Slanted Ground Research Articles

A Parametric Study on Composite G+8 Structure With Application of Damper on Different Locations Using Time History Analysis

Abstract: The world's population has been growing quite quickly in recent years. Major cities, in particular, have relatively dense populations, which has increased demand for new homes. Because there isn't enough land for new construction in the majority of the old cities, high-rise buildings are moving into mountainous areas. These days, there is more competition to build high rise buildings all over the world as a result of certain developed nations building extremely tall skyscrapers to demonstrate their power and technology to the rest of the world. Buildings on sloping terrain, however, have different structural configurations than those on level terrain, which causes them to vibrate more during earthquake-induced ground motions, resulting in higher displacements and shears. Increased floor displacement results in damage to the structural components, rendering the structure unusable or, in the worst situation, collapsing as a whole. Reducing the amount of seismic energy that enters slanted ground buildings is essential to preventing damage. This can be done by absorbing the majority of the vibrations that an earthquake produces. There are numerous ways to lessen a structure's seismic reaction, including base isolation, shear walls, bracings, dampers, and more. Because of their effectiveness and simplicity of usage, damping devices are particularly well-liked among these methods. The eight-storey building model with four distinct cases—bare frame, bare frame with damper on corners, bare frame with damper on Central Bay, and bare frame with damper on Alternate Bay—is taken into consideration in this research examination. For modeling, use ETABS 2016 Ultimate programme. Utilize time history analysis as well to investigate how earthquake loading affects structures

Seismic analysis of Multi storey Building on Sloping Ground and Flat Ground by using ETABS

Due to urbanization and industrialization, which paved the door for the development of tall, multi-story structures on mountainous terrain, land is scarce in emerging nations like India. Buildings built on hilly terrain differ from those built on flat terrain due of their uneven and asymmetrical vertical and horizontal structures. These buildings are also significantly more vulnerable to earthquake pressures when located in mountainous terrain. The primary goal of the current endeavor is to investigate how structures behave on level and sloping terrain. Hilly places require different construction configurations than level areas. Hill structures vary from those on lowlands in that they are torsionally linked, highly irregular, and asymmetrical in both the horizontal and vertical planes. As a result, they are vulnerable to severe damage when an earthquake strikes. The behavior of a multi-story structure with two distinct slope angles was attempted to be studied in this paper, and a comparison with flat ground was made. by taking Earthquake Zone II into account. Buildings on level ground and buildings on slanted ground are compared. The models are created with the aid of the structural analysis program ETABS. Response spectrum analysis is used for analysis. The analysis’s findings, including storey shear, storey drifts, moments, and displacement, are tabulated and examined.

The changes of lumbar muscle flexion-relaxation phenomenon due to antero-posteriorly slanted ground surfaces

Uneven ground surface is a common occupational injury risk factor in industries such as agriculture, fishing, transportation and construction. Studies have shown that antero-posteriorly slanted ground surfaces could reduce spinal stability and increase the risk of falling. In this study, the influence of antero-posteriorly slanted ground surfaces on lumbar flexion-relaxation responses was investigated. Fourteen healthy participants performed sagittally symmetric and asymmetric trunk bending motions on one flat and two antero-posteriorly slanted surfaces (−15° (uphill facing) and 15° (downhill facing)), while lumbar muscle electromyography and trunk kinematics were recorded. Results showed that standing on a downhill facing slanted surface delays the onset of lumbar muscle flexion-relaxation phenomenon (FRP), while standing on an uphill facing ground causes lumbar muscle FRP to occur earlier. In addition, compared to symmetric bending, when performing asymmetric bending, FRP occurred earlier on the contralateral side of lumbar muscles and significantly smaller maximum lumbar flexion and trunk inclination angles were observed.Practitioner Summary: Uneven ground surface is a common risk factor among a number of industries. In this study, we investigated the influence of antero-posteriorly slanted ground surface on trunk biomechanics during trunk bending. Results showed the slanted surface alters the lumbar tissue load-sharing mechanism in both sagittally symmetric and asymmetric bending.

The Effects of Uneven Ground Surface on Trunk Biomechanical Responses during Sudden Loading

As a significant contributory factor to low back injury, sudden loading during manual material handling often occurs on uneven ground surfaces. The present study investigated the effects of laterally slanted grounds on trunk biomechanical responses during sudden external loading. 13 male subjects experienced sudden loading of 6.8 kg while standing on a laterally slanted ground of 0 degree, 15 degree and 30 degree. The results showed that peak L5/S1 joint compression forces in the 30 degree condition was 10.5% and 6.5% greater than the 0 degree and 15 degree conditions, respectively. In addition, 30 degree condition also generated 14.8% and 15.1% larger increase in trunk flexion angle compared with the 0 degree and 15 degree conditions, respectively. These findings suggest that standing on a laterally slanted ground could increase the risk of low back injury, and should therefore be avoided in a work place.

Effects of Uneven Ground Surface on Human Balance

The effect of anteroposteriorly slanted ground surface on human posture control at fully flexed trunk postures was investigated in this study. Custom made wooden apparatus were used to simulate slanted ground surfaces, the slanted were set at -15, 0 and 15 degrees respectively. The flat ground condition was included in the study as a control. Fourteen healthy male subjects were asked to maintain in fully flexed trunk posture while standing on different ground surfaces. The segmental sway motion of C7, T12 and S1 spinal vertebrae in the anteroposterior (AP) and mediolateral (ML) directions were recorded. Results showed that when standing on an anteroposteriorly slanted ground surface and facing downhill (i.e. -15 degree condition) subjects consistently demonstrated the highest sway speeds and reported the highest subjective rating of instability. Therefore, we concluded that, when standing on an anteroposteriorly slanted ground surface in a fully flexed trunk posture facing downhill may result in much higher risk of falling in comparison to facing the opposite direction.

The assessment of material-handling strategies in dealing with sudden loading: the effect of uneven ground surface on trunk biomechanical responses

As a major risk factor of low back injury, sudden loading often occurs when performing manual material-handling tasks on uneven ground surfaces. Therefore, the purpose of the current study was to investigate the effects of a laterally slanted ground on trunk biomechanical responses during sudden loading events. Thirteen male subjects were subjected to suddenly released loads of 3.4 and 6.8 kg, while standing on a laterally slanted ground of 0°, 15° and 30°. The results showed that 8.3% and 5.6% larger peak L5/S1 joint compression forces were generated in the 30° condition compared with the 0° and 15° conditions, respectively. The increase of L5/S1 joint moment in the 30° condition was 8.5% and 5.0% greater than the 0° and 15° conditions, respectively. Findings of this study suggest that standing on a laterally slanted ground could increase mechanical loading on the spine when experiencing sudden loading.Practitioner Summary: Sudden loading is closely related to occupational low back injuries. The results of this study showed that the increase of slanted ground angle and magnitude of load significantly increase the mechanical loading on the spine during sudden loading. Therefore, both of these two components should be controlled in task design.

The changes of lumbar muscle flexion–relaxation response due to laterally slanted ground surfaces

Lifting tasks performed on uneven ground surfaces are common in outdoor industries. Previous studies have demonstrated that lifting tasks performed on laterally slanted ground surfaces influence lumbar muscle activation and trunk kinematics. In this study, the effect of laterally slanted ground surfaces on the lumbar muscle flexion–relaxation responses was investigated. Fourteen participants performed sagittal plane, trunk flexion–extension tasks on three laterally slanted ground surfaces (0° (flat ground), 15° and 30°), while lumbar muscle activities and trunk kinematics were recorded. Results showed that flexion–relaxation occurred up to 6.2° earlier among ipsilateral lumbar muscles with an increase in laterally slanted ground angle; however, the contralateral side was not affected as much. Our findings suggest that uneven ground alters the lumbar tissue load-sharing mechanism and creates unbalanced lumbar muscle activity, which may increase the risk of low back pain with repeated exposure to lifting on variable surfaces. Practitioner Summary: Uneven ground surfaces are ubiquitous in agriculture, construction, fishing and other outdoor industries. A better understanding of the effects of laterally slanted ground surfaces on the interaction between passive and active lumbar tissues during lifting tasks could provide valuable knowledge in the design of preventive strategies for low back injuries.

Lifting Performed on Laterally Slanted Ground Surfaces

Many outdoor work environments (e.g. agriculture and construction) require manual material handling activities on variable grade ground surfaces. Quantifying biomechanical responses for lifting under these conditions may provide insight into the etiology of lifting-related injuries. The aim of the current study was to quantify the effect of laterally slanted ground surfaces on biomechanical responses. Ten subjects performed lifting exertions (using a 40% of max load) while standing on a platform that was laterally tilted at 0, 10, 20 and 30 degrees from horizontal. During the lifting tasks the whole body kinematics were collected, which were later used in a dynamic biomechanical model to calculate the time-dependent moment about L5/S1 and the time-dependent lateral forces acting on the body segments. The results showed a consistent reduction in the peak dynamic L5/S1 moment (decreased by 9%) and an increase in the lateral forces (increased by 111%) with increasing slant angle.

A study of lifting tasks performed on laterally slanted ground surfaces

Lifting in most industrial environments is performed on a smooth, level ground surface. There are, however, many outdoor work environments (e.g. agriculture and construction) that require manual material handling activities on variable grade ground surfaces. Quantifying the biomechanical response while lifting under these conditions may provide insight into the aetiology of lifting-related injury. The aim of the current study was to quantify the effect of laterally slanted ground surfaces on the biomechanical response. Ten subjects performed both isometric weight-holding tasks and dynamic lifting exertions (both using a 40% of max load) while standing on a platform that was laterally tilted at 0, 10, 20 and 30° from horizontal. As the subject performed the isometric exertions, the electromyographic (EMG) activity of trunk extensors and knee extensors were collected and during the dynamic lifting tasks the whole body kinematics were collected. The whole body kinematics data were used in a dynamic biomechanical model to calculate the time-dependent moment about L5/S1 and the time-dependent lateral forces acting on the body segments. The results of the isometric weight-holding task show a significant (p < 0.05) effect of slant angle on the normalized integrated EMG values in both the left (increase by 26%) and right (increase by 70%) trunk extensors, indicating a significant increase in the protective co-contraction response. The results of the dynamic lifting tasks revealed a consistent reduction in the peak dynamic L5/S1 moment (decreased by 9%) and an increase in the instability producing lateral forces (increased by 111%) with increasing slant angle. These results provide quantitative insight into the response of the human lifter under these adverse lifting conditions.

110 竹の適応構造の研究(O.S.1-3 適応構造/安全構造)(オーガナイズドセッション1 知的材料・構造システム)

Bamboo grown on the slanted ground cannot grow straight up. Because it is subjected to a large bending moment due to its own weight. To avoid it the bamboo must be bent toward the gravitational direction. This bent part must be reinforced in some way to support the upper portion of the bamboo, for example reinforced by the reaction wood for the most of trees. This paper presents how bamboo reacts such over loaded circumstances. Typically, the cross-section of the bamboo culm changes from circle to ellipse which is different from trees. It is concluded that the shapes of the reaction wood are closely related to the loaded bending moment.