Fall Height Research Articles

Analysis of workers’ fall accidents due to formwork operations

In the construction industry, fall accidents are a critical form of accident. This research examines fall accidents in formwork operations that occurred between 1995 and 2015. This study examines the different dimensions of fall incidents, such as the level of severity of formwork activities, fall height and causes of falls using the 205 construction industry accidents reported in the Occupational Safety and Health Administration (OSHA) database, a regulatory agency in the USA. The findings revealed that most fall incidents occur at the height of less than 9.1 m (30 ft), mostly due to unprotected or unguarded edges or floor covering. Furthermore, erection and stripping activities were found to have severe risks to carpenters and moreso to the general workers who tend to have more chances of meeting such accidents; additionally, human error can also be observed. These results are intended to alert safety authorities of the need to examine the existing state of fall incidents and formulate strategies to minimise them in the future. Since OSHA does not provide in-depth information for each incident, it was impossible to ascertain the exact situation and formwork type in use at the event.

Injury Patterns after Falling down Stairs-High Ratio of Traumatic Brain Injury under Alcohol Influence.

Falling down a staircase is a common mechanism of injury in patients with severe trauma, but the effect of varying fall height according to the number of steps on injury patterns in these patients has been little studied. In this retrospective study, prospectively collected data from a Level 1 Trauma Center in Germany were analyzed regarding the injury patterns of patients admitted through the trauma room with suspicion of multiple injuries following a fall down a flight of stairs between January 2016 and December 2019. In total 118 patients were examined which where consecutively included in this study. More than 80% of patients suffered a traumatic brain injury, which increased as a function of the number of stairs fallen. Therefore, the likelihood of intracranial hemorrhage increased with higher numbers of fallen stairs. Fall-associated bony injuries were predominantly to the face, skull and the spine. In addition, there was a high coincidence of staircase falls and alcohol intake. Due to a frequent coincidence of staircase falls and alcohol, the (pre-)clinical neurological assessment is complicated. As the height of the fall increases, severe traumatic brain injury should be anticipated and diagnostics to exclude intracranial hemorrhage and spinal injuries should be performed promptly to ensure the best possible patient outcome.

Variations and heritability of phenotypic characters in the reblooming bearded iris (Iris germanica L.)

• Longer leaves on non-blooming stems and less flowers on a scape may be two phenotypes for the rebloomers to support twice flowering. • FM1 ( Iris germanica ‘Cornhusker’) was the most ideal maternal parent. • FM2 × M2 ( I. germanica ‘Delta Lady’ × I. germanica ‘HD’) was the ideal cross combination with the reblooming rate being 16.67%. • Length of fall and scape height gained the largest broad-sense heritability (88.03%) and narrow-sense heritability (66.63%), respectively. • There were correlations between the vegetative trait plant height and the floral characters. The reblooming bearded iris ( Iris germanica L.) could bloom in not only spring, but also autumn. The additional blooming seasons bring the phenotypic differences between the once-bloomers and the rebloomers. However, the lack of studies on the rebloomers’ phenotypic variations largely hinders the process of breeding. In this study, ten F 1 populations were produced according to the North Carolina Design II, using five maternal and two paternal parents. After the hybridization, the leaves of non-blooming stems were longer than their parents in all of the F 1 populations, the photosynthesis of which may provide more nutrition for the additional blooming. Furthermore, the fewer flowers on a scape in F 1 could be another phenotype to support twice flowering. The six floral characters (height of individual flower (HF), diameter of flower (DF), length of fall (LF), width of fall (WF), length of standard (LS) and width of standard (WS)) were all largely improved in the cross combination of FM2 × M2 ( I. germanica ‘Delta Lady’ × I. germanica ‘HD’) over both parents. FM2 × M2 was considered as the ideal cross combination after the comprehensive analysis of heterobeltiosis, special combining ability and reblooming rate (16.67%). The general combining ability values showed that FM1 ( I. germanica ‘Cornhusker’) tended to be the ideal maternal parent. LF and scape height gained the largest broad-sense and narrow-sense heritability (88.03% and 66.63%), respectively. The correlations between the vegetative trait (plant height) and the six floral characters (HF, DF, LF, WF, LS and WS) enabled the selection of the large-flower individuals at the stage of vegetative growth. All these results presented a preliminary profile of the phenotypic characters inheritance, and may guide the future breeding of the rebloomers.

Test-retest reliability of the FALL FIT system for assessing and training protective arm reactions in response to a forward fall

The use of the hands and arms is an important protective mechanism in avoiding fall-related injury. The aim of this study was to evaluate the test-retest reliability of fall dynamics and evokd protective arm response kinematics and kinetics in forward falls simulated using the FALL simulator For Injury prevention Training and assessment system (FALL FIT). Fall FIT allows experimental control of the fall height and acceleration of the body during a forward fall. Two falls were simulated starting from 4 initial lean angles in Experiment 1 and with 4 different fall accelerations in Experiment 2. Fourteen younger adults (25.1±3.5 years) and 13 older adults (71.3±3.7 years) participated in Experiment 1 and 13 younger adults (31.8±5.7 years) participated in Experiment 2. Intraclass correlation coefficients (ICC) were used to the evaluate absolute agreement of single measures at each condition and averages across conditions. Average measures of fall dynamics and evoked kinematics and kinetics exhibited excellent reliability (ICC(A,4)>0.86). The reliability of single measures (ICC(A,1) > 0.59) was good to excellent, although 18% of single measures had a reliability (ICC(A,1)) between 0.00 and 0.57. The FALL FIT was shown to have good to excellent reliability for most measures. FALL FIT can produce a wide range of fall dynamics through modulation of initial lean angle and body acceleration. Additionally, the range of fall velocities and evoked kinematics and kinetics are consistent with previous fall research.•The FALL FIT can be used to gain further insight into the control of protective arm reactions and may provide a therapeutic tool to assess and train protective arm reactions.

The detachment mechanism of the rockslide causing the Chamoli February 7th, 2021 debris flow disaster

Abstract On February 7th, 2021, a rockslide of about 20 Mio m³ detached in a height of 5600 m asl. from the northern flank of Mount Ronti (Chamoli district, Uttarakhand state, India), turned into a rock mass fall and produced a debris flow. When the rock mass hit the Ronti Gad valley after a fall height of 1800 m the rock mass mixed with melting dead ice together with snow and ice avalanche material of previous debris flows. The debris flow destroyed hydroelectric infrastructure between 10 - 20 km down the valley killing 204 people either working at or visiting the power plants. By combining remote sensing, structural geology and kinematics/mechanical analysis of the rockslide, we demonstrate that a 600 m wide and almost 800 m long block of quartzite, bordered laterally by two joints and a newly formed tension crack on the top detached from an underlying layer of biotite-rich paragneisses. Assuming full hydrostatic heads in both joints and in the tension crack as well as 75% of the full hydrostatic head in the lower boundary surface between quartzites and paragneisses, the rock block analysis yields a friction angle of 32° for both joints, which is a plausible value of the friction angle of joints in quartzites. The detachment of the block has been the result of the widening of the tension crack on top, of a progressive propagation of the lateral joints together with a catastrophic failure of the detachment plane at the border between quartzites and paragneisses. At the time of the failure, all discontinuities must have been almost completely filled with water raising the question, if the frequency of rockslides in the Himalayas is increasing as temperatures rise and permafrost is thawing due to climate change.

Variability in yield parameters of onion genotypes in Bundelkhand region of Uttar Pradesh

Of the seventeen onion varieties evaluated for assessment of variability in mean performance, variances, heritability and genetic advance, (L-883 and Bhima Shweta) were most promising genotypes in respect of gross and marketable bulb yield, minimum number of bolters, rotten and multi-centred bulbs, bulb weight, equatorial bulb diameter, total soluble solids, number of leaves per plant and earliness in maturity. High values of genetic and phenotypic for gross and marketable bulb yield, average bulb weight, days to 70% neck fall and plant height indicated more opportunity of selection for these traits. High genetic advance as percentage of mean coupled with high heritability was observed for gross and marketable bulb yield and average bulb weight. Therefore, significant improvement could be expected through selection for these traits.

Design characteristics of showering aeration system

AbstractThe showering aeration system (SAS) was designed and its performance was evaluated by conducting the aeration experiments in a tank of dimension 2 × 4 × 1.5 m. Initially, the aeration experiments were conducted to optimize the radius of curvature of the SAS with different values, such as = 0, 5, 10, 15, and 20 mm, and maintain other geometric parameters, i.e. number of holes in the shower (); height of water fall (H); diameter of the shower hole (d); volume of water under aeration (V) and water flow rate (Q) as constants. The optimum radius of curvature () was found to be 10 mm. The aeration experiments were further conducted with four different non-dimensional geometric parameters such as the number of holes , the ratio of the height of water fall to the length of shower arm the ratio of the diameter of the hole to the length of shower arm and the ratio of the volume of water to the cube of the length of shower arm The Response Surface Methodology and Box–Behnken Design were used to optimize the non-dimensional geometric parameters of the SAS to maximize the Non-Dimensional Standard Aeration Efficiency. The result indicates that the maximum NDSAE of 16.98 × 106 was obtained from the SAS performance at = 80; = 2; = 4 and = 48.

Angle of repose of snow: An experimental study on cohesive properties

The angle of repose is a measure reflecting the internal friction and cohesion properties of a granular material. In this paper, we present an experimental setup and measurements for the angle of repose of snow for seven different snow samples over a large range of temperatures. The results show that the angle of repose is dependent on the fall height, the temperature, and the grain size of the snow. These variables are quantified, and their interdependencies are separately studied. With increased snow temperature, the angle of repose increases, and this can be explained by the presence of a liquid layer on ice that can be thermodynamically stable at temperatures below the melting point of water. With decreasing grain size the angle of repose also increases which is expected since the cohesive energy decreases more slowly than the grain mass. For increasing fall height, the snow grains generally accelerate to larger collisional velocities, yielding a smaller angle of repose. In general, the dimensionless cohesion number was found to largely reflect the dependencies of the variables and is therefore useful for understanding what affects the angle of repose. The results demonstrate that the drag force and collision dynamics of ice grains are important for understanding how snow accumulates on a surface, for example if one desires predicting snow accretion by simulating a dispersed cloud of snow.

Prehospital Factors Associated with Refractory Traumatic Arrest.

Objective Identification of the prehospital factors associated with a poor prognosis of immediate traumatic arrest should help reduce unwarranted treatment. We aim to reveal the clinical factors related to death after traumatic arrest on the scene. Methods We performed a multicenter (4 tertiary hospitals in urban areas of South Korea) retrospective study on consecutive adult patients with trauma arrest on scene who were transferred by fire ambulance from January 2016 to December 2018. Patients with death on arrival in the emergency room (ER) were excluded. Prehospital data were collected from first aid records, and information on each patient's survival outcome in the ER was collected from an electronic database. Patients were divided into ER death and ER survival groups, and variables associated with prehospital trauma were compared. Results A total of 145 (84.3%) and 27 (15.7%) patients were enrolled in the ER death and survival groups, respectively. Logistic regression analysis revealed that asystole (OR 4.033, 95% CI 1.342–12.115, p = 0.013) was related to ER death and that ROSC in the prehospital phase (OR 0.100, 95% CI 0.012–0.839, p = 0.034) was inversely related to ER death. In subgroup analysis of those who suffered fall injuries, greater height of fall was associated with ER death (15.0 (5.5–25.0) vs. 4.0 (2.0–7.5) meters, p = 0.001); the optimal height cutoff for prediction of ER death was 10 meters, with 66.1% sensitivity and 100% specificity. Conclusions In cases of traumatic arrest, asystole, no prehospital ROSC, and falls from a greater height were associated with trauma death in the ER. Termination of resuscitation in traumatic arrest cases should be done on the basis of comprehensive clinical factors.

Tree Stand-Related Injuries in Nonadmitted and Admitted Patients at a Level 2 Trauma Center in Michigan: 2015-2019.

Tree stand-related injuries (TSRI) are more common than firearm-related injuries in hunters. Most previous studies on the topic used trauma databases that only include admitted patients. This study characterizes injury patterns found in nonadmitted and admitted TSRI patients presenting to a level 2 Michigan trauma center. TSRI prevention interventions are also discussed. Cases were obtained through a retrospective chart review of the Henry Ford Allegiance Health trauma registry and EPSi cost-accounting database from 2015 to 2019. Keywords searched included fall, hunter, tree, tree stand, treestand, ICD 9 diagnosis (E884.9_Other accidental fall from one level to another), and ICD 10 diagnosis (W14.XXXA_Fall from tree, initial encounter). We analyzed age, sex, body mass index, injury severity score, disposition, alcohol use, injuries sustained, reported height of fall, and narrative of fall. Thirty-three patients were identified. Patient age was 45±13 y (mean±SD). All patients were male. Injury severity score for nonadmitted patients was 2±1 vs 13±11 in admitted patients. Thirty-three percent of cases were nonadmitted; 67% were admitted. The most common injuries sustained were spinal (33%) and lower extremity fractures (15%). The average yearly TSRI case rate was 5.73 per 10,000 hunters in the study area. Our study found that spinal and lower extremity fractures were the most common injuries sustained. One-third of our patients were nonadmitted and therefore not included in the Henry Ford Allegiance Health trauma registry. Some nonadmitted patients had significant injuries requiring specialist consultation, orthopedic braces, or outpatient surgery.

Falls From Height, Facial Injuries and Fatalities: An Institutional Review.

Retrospective cohort review. To investigate the relationship between falls from height and facial injuries. This is a retrospective cohort study, conducted over a 7-year period, of the medical records of all patients who presented to hospital for a maxillofacial injury following a fall from height. Fall heights were classified as low falls (1-3m), high falls (3-10m) and very high falls (≥10m). A total of 111 patients with 218 facial bone fractures were identified (78 men, 33 women and mean age 50.3years). High falls were the most common (n = 58, 52.3%). Multiple fractures were identified in 51 (46.0%) patients. Orbital and middle third fractures were the most prevalent. Nasal, mandible, bilateral and fractures involving more than one facial third, increased as fall height increased, as did the requirement for operative fixation. The majority of patients had an associated injury (n = 100, 90.1%) and overall mortality was 6.3%. Falls from height are prevalent and there is a trend towards increased severity of facial injury, surgical intervention and associated morbidity as fall height increases. Falls from height are a significant public health concern and an important facet of maxillofacial trauma to recognise, as is the requirement for an interdisciplinary approach as they present to hospital.

Causal factors and risk assessment of fall accidents in the U.S. construction industry: A comprehensive data analysis (2000–2020)

This study delves into investigating the leading factors of occurring 23,057 fall accidents in the United States construction industry over 20 years (1/2000–8/2020) recorded in the Occupational Safety and Health Administration (OSHA) database. Additionally, the contributions are elicited in terms of diverse dimensions of fall accident, such as project type, construction end-use, work activity, worker's occupation and age, fall location and height, accident time, injury degree, and fall protection. The data is analysed using frequency analysis to obtain the trends of fall accidents, correlation analysis between the accident factors and the injury degree, and logistic regression analysis to establish a prediction model that can diagnose fatal and nonfatal accidents. The results emphasized that the proportion of fall accidents increased substantially, and there was egregious evidence that the usage of fall protection has no considerable improvement. Besides, most of the fall accidents were (1) from heights<9.15 m, (2) among the roofers, (3) occurring on new commercial buildings and residential projects with low cost, (4) during the time intervals 10:00–12:00 and 13:00–15:00, (5) among older workers which alert that the experience might not be enough to diminish the accident. The correlation analysis revealed the fall factors that were significantly associated with the injury degree. Subsequently, a logistic regression model was done to predict the injury outcome (fatal/nonfatal). It was found that the prediction model could correctly diagnose the injury degree outcome by 77.7% depending on the selected predictors of the fall accident. Furthermore, the odds of reporting fatal or nonfatal accidents from the prominent factors of fall were calculated, enhancing the risk assessment to avoid the implications of falls. This study might encourage the safety managers to apply proactive and preparedness procedures for reducing fall accidents and prioritize risks according to the likelihood of fall risk and injury characteristics by applying appropriate safety regulations.

Potential of impact-based weight sensing of individual Chinese cabbage for real-time yield monitoring

Yield monitoring is one of the basic components of precision agriculture. It provides information on the spatial variability of yield in the field. The objective of this study was to estimate the weight of Chinese cabbage through impact force measurements using a weighing sensor. The sensor was installed to receive the impact of Cabbage as it dropped off an inclined conveyor. The investigated experimental variables were fall height, plate angle to the horizontal, and conveyor speed. The load cell was calibrated, with an R2 value of 0.96. The mean absolute percentage error (MAPE), root-mean-square error (RMSE), and correlation coefficient (R2) were the statistical indicators used to describe the accuracy of the estimates. The fall height had little effect on the precision of the yield sensor. The least sensing precision was 18.75%, observed at an angle of 30° with a conveyor speed of 0.05ms-1. The MAPE for cabbage weights were<3% at 40° and 0.2 ms−1 for both fall heights. The experiments showed the potential of measuring individual cabbage weights for yield estimation.

Paediatric elbow fractures and public play spaces: adherence to standards for children’s playground equipment and surfacing

BackgroundSupracondylar humerus fractures (SCHF) are the most common fractures sustained following a fall onto an outstretched hand among healthy children, and one of the leading causes of hospital admission and...

Pemanfaatan Arus Air untuk Pembangkit Listrik Tenaga Micro Hidro

One of the problems being faced in several regions in Indonesia is the source of electrical energy. The demand for electricity from year to year has increased. The development of free energy technology needs to be developed to cover the rapidly increasing demand for electricity. One that can be developed is micro-hydro power plant technology that utilizes water flow as a source of electricity. To make a micro hydro power plant, it is necessary to do research on the available discharge and how much energy and power is generated at that location. The purpose of this community service activity is to help the community find out the potential of river flows in Toba Village, South Siantar District, Pematangsiantar City in its utilization for micro hydro power plants. The method of implementing the activity is Head observation (falling height), river flow velocity, river width, and river flow depth. From the results of observations and measurements of discharge at the service location, it is known that the head (fall height) is 0.5 meters, the river flow speed is 0.74 m/s, the river width is 6.5 meters and the river flow depth is 0.3 meters so that an empirical calculation of the generator discharge is obtained at 1.433 m 3 /sec., and the power that can be generated is 7.08 kW.

Landslides triggered by the 2018 Mw 7.5 Palu supershear earthquake in Indonesia

On September 28th, 2018, a supershear earthquake of moment magnitude (Mw) 7.5 struck the Palu area in central Sulawesi, Indonesia. To gain insight into landslides triggered by the Palu earthquake, a detailed landslide interpretation project was carried out in the meizoseismal area. To establish a co-seismic landslide inventory, we collected high-resolution images, including Worldview pre- and post- earthquake images, Sentinel pre- and post- earthquake images and Google Earth pre- and post- earthquake images. The results show that the Palu event triggered at least 7063 co-seismic landslides, including 8 flowslides. The total landslide area is 29.7 km2, with the highest density being 96 landslides/km2. The rock type (Kambuno granite) is a dominant factor influencing the landslide distribution; the average landslide H/L (H is the fall height and L is the horizontal length of an entire landslide) is 0.56. The flowslides that occurred in the Palu Basin are seismic liquefaction-induced landslides that failed along very gentle slopes (generally, slopes that are <3°) and traveled hundreds to thousands of meters, and the average H/L was 0.021.

Field measurement and numerical simulation of the relationship between the vertical wind environment and building morphology in residential areas in Xi'an, China.

The inadequate consideration of the impact of building morphology on ventilation efficiency in many urban residential areas has resulted in a series of environmental problems that threaten human health. The purpose of this paper is to establish a predictive model between ventilation efficiency and building forms in residential areas. First, the characteristics of the vertical wind profile in residential areas were measured using unmanned aerial vehicle (UAV). Second, the wind speed ratio (WSR) at different height levels under the impact of morphological index (floor area ratio, building density, average building height, enclosure degree, height fall, and maximum building height) in the residential area was simulated by ENVI-met. Two kinds of prediction formulas were finally obtained: (1) the average ventilation efficiency at the pedestrian level and (2) the prediction formula of WSR at different heights. The results show that the wind speed (WS) in residential area below 35 m is about 0.6 m/s lower than that in green park. The numerical simulation shows that the mean WSR at the pedestrian level is negatively correlated with each index, and the height fall morphological index has the largest impact on the WSR at different heights. The research provides a reference for the optimal planning and design of ventilation efficiency of residential buildings, especially those in static wind areas.

Effects of local topography on the mobility of rock avalanches: A statistical analysis based on 36 cases from south-western China

Rock avalanches are the extremely rapid flow-like movements of dry debris with extreme destructive potential. The mobility of these landslides can be characterised with Fahrböschung (defined as the ratio of fall height H over runout distance L) and runout distance. Here we statistically analyze the effects of local topography on the mobility of rock avalanches using a database that includes 36 well-documented events that occurred in south-western China, half of which induced by the 2008 Wenchuan earthquake. The analysis is conducted by distinguishing the three basic confinement categories of the rock avalanches, i.e. L-confined (laterally confined), U-confined (unconfined) and F-confined (frontally confined). The results of simple linear regression for H/L ratio and of multiple linear regression for runout distance L indicate that runout distance is preferable as a measure of mobility compared with H/L ratio due to the higher coefficient of determination. Moreover, the box-plots of residuals of the logarithm of runout distance indicated that frontal confinement tends to reduce runout distance, while lateral confinement enhances it. However, additional statistical analyses should be conducted exploiting a larger database of rock avalanches from a wider variety of environments.

EFFECTS OF WRIST GUARD AND ELBOW ARREST STRATEGY ON IMPACT FORCE IN FORWARD FALLS

Wrist guards are widely used for preventing distal radius fracture during in-line skating and snowboard-related activities. However, more than half of people wearing wrist guards nonetheless sustain a fracture of the wrist in forward falls. Accordingly, this study evaluates the effects of three factors, namely the wrist guard design, the fall height and the arrest strategy, on the impact force during a forward fall onto a single outstretched hand. Fifteen physically healthy male participants volunteered for the biomechanical investigation. None of the participants had a previous history of upper extremity injuries or disorders. A 1000[Formula: see text]Hz AMTI force plate was used to measure the ground reaction force (GRF) in forward falls performed using a self-built release system onto a single hand. The GRF and impact time were analyzed in terms of three factors, namely (1) the wrist guard design, including bare hand (BH), conventional wrist guard (WG), wrist guard pad on palm (WG+), and WG+ with no lower splint (WG[Formula: see text]; (2) the elbow arrest strategy, including elbow extended and elbow flexed; and (3) the fall height, including 4[Formula: see text]cm and 8[Formula: see text]cm. The impact force and loading rate significantly increased with an increasing fall height. However, the elbow flexed strategy attenuated the GRF peak force and delayed the point of peak impact force. The GRF in the WG, WG+ and WG− conditions was significantly lower than that in the BH condition. Overall, a lower fall height, a wrist guard with a compliant pad (WG+ or WG[Formula: see text], and an elbow flexed strategy reduced the impact force, delayed the peak impact force, and reduced the loading rate in forward falls.

Multi-layer casting of self-consolidating concrete: Influence of mortar rheology and casting parameters on the inter-layer bond strength

Inter-layer bond strength is a critical factor to achieve structurally sound monolithic concrete structures. This paper discusses the effects of the cementitious paste volume (CP%vol), structural build-up of mortar (Athixm), and their interactions with casting parameters (i.e., free fall height (HFF), and delay time) on the residual bond strength of multi-layer self-consolidating concrete. It is found that the residual bond strength can be improved by increasing the CP%vol and HFF, or by reducing the delay time and Athixm. Out of the factors investigated, Athixm has the largest effect on both the residual bond strength and the critical delay time.