An innovative resilient rocking column with replaceable steel slit dampers: Experimental program on seismic performance

2019 ◽  
Vol 183 ◽  
pp. 830-840 ◽  
Author(s):  
Yang Liu ◽  
Zixiong Guo ◽  
Xiaojuan Liu ◽  
Rachel Chicchi ◽  
Bahram Shahrooz
Keyword(s):  
Seismic Performance ◽  
Experimental Program ◽  
Rocking Column

Shaking Table Test on Unreinforced Stone Masonry Pagoda

2012 ◽  
Vol 166-169 ◽  
pp. 730-733 ◽  
Author(s):  
Fei Zhu ◽  
Feng Lai Wang ◽  
Xu Jie Sun ◽  
Y. Zhao
Keyword(s):  
Dynamic Behavior ◽  
Seismic Performance ◽  
Seismic Design ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Cultural Value ◽  
Scale Model ◽  
Stone Masonry ◽  
Experimental Program ◽  
Ancient China

Unreinforced stone masonry pagodas have great cultural value and should be detailed investigation its mechanical properties. These buildings were not designed to resist earthquakes in ancient China, at least not in the way of current methods. The objectives of this research were to understand the dynamic behavior of unreinforced stone masonry pagoda and its seismic performance. To accomplish these, a 1/12 scale model of China Dinosaurs Pagoda was constructed and tested on shaking table. The octangle model height is 3.96m, with aspect ratio of height to width is 2.93, both parameters exceed the stipulated limit of Code for Seismic Design of Building. The model built with the stones and motars similar to the prototype materials and the arrangements. Its dynamic behavior and seismic performance were tested on the shaking table towards the free vibration and three earthquake waves. The experimental program adopted in the research is explained in this paper.

Experimental Research on Seismic Performance of Pre-Damaged RC Frame T-Beam Strengthened with Sprayed BFRP

2014 ◽  
Vol 507 ◽  
pp. 209-216 ◽  
Author(s):  
Rui Gao ◽  
Qian Gu ◽  
Cheng Fang Sun ◽  
Yu Jia Peng
Keyword(s):  
Seismic Performance ◽  
Peak Load ◽  
Basalt Fiber ◽  
Experimental Program ◽  
Rc Frame ◽  
Reinforcement Effect ◽  
Cyclic Shear ◽  
Shear Loads ◽  
Reinforced Polymer ◽  
T Beam

This experimental program was designed for investigating the seismic performance and reinforcement effect of pre-damaged RC frame T-beams reinforced with sprayed basalt fiber reinforced polymer (BFRP). Four RC frame T-shape beams specimens, among which one was unstrengthened , one was undamaged and strengthened , and the other two were pre-damaged and strengthened, were tested under an incremental loading procedure of the pseudo-static, cyclic shear loads. The test results including the failure mode, ultimate bearing capacity, load-displacement hysteresis curves and ductility of specimens were obtained and analyzed. It indicates that spraying BFRP reinforcement can effectively increase the peak load and energy dissipation performance of damaged RC frame T-beams, ultimate lateral deformation and ductility of damaged RC frame T-beams can be improved obviously. Increasing the reinforcement thickness of sprayed BFRP can effectively improve the seismic reinforcement effect of T-shaped beams damaged by the earthquake.

scholarly journals Seismic Performance of LRS-FRP–Concrete–Steel Tubular Double Coupling Beam

2021 ◽  
Vol 11 (5) ◽  
pp. 2024
Author(s):  
Lili Sui ◽  
Yanlei Liu ◽  
Zhongfeng Zhu ◽  
Biao Hu ◽  
Cheng Chen ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Steel Tube ◽  
Peak Strength ◽  
Experimental Program ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Initial Stiffness ◽  
Double Coupling ◽  
Frp Sheet

To improve the ductility and seismic performance of a double coupling beam, the authors applied a polyethylene terephthalate (PET) sheet and steel tube to form fiber-reinforced polymer (FRP)–concrete–steel double-skin tubular (DST) composite coupling beams. A low-cyclic reversed experimental program was carried out which factored in the member form, steel tube diameter, and construction methods. The results indicate that the ductility and energy dissipation performance of double coupling beams—whether wrapped with a PET-FRP sheet or surrounded by an FRP–concrete–steel DST composite system—is a substantial improvement over the traditional reinforced-concrete double coupling beam (RC-DCB). The ductility coefficient and accumulated energy dissipation of the DST-DCB members improved above 170% and 2300%, respectively. These percentages compare to the RC-DCB and are based on the rupture of a PET-FRP sheet. The results are similar to those of the large rupture strain double coupling beam (LRS-DCB). Meanwhile, the external wrapped PET-FRP sheet does not affect the initial stiffness and peak strength of the RC-DCB. Relatively, the inner steel tube will improve the initial stiffness, yielding strength, and peak strength. DST-DCB members still have considerable deformability after 85% of peak strength since the external PET-FRP sheet provided an effective constraint effect on the core concrete and the inner steel tube could bear excellent shear deformation.

Seismic assessment of rainscreen stucco systems

2008 ◽  
Vol 35 (4) ◽  
pp. 358-369
Author(s):  
Mehdi H.K. Kharrazi ◽  
Graham W. Taylor ◽  
Carlos E. Ventura
Keyword(s):  
Seismic Performance ◽  
Experimental Program ◽  
Dynamic Tests ◽  
Structural Behaviour ◽  
Static Tests ◽  
Frame Buildings ◽  
Air Space ◽  
Static And Dynamic Tests ◽  
Wood Frame ◽  
Frame Construction

This paper evaluates the comparative and absolute in-plane seismic performance of rainscreen and nonrainscreen stucco exterior cladding systems for residential wood frame construction in British Columbia. In this study, an experimental program including quasi-static and dynamic tests was implemented, comprised of 18 (in-plane) quasi-static tests and two dynamic tests. The principal parameters investigated in this study were type of strapping, type and length of strapping fastener, and type and length of lath fastener. All rainscreen specimens were constructed with a 20 mm air space. The overall conclusion is that both rainscreen and nonrainscreen stucco comply with the code requirements addressing the permissible drifts. Therefore, both stucco systems were found to improve the structural behaviour when used as the lateral resisting system of residential wood frame buildings. This paper concludes with recommendations for seismic refinements to current construction practices.

Shaking Table Test on Seismic Performance of L- and V-Sectioned Reinforced Concrete Columns

2015 ◽  
Vol 09 (04) ◽  
pp. 1550010
Author(s):  
Xuan-Huy Nguyen ◽  
Xuan-Dat Pham ◽  
Xuan-Chieu Luong
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Shaking Table Test ◽  
Absorption Capacity ◽  
Shaking Table ◽  
Experimental Program ◽  
Ground Acceleration ◽  
Cross Sectional ◽  
Response Characteristics ◽  
Current Test

This paper presents an experimental program to investigate the effects of cross-sectional shape on the seismic performance of irregularly shaped reinforced concrete (RC) columns. Five groups of specimens that were one-quarter of typical columns of a prototype medium-rise building were tested to failure using shaking table. The loading procedure was successively increasing peak ground acceleration until the test structure collapsed. The specimens were designed with the same cross-section area but different flange width and flange thickness. The seismic response characteristics of all specimens such as drift capacity, energy absorption capacity and failure mechanisms of each specimen group are evaluated, compared and discussed in detail. Based on the current test data, design recommendation is provided to assist engineers in designing such irregularly shaped columns.

scholarly journals Experimental Study on Seismic Behavior of Masonry Walls Strengthened by Reinforced Mortar Cross Strips

2019 ◽  
Vol 11 (18) ◽  
pp. 4866 ◽  
Author(s):  
Dong ◽  
Sui ◽  
Jiang ◽  
Zhou
Keyword(s):  
Seismic Performance ◽  
Cyclic Load ◽  
Failure Modes ◽  
Shear Failure ◽  
Constant Load ◽  
Shear Capacity ◽  
Experimental Program ◽  
Test Results ◽  
Reinforced Masonry ◽  
Key Factor

Due to the poor seismic performance, strengthening of masonry structures is always a significant problem worthy to study. It has been proven that the bearing capacity of existing masonry buildings can be enhanced greatly with efficient strengthening measures. An experimental program was conducted to investigate seismic performance of un-reinforced masonry (URM) walls strengthened b,y reinforced mortar (RM) cross strips. Eleven walls were tested under horizontal low-cyclic load, simultaneously with a vertical constant load on the top face. Three URM walls were tested as reference. The other eight walls were externally strengthened with 40 and 60 mm thick of RM cross strips on one or both faces. Test results showed that externally strengthening with RM cross strips was an efficient way to enhance the seismic performance of URM walls. The failure modes were divided into shear failure and shear-compression failure. All the tested walls did not collapse until the test ended, while many diagonal cracks and few vertical cracks appeared on mortar strips. After strengthening, the shear capacity of the strengthened walls increased by at least 38.2%, and the reinforcement ratio was noted to be the key factor to influence the shear capacity with positive correlation. Besides, RM cross strips did improve deformation capacity greatly.

Seismic Rehabilitation of a Three-Storey R/C Flat-Slab Prototype Structure Using Different Techniques

2012 ◽  
Vol 193-194 ◽  
pp. 1346-1351 ◽  
Author(s):  
Marco Valente
Keyword(s):  
Seismic Performance ◽  
Numerical Study ◽  
Numerical Models ◽  
Experimental Program ◽  
Eurocode 8 ◽  
Seismic Behaviour ◽  
Earthquake Intensity ◽  
Flat Slab ◽  
Performance Improvements ◽  
Prototype Structure

This paper presents some results of a numerical study on the seismic performance and retrofitting of a R/C flat-slab prototype structure. The study was based on an experimental program carried out at the JRC ELSA Laboratory with the aim of assessing the seismic behaviour of flat-slab structures. Numerical models of the test structure were developed and nonlinear static and dynamic analyses were carried out. Two seismic retrofit techniques were numerically simulated to enhance the seismic performance of the structure. First the structure was rehabilitated by concrete jacketing of columns with added longitudinal and transverse reinforcement. The second intervention was based on confinement of column ends by using FRP wrapping. The results of this study provide information about the seismic performance of a common type of R/C structure not covered by the provisions of Eurocode 8, as well as the potential to mitigate the expected damage for varying earthquake intensity through retrofit. The comparison of the overall seismic response of the bare and rehabilitated structures showed the seismic performance improvements provided by the retrofitting interventions.

Monotonic and cyclic load behaviour of helical pile connectors in the vertical direction

2006 ◽  
Vol 33 (1) ◽  
pp. 10-18 ◽  
Author(s):  
M A Youssef ◽  
M H El Naggar ◽  
M Ahmed
Keyword(s):  
Seismic Performance ◽  
Cyclic Load ◽  
Vertical Direction ◽  
Experimental Program ◽  
Seismic Resistance ◽  
Element Analysis ◽  
Existing Structures ◽  
Attractive Option ◽  
Loading Modes ◽  
The University

The helical pile is a foundation system that is used to support new residential and commercial buildings and to stabilize repairs of existing structures. It represents an attractive option to upgrade the seismic resistance of foundations. This necessitates a good understanding of the seismic performance of the specialized connectors linking the pile shaft to the concrete foundation. An experimental program is initiated at The University of Western Ontario to investigate the seismic performance of these connectors, to develop models that can be used in finite element analysis to describe their behaviour, and to propose modifications to enhance their seismic performance, if necessary. In this program, eight specimens were tested to assess the behaviour of two types of these connectors under different loading modes. It was concluded that connectors with an uplift bracket are required for seismic applications to control uplift displacement due to rocking of the foundation.Key words: helical pile, connector, experimental, model, monotonic load, cyclic load, foundation, stiffness, strength.

The 1-MeV Electron Microscope Installation at the University of Colorado

1973 ◽  
Vol 31 ◽  
pp. 8-9 ◽  
Author(s):  
Mircea Fotino
Keyword(s):  
Electron Microscopy ◽  
Developmental Biology ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
National Institutes Of Health ◽  
Experimental Program ◽  
University Of Colorado ◽  
Transmission Electron ◽  
The University ◽  
Research Resources

A new 1-MeV transmission electron microscope (Model JEM-1000) was installed at the Department of Molecular, Cellular and Developmental Biology of the University of Colorado in Boulder during the summer and fall of 1972 under the sponsorship of the Division of Research Resources of the National Institutes of Health. The installation was completed in October, 1972. It is installed primarily for the study of biological materials without many of the limitations hitherto unavoidable in standard transmission electron microscopy. Only the technical characteristics of the installation are briefly reviewed here. A more detailed discussion of the experimental program under way is being published elsewhere.

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