Comparison of Seismic Behaviour for a Single Unit Tunnel Form RC Building before and after Repaired

2014 ◽  
Vol 905 ◽  
pp. 254-258 ◽  
Author(s):  
S.A. Anuar ◽  
Nor Hayati Hamid ◽  
M.H. Hashim
Keyword(s):  
Near Field ◽  
Combination Method ◽  
Seismic Behaviour ◽  
Equivalent Viscous Damping ◽  
Code Of Practice ◽  
Carbon Fiber Reinforce Polymer ◽  
Strength Capacity ◽  
Before And After ◽  
Lateral Strength ◽  
Angle Steel

Repairing and strengthening the structures are gaining more attention from many researchers and structural engineers after the structures suffered damages from natural disasters. Tunnel form RC buildings which are not designed according to seismic code of practice are very vulnerable to ground motion when located to near field earthquake. This paper presents the method of repair and strengthening of 3-storey tunnel form building subjected to in-plane lateral cyclic loading. The building was strengthened using the combination method of steel angle, steel plate and Carbon Fiber Reinforce Polymer (CFRP) sheet. The results show that the lateral strength capacity is increase by 15.66%, ductility increase by 53.57% and equivalent viscous damping increase by 28.88% for the first cycle and 33.65% for the second cycle. However, the stiffness of the structure reduce by 56.6%. It can be concluded that this method can be adopted for the damage of tunnel form building system.

Retrofitting of a Double Unit Tunnel Form Building Using Additional RC Wall, Steel Angle and CFRP

2014 ◽  
Vol 661 ◽  
pp. 123-127 ◽  
Author(s):  
Nor Hayati Hamid ◽  
S.H. Anuar ◽  
N.L. Azmi
Keyword(s):  
Cyclic Loading ◽  
Low Cost ◽  
Seismic Retrofitting ◽  
Fiber Reinforced Polymer ◽  
Viscous Damping ◽  
Equivalent Viscous Damping ◽  
Reinforced Polymer ◽  
Steel Angle ◽  
Before And After ◽  
Lateral Strength

Tunnel form construction is widely known as modern construction method that enables the construction of horizontal and vertical elements simultaneously. It is quickly construct low cost, high quality and earthquake safe to construct cellular buildings. Main objective of this study is to determine the seismic retrofitting performance of a double unit tunnel form building when retrofitted using additional RC wall, steel angle and Carbon Fiber Reinforced Polymer (CFRP) when tested under in-plane lateral cyclic loading. A comparison of tunnel form building was made before and after retrofitting in terms of lateral strength, stiffness, ductility and equivalent viscous damping. Result indicates that retrofitting method using additional RC wall, steel angle and CFRP was able to increase the lateral strength, ductility and equivalent viscous damping under in-plane lateral cyclic loading. The result also shows the effectiveness of additional RC wall, steel angle and CFRP in improving the shear resistances and deformation capacities of concrete structures and delaying their stiffness degradation under earthquake loading.

Comparison of Seismic Performance between Single and Double Unit Tunnel Form Building under In-Plane Lateral Cyclic Loading

2014 ◽  
Vol 567 ◽  
pp. 687-692 ◽  
Author(s):  
Shamilah Anudai Anuar ◽  
Nor Hayati Abdul Hamid
Keyword(s):  
Cyclic Loading ◽  
Seismic Performance ◽  
Experimental Work ◽  
Single Unit ◽  
Viscous Damping ◽  
Equivalent Viscous Damping ◽  
Significant Percentage ◽  
Percentage Difference ◽  
Strength Capacity ◽  
Lateral Strength

This paper summarizes the comparison of seismic performance between single and double unit tunnel form building (TFB) under in-plane lateral cyclic loading. Experimental work was carried out to determine the lateral strength capacity, stiffness, ductility, and equivalent viscous damping (EVD) for both specimens. The comparisons of these parameters for both specimens were made to determine its percentage difference. The maximum lateral strength capacity obtained from single unit TFB with 8.68% higher than double unit TFB. As for stiffness behaviour, single unit was found to be much more stiffened compared to double unit. The EVD value showed that single unit absorbed much more energy compared to double unit of TFB. However, double unit TFB indicated a significant percentage of increment compared to the single unit TFB. Therefore, double unit TFB is safer to be built compared to single unit especially for seismic regions.

Retrofitting of Single Unit Tunnel Form Building Using Steel Plate under Out-of-Plane Lateral Cyclic Loading

2014 ◽  
Vol 661 ◽  
pp. 95-99 ◽  
Author(s):  
Shamilah Anudai Anuar ◽  
Nor Hayati Hamid ◽  
M.H. Hashim
Keyword(s):  
Cyclic Loading ◽  
Single Unit ◽  
Steel Plate ◽  
Hysteresis Loops ◽  
Seismic Loading ◽  
Visual Observation ◽  
Equivalent Viscous Damping ◽  
Before And After ◽  
Out Of Plane ◽  
Lateral Strength

A one-third scale single unit of 3-storey tunnel form building with foundation beam was designed, constructed and tested under out-of-plane lateral cyclic loading. This building was designed according to BS8110 with no provision for seismic loading. Tunnel form building was initially tested at ±0.01% , ±0.1%, ±0.25%, ±0.5%, ±0.75%, ±1.00%, ±1.25% and ±1.5% drifts until the structure lost its lateral strength (strength degradation). Then, the specimen was repaired and retrofitted using steel plate and angle which was positioned at the wall-slab joints that had suffered severe damages. A similar drift of displacement before retrofitting was repeated for the specimen after being retrofitted. Visual observation of damages, hysteresis loops, stiffness, ductility and equivalent viscous damping (EVD) of the specimen were analyzed and compared before and after retrofitting. The proposed retrofitting technique has increased its lateral strength by 26%. Fewer cracks occurred after retrofitting the specimen compared to before retrofitting. It can be concluded that steel plate and angle can strengthen the wall-slab joint and this method can be used to retrofit the tunnel form building if it had been damaged caused by earthquake excitations.

scholarly journals Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai
Keyword(s):  
Near Field ◽  
Asphalt Binder ◽  
Optical Microscope ◽  
Asphalt Binders ◽  
Zero Shear Viscosity ◽  
Surface Features ◽  
Asphaltene Content ◽  
Scanning Transmission ◽  
Before And After ◽  
Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

scholarly journals Calculation of coseismic displacement from Lidar data in the 2016 Kumamoto, Japan, earthquake

2016 ◽  
Author(s):  
Luis Moya ◽  
Fumio Yamazaki ◽  
Wen Liu ◽  
Tatsuro Chiba
Keyword(s):  
Near Field ◽  
Strong Motion ◽  
Lidar Data ◽  
2016 Kumamoto Earthquake ◽  
Fault Line ◽  
Coseismic Displacement ◽  
The 2016 Kumamoto Earthquake ◽  
Surface Models ◽  
Before And After ◽  
Search Approach

Abstract. The spatial distribution of the coseismic displacements that occurred along the Futagawa fault during the 2016 Kumamoto earthquake of Mw 7.0 was estimated using airborne light detection and ranging (Lidar) data. In this study, a pair of digital surface models (DSMs) obtained from the high-density Lidar data before and after the mainshock on April 16, 2016, was used. A window matching search approach based on the correlation coefficient between the two DSMs was used to estimate the geodetic displacement in the near-field region. The results showed good agreements with the geodetic displacements calculated from strong-motion acceleration records and coincided with the fault line surveyed by the Geological Survey of Japan.

scholarly journals History, observation and mathematical models in the seismic analysis of the Valadier abutment area in the Colosseum

1995 ◽  
Vol 38 (5-6) ◽  
Author(s):  
G. Croci ◽  
D. D'Ayala ◽  
R. Liburdi
Keyword(s):  
Mathematical Models ◽  
Seismic Analysis ◽  
Numerical Models ◽  
Time History ◽  
Historical Records ◽  
Direct Integration ◽  
Structural Behaviour ◽  
Seismic Behaviour ◽  
Before And After ◽  
Xix Century

The present work aimed to outline the need to investigate different fields of research to interpret the structural behaviour of a monument as complex as the Colosseum. It is shown how defining the numerical models first. then refining them, followed by interpretation of results. is strictly linked with the inforination gathered from historical records and observation of the ~nonumenta s it is today. The study is confined to the area of the Valadier abutment. analysing its state and its seismic behaviour before and after the XIX century restoration using different ilumerical tools, from the elastic modal analysis to the non linear step by step time history direct integration. The procedure comparati\ely evaluates the reliability in the interpretation of the results and identifies future lines or research.

scholarly journals Calculation of coseismic displacement from lidar data in the 2016 Kumamoto, Japan, earthquake

2017 ◽  
Vol 17 (1) ◽  
pp. 143-156 ◽  
Author(s):  
Luis Moya ◽  
Fumio Yamazaki ◽  
Wen Liu ◽  
Tatsuro Chiba
Keyword(s):  
Near Field ◽  
Strong Motion ◽  
Lidar Data ◽  
2016 Kumamoto Earthquake ◽  
Fault Line ◽  
Coseismic Displacement ◽  
The 2016 Kumamoto Earthquake ◽  
Surface Models ◽  
Before And After ◽  
Search Approach

Abstract. The spatial distribution of the coseismic displacements that occurred along the Futagawa fault during the 2016 Kumamoto earthquake of Mw 7.0 was estimated using airborne light detection and ranging (lidar) data. In this study, a pair of digital surface models (DSMs) obtained from the high-density lidar data before and after the mainshock on 16 April 2016 were used. A window matching search approach based on the correlation coefficient between the two DSMs was used to estimate the geodetic displacement in the near-field region. The results showed good agreements with the geodetic displacements calculated from strong-motion acceleration records and coincided with the fault line surveyed by the Geological Survey of Japan.

scholarly journals NSOM/QD-Based Visualization of GM1 Serving as Platforms for TCR/CD3 Mediated T-Cell Activation

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Liyun Zhong ◽  
Zhun Zhang ◽  
Xiaoxu Lu ◽  
Shengde Liu ◽  
Crystal Y. Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Imaging System ◽  
Near Field ◽  
Cell Receptor ◽  
Dependent Manner ◽  
Receptor Complexes ◽  
Before And After

Direct molecular imaging of nanoscale relationship between T-cell receptor complexes (TCR/CD3) and gangliosidosis GM1 before and after T-cell activation has not been reported. In this study, we made use of our expertise of near-field scanning optical microscopy(NSOM)/immune-labeling quantum dots- (QD-)based dual-color imaging system to visualize nanoscale profiles for distribution and organization of TCR/CD3, GM1, as well as their nanospatial relationship and their correlation with PKCθsignaling cascade during T-cell activation. Interestingly, after anti-CD3/anti-CD28 Ab co-stimulation, both TCR/CD3 and GM1 were clustered to form nanodomains; moreover, all of TCR/CD3 nanodomains were colocalized with GM1 nanodomains, indicating that the formation of GM1 nanodomains was greatly correlated with TCR/CD3 mediated signaling. Specially, while T-cells were pretreated with PKCθsignaling inhibitor rottlerin to suppress IL-2 cytokine production, no visible TCR/CD3 nanodomains appeared while a lot of GM1 nanodomains were still observed. However, while T-cells are pretreated with PKCαβsignaling inhibitor GÖ6976 to suppress calcium-dependent manner, all of TCR/CD3 nanodomains were still colocalized with GM1 nanodomains. These findings possibly support the notion that the formation of GM1 nanodomains indeed serves as platforms for the recruitment of TCR/CD3 nanodomains, and TCR/CD3 nanodomains are required for PKCθsignaling cascades and T-cell activation

scholarly journals Muscle Coactivation Before and After the Impact Phase of Running Following Isokinetic Fatigue

2011 ◽  
Vol 46 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Eleftherios Kellis ◽  
Andreas Zafeiridis ◽  
Ioannis G. Amiridis
Keyword(s):  
Muscle Activation ◽  
Biceps Femoris ◽  
Knee Extension ◽  
Knee Extensors ◽  
Training Experience ◽  
Cross Sectional ◽  
Muscle Activation Patterns ◽  
Strength Capacity ◽  
Before And After ◽  
The Impact

Abstract Context: The effects of fatigue on impact loading during running are unclear, with some authors reporting increased impact forces and others reporting decreased forces. Objective: To examine the effects of isokinetic fatigue on muscle cocontraction ratios about the knee and ankle during running. Design: Cross-sectional study. Setting: Neuromechanics laboratory. Patients or Other Participants: Female middle-distance runners (age  =  21.3 ± 1.93 years) with at least 5 years of training experience. Intervention(s): Participants ran on the treadmill at 3.61 m/s before and immediately after the fatigue protocol, which consisted of consecutive, concentric knee extension-flexion at 120°/s until they could no longer produce 30% of the maximum knee-extension moment achieved in the familiarization session for 3 consecutive repetitions. Main Outcome Measure(s): Electromyographic (EMG) amplitude of the vastus medialis (VM), biceps femoris (BF), gastrocnemius (GAS), and tibialis anterior (TA) was recorded using surface electrodes. Agonist∶antagonist EMG ratios for the knee (VM∶BF) and ankle (GAS∶TA) were calculated for the preactivation (PR), initial loading response (LR1), and late loading response (LR2) phases of running. Hip-, knee-, and ankle-joint angular displacements at initial foot contact were obtained from 3-dimensional kinematic tracings. Results: Fatigue did not alter the VM∶BF EMG ratio during the PR phase (P > .05), but it increased the ratio during the LR1 phase (P < .05). The GAS∶TA EMG ratio increased during the LR1 phase after fatigue (P < .05) but remained unchanged during the PR and LR2 phrases (P > .05). Conclusions: The increased agonist EMG activation, coupled with reduced antagonist EMG activation after impact, indicates that the acute decrease in muscle strength capacity of the knee extensors and flexors results in altered muscle-activation patterns about the knee and ankle before and after foot impact.

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