Vibration Criteria Assessment due to Piling Works

In the recent years, the level and nature of the ground vibrations has been more concerned in worldwide. Vibration affected on surrounding building is often associated with the vibration from the ground that is mainly caused by internal and external sources. One of the external sources is construction activities. Identify the effects of vibration caused by piling works in construction sites was the purpose of this paper. It is also aiming to determine the vibration criteria due to piling works in Klang Valley construction site. In addition, the objective of this study is to compare the level of vibration with Department of Environment (DOE) guideline between both Kajang MRT and Klang Valley MRT construction sites. The data used for this study is obtained from past researchers and field testing is performed by using Polytec Laser Doppler Vibrometer and Rion VM-55. The data has been analyzed by using ModalV of MATLAB software. Based on the results, it can be concluded that the vibration amplitude for three distance includes 5m, 10m and 20m are located above the ISO level which stated that the area within the distances not suitable for placement of sensitive equipment. The highest value of root mean square velocity is occurred in the distance of 5m and the reading is 80000 µm/s. According to Department of Environment (DOE) guidelines, the vibration at distance of 1m and 3m at Kajang MRT will cause major damage to surrounding buildings while minor damage was produced by the vibration at 5m, 10m and 20m distance from bored piling point which located around the area of Klang Valley MRT.

Download Full-text

Effect of scanning speed on texture-elicited vibrations

Journal of The Royal Society Interface ◽

10.1098/rsif.2019.0892 ◽

2020 ◽

Vol 17 (167) ◽

pp. 20190892

Author(s):

Charles M. Greenspon ◽

Kristine R. McLellan ◽

Justin D. Lieber ◽

Sliman J. Bensmaia

Keyword(s):

Root Mean Square ◽

Laser Doppler Vibrometer ◽

Scanning Speed ◽

Mean Square ◽

Root Mean Square Velocity ◽

Dependent Change ◽

Fine Surface ◽

Neuronal Representation ◽

Human Participants ◽

Exploratory Movements

To sense the texture of a surface, we run our fingers across it, which leads to the elicitation of skin vibrations that depend both on the surface and on exploratory parameters, particularly scanning speed. The transduction and processing of these vibrations mediate the ability to discern fine surface features. The objective of the present study is to characterize the effect of changes in scanning speed on texture-elicited vibrations to better understand how the exploratory movements shape the neuronal representation of texture. To this end, we scanned a variety of textures across the fingertip of human participants at a variety of speeds (10–160 mm s −1 ) while measuring the resulting vibrations using a laser Doppler vibrometer. First, we found that the intensity of the vibrations—as indexed by root-mean-square velocity—increases with speed but that the skin displacement remains constant. Second, we found that the frequency composition of the vibrations shifts systematically to higher frequencies with increases in scanning speed. Finally, we show that the speed-dependent shift in frequency composition accounts for the speed-dependent change in intensity.

Download Full-text

Ultrasonic Synthetic Aperture Focusing Using the Root-Mean-Square Velocity

Journal of Nondestructive Evaluation ◽

10.1007/s10921-013-0198-4 ◽

2013 ◽

Cited By ~ 2

Author(s):

Ruey-Chyuan Shih ◽

Young-Fo Chang ◽

Chih-Hsiung Chang ◽

Po-Yen Tseng

Keyword(s):

Root Mean Square ◽

Synthetic Aperture ◽

Mean Square ◽

Root Mean Square Velocity ◽

Synthetic Aperture Focusing

Download Full-text

6. Root-Mean-Square Velocity Estimation

Covariance Analysis for Seismic Signal Processing ◽

10.1190/1.9781560802037.ch6 ◽

1999 ◽

pp. 83-108

Author(s):

R. Lynn Kirlin

Keyword(s):

Root Mean Square ◽

Velocity Estimation ◽

Mean Square ◽

Root Mean Square Velocity

Download Full-text

Seismic Imaging of Small Faults in Coal Seams by Prestack Time Migration

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.556-562.592 ◽

2014 ◽

Vol 556-562 ◽

pp. 592-596

Author(s):

Su Zhen Shi ◽

Juan Li ◽

Yi Chen Zhao ◽

Li Biao Yang ◽

Yao Tang ◽

...

Keyword(s):

Root Mean Square ◽

Seismic Data ◽

Mean Square ◽

Root Mean Square Velocity ◽

Coal Seams ◽

Time Migration ◽

Geological Conditions ◽

Small Fault ◽

Prestack Time Migration ◽

And Migration

In order to improve imaging precision of small structures and small fault blocks of coal seams, the prestack time migration method is used for imaging. Preserved amplitude processing (PAP) is applied to prestack gather firstly after geological data and original seismic data of the exploration area are fully understood. Initial root mean square velocity field is established through the method of picking up root mean square velocity on CRP gather. Then, a precise root mean square velocity model is created after continuous iteration and modification. Meanwhile, appropriate algorithm and migration parameters are selected during the migration process. Finally, the imaging of small fault blocks and small faults in the prestack time migration section is clear and migration is highly coinciding with the case disclosed by boreholes. It’s proved that prestack time migration is especially suitable for processing 3D seismic data of small faults and small fault blocks in coal seams with complicated geological conditions.

Download Full-text

SDSS-IV MaNGA: stellar population correlates with stellar root-mean-square velocity Vrms gradients or total-density-profile slopes at fixed effective velocity dispersion σe

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1481 ◽

2020 ◽

Vol 495 (4) ◽

pp. 4820-4827

Author(s):

Shengdong Lu ◽

Michele Cappellari ◽

Shude Mao ◽

Junqiang Ge ◽

Ran Li

Keyword(s):

Root Mean Square ◽

Total Mass ◽

Stellar Population ◽

Velocity Dispersion ◽

Mass Density ◽

Total Density ◽

Mean Square ◽

Root Mean Square Velocity ◽

Effective Velocity ◽

Hydrodynamical Simulations

ABSTRACT Galaxy properties are known to correlate most tightly with the galaxy effective stellar velocity dispersion σe. Here, we look for additional trends at fixed σe using 1339 galaxies (M* ≳ 6 × 109 M⊙) with different morphologies in the MaNGA (DR14) sample with integral-field spectroscopy data. We focus on the gradients (γrms ≡ σ(Re/4)/σe) of the stellar root-mean-square velocity ($V_{\rm rms} \equiv \sqrt{V^2 + \sigma ^2}$), which we show traces the total mass density gradient γtot derived from dynamical models and, more weakly, the bulge fraction. We confirm that γrms increases with σe, age, and metallicity. We additionally find that these correlations still exist at fixed σe, where galaxies with larger γrms are found to be older and more metal-rich. It means that mass density gradients contain information of the stellar population which is not fully accounted for by σe. This result puts an extra constraint on our understanding of galaxy quenching. We compare our results with galaxies in the IllustrisTNG hydrodynamical simulations and find that, at fixed σe, similar trends exist with age, the bulge fraction, and the total mass density slope but, unlike observations, no correlation with metallicity can be detected in the simulations.

Download Full-text