte Spina (4.55 ka), with the onset of the first post‐caldera doming at ca. 10.5 ka. We emphasise that ground deformation is usually coupled with volcanic activity, which shows a self‐similar pattern, regardless of its scale. Thus, characterising the long‐term deformation history becomes of particular interest and relevance for hazard assessment and definition of future unrest scenarios.

The effect of McCarthy model on learning some basic skills on the floor movement device in gymnastics for female students

The purpose of this paper is to identifying the effect of the McCarthy model on some basic skills on the floor movement device in gymnastics for female students and identifying the preference for the effect between the McCarthy model and the method used in some basic skills on the floor movement device in gymnastics for female students. The researcher used the experimental method by designing the two equal groups with pre and post-tests to apply the vocabulary of the McCarthy model and identified the research community with the third stage students of the College, which numbered (56) students, and the students who failed and deferred were excluded, whose number is (8) Female students, so that the total number was (48) female students, and the sample was chosen by simple random lottery method with (24) female students, and it was divided equally into two groups, experimental and control after conducting the tribal tests, the members of the experimental group started applying the units prepared by the researcher and lasted for four weeks, with two developmental units each week after completing the vocabulary of the units, the researcher conducted the post-tests and collected the data, and it was statistically processed using the (spss) program. As for the most important conclusions, they were as follows: There is a positive development for the experimental and control research groups for the technical performance of the basic skills on the floor movement's device in gymnastics for female students. The exercises that were prepared according to the steps of the McCarthy model greatly helped in developing the members of the experimental group at the expense of the members of the control group in Basic skills on the device of floor movements in the gymnastics in question. As for the most important recommendations, they were: conducting research and studies to find out the effect of using the McCarthy model in developing the cognitive, kinetic and skill aspects in other sports, conducting various research and studies to compare the McCarthy model with other models or with the various teaching methods to see its impact on learning basic skills effectively gymnastics.

A probabilistic strong floor motion duration model for seismic performance assessment of non‐structural building elements

AbstractNon‐structural elements (NSEs) are not designed to be part of the structural load‐bearing system of a building but are subjected to the same dynamic environment as the supporting structure during an earthquake. Non‐structural damage and ensuing losses have exceeded structural damage and losses in many buildings during recent earthquakes that have occurred in urban regions around the world. Damage to NSEs is strongly influenced by the amplitude, the frequency content and the duration of floor motions. Although the effects of amplitude and frequency content of floor motions are well captured by floor response spectra, little attention has been given on the characterisation of floor motion duration and how it can impact damage to NSEs, particularly for those responding in the inelastic range. To contribute to a better understanding of these issues, this paper develops a probabilistic strong floor motion duration model through multiple stripes non‐linear time‐history analyses of a population of 100 code‐compliant reinforced concrete frame building models designed for a medium‐to‐high seismicity site in Italy. The resulting probabilistic model can be used when selecting historical or generating synthetic floor motions for the seismic response assessment of NSEs or when generating shake‐table test records for the seismic qualification of NSEs.

Effectiveness study of wire mesh vibration damper for sensitive equipment protection from seismic events

Wire Mesh Vibration Damper (WMVD) is proposed for the protection of vibration-sensitive equipment, such as Information Technology (IT) equipment, from seismic events. The mathematical model of the proposed isolator is primarily defined and then implemented to develop the Matlab Simscape MultibodyTM model of the WMVD isolated system subjected to earthquake induced floor motion. The latter is simultaneously generated for natural earthquake records and scaled to satisfy the GR-63-CORE (Zone 4) standard requirements via an artificial seismic time-history generation procedure, developed in the present work. In order to study the isolation effectiveness of the WMVD, comparative analysis with linear anti-seismic support is firstly provided. Results reveal that the WMVD isolated system can effectively attenuate seismic response more than 85%, whereas the seismic responses of the linearly isolated system increase by 160% as compared to the ground motion acceleration. Subsequently, an Incremental Dynamic Analysis (IDA) by specifying the operational vibration limit of the sensitive equipment mounted on the WMVD, is conducted to create the fragility curves. Considering the maximum acceleration response as engineering demand parameter, seismic fragility analysis eventually demonstrates the performance of the WMVD to protect the sensitive equipment from floor motion excitation.