Experimental Studies of Single-Layer Reticulated Domes with Isolated Supports

To study the seismic behavior of a single-layer reticulated dome subjected to severe earthquakes, a series of shaking table tests were conducted for this paper. Seismic responses including the acceleration, displacement, and strains gathered at the members and nodes were discussed. The dynamic characteristics, including structure frequencies and damping ratio, were obtained through the results under the input excitation of white noise and the fast sine sweeping with different amplitudes. Various isolation devices usually installed in the upper portion of the structures have been widely used to reduce the dynamic responses for more than three decades. However, these isolation devices deal mostly with either horizontal isolation or vertical isolation, which is not applicable for synchronous isolation in both horizontal and vertical isolation. Therefore, an innovative isolated support for three-dimensional isolation was invented. In order to understand the earthquake-isolation effects of a single-layer reticulated dome with the isolated support, a series of shaking table tests were conducted. The dynamic behavior of the structure was then investigated and discussed using the acceleration and displacement responses of the tested structures with or without the isolated supports. The experimental results show that the isolated support invented in this study had a remarkable earthquake-isolation action in both horizontal and vertical isolation.

Download Full-text

Experimental Studies on Earthquake Response Behavior of Cylindrical Tanks

Journal of Pressure Vessel Technology ◽

10.1115/1.3264855 ◽

1987 ◽

Vol 109 (1) ◽

pp. 50-57 ◽

Cited By ~ 3

Author(s):

H. Zui ◽

T. Shinke ◽

A. Nishimura

Keyword(s):

Seismic Behavior ◽

Experimental Studies ◽

Shaking Table ◽

Earthquake Response ◽

Test Results ◽

Dynamic Tests ◽

Shaking Table Tests ◽

Liquid Storage ◽

Cylindrical Tanks ◽

Significant Factors

A series of dynamic tests for the seismic behavior of ground-supported liquid storage tanks are evaluated and compared with previous theoretical studies. Two model tanks were subjected to shaking table tests with particular attention to the influence of base fixity and geometric imperfections in the tank walls. Test results support numerical calculations which show that base fixity conditions strongly influence the seismic response of tanks. Although high radial accelerations are induced by the imperfections, they are not found to be significant factors in tank failure.

Download Full-text

Shaking Table Tests of Suspended Structures Equipped with Viscous Dampers

Applied Sciences ◽

10.3390/app9132616 ◽

2019 ◽

Vol 9 (13) ◽

pp. 2616 ◽

Cited By ~ 3

Author(s):

Wenhua Cai ◽

Bujun Yu ◽

Sakdirat Kaewunruen

Keyword(s):

Primary Structure ◽

Damping Ratio ◽

Seismic Energy ◽

Shaking Table ◽

Dynamic Responses ◽

Strain Response ◽

Peak Acceleration ◽

Shaking Table Tests ◽

Viscous Dampers ◽

Suspended Structure

In this study, a series of shaking table tests of a ten storey concrete suspended structure equipped with viscous dampers were carried out to evaluate the dynamic responses and vibration damping performance of suspended structures. The effects of link types between the primary structure and suspended floors and different seismic excitations on the response of suspended structure models was verified. The responses include the damping ratio, the frequency, maximum relative displacements, accelerations and maximum strains of the suspended structures. Test results showed that the damping ratio and the frequency of suspended structures installed with dampers (called damping suspended structure) are adjusted compared with a conventional suspended structure with rigid-bar links (conventional suspended structure). Maximum relative displacements of the primary structure of the damping suspended structure were distinctly smaller than those of the conventional suspended structure. However, the maximum relative displacement between the primary structure and the suspended floors of the damping suspended structure was significantly larger than that of the conventional structure, indicating that the swing of the suspended floor can help dissipate seismic energy. The peak acceleration and acceleration amplification factors of the damping suspended structure were less than the conventional suspended structure. Moreover, the peak acceleration response of the damping suspended structure was slightly behind the conventional suspended structure. The damping suspended structure certainly had a considerable and stable reduction for strain response, and the maximum strain response was decreased by 42.3%–72.7% for the damping suspended structure compared with the conventional suspended structure.

Download Full-text

Seismic Response of Pile Groups Improved with Deep Cement mixing Columns in Liquefiable Sand: Shaking Table Tests

Canadian Geotechnical Journal ◽

10.1139/cgj-2020-0505 ◽

2021 ◽

Author(s):

Dingwen Zhang ◽

Anhui Wang ◽

Xuanming Ding

Keyword(s):

Seismic Behavior ◽

Lateral Displacement ◽

Bending Moment ◽

Pile Group ◽

Shaking Table ◽

Excess Pore Pressure ◽

Shaking Table Tests ◽

Pile Groups ◽

Acceleration Response ◽

Table Model

A series of shaking table model tests were performed to examine the effects of deep cement mixing (DCM) columns with different reinforcement depths on the seismic behavior of a pile group in liquefiable sand. Due to the DCM column reinforcement, the fundamental natural frequency of the model ground increases noticeably. The excess pore pressure of soils reduces with the increase of reinforcement depths of the DCM columns. Before liquefaction, the acceleration response of soils in the improved cases is obviously lower than that in the unimproved case, but the acceleration attenuation is greater after liquefaction in the unimproved case. Moreover, the lateral displacement of the superstructure, the settlement of the raft, and the bending moment of the piles in the improved cases are significantly reduced compared to those in the unimproved case, and the reduction ratios rise with the increase of reinforcement depth of the DCM columns. However, reinforcement by the DCM columns may result in the variation of the location of the maximum moment that occurs in the pile.

Download Full-text

Influence of Structure on the Aseismic Stability and Dynamic Responses of Liquefiable Soil

10.21203/rs.3.rs-312945/v1 ◽

2021 ◽

Author(s):

Pengfei Dou ◽

Chengshun Xu ◽

Xiuli Du ◽

Su Chen

Keyword(s):

Earthquake Engineering ◽

Damping Ratio ◽

Free Field ◽

Shaking Table ◽

Dynamic Responses ◽

Seismic Stability ◽

Geotechnical Earthquake Engineering ◽

Liquefiable Soil ◽

Porewater Pressure ◽

Lateral Displacements

Abstract In previous major earthquakes, the damage and collapse of structures located in liquefied field which caused by site failure a common occurrence, and the problem of evaluation and disscusion on site liquefaction and the seismic stability is still a key topic in geotechnical earthquake engineering. To study the influence of the presence of structure on the seismic stability of liquefiable sites, a series of shaking table tests on liquefiable free field and non-free field with the same soil sample was carried out. It can be summarized from experimental results as following. The natural frequency of non-free field is larger and the damping ratio is smaller than that of free field. For the weak seismic loading condition, the dynamic response of sites show similar rules and trend. For the strong ground motion condition, soils in both experiments all liquefied obviously and the depth of liquefaction soil in the free field is significantly greater than that in the non-free field, besides, porewater pressure in the non-free field accumulated relately slow and the dissapited quikly from analysis of porewater pressure ratios(PPRs) in both experiments. The amplitudes of lateral displacements and acceleration of soil in the non-free field is obviously smaller than that in the free field caused by the effect of presence of the structure. In a word, the presence of structures will lead to the increase of site stiffness, site more difficult to liquefy, and the seismic stability of the non-free site is higher than that of the free site due to soil-structure interaction.

Download Full-text

Shaking table tests on seismic behavior of the underground loess cave of earth building of traditional dwellings

Engineering Structures ◽

10.1016/j.engstruct.2020.110221 ◽

2020 ◽

Vol 207 ◽

pp. 110221

Author(s):

Jianyang Xue ◽

Xiangbi Zhao ◽

Fengliang Zhang ◽

Dan Xu ◽

Xiaofeng Hu ◽

...

Keyword(s):

Seismic Behavior ◽

Shaking Table ◽

Shaking Table Tests

Download Full-text

Investigation on Seismic Behavior of Recycled Aggregate Concrete Structures under Dynamic Loadings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.772.149 ◽

2013 ◽

Vol 772 ◽

pp. 149-155

Author(s):

Chang Qing Wang

Keyword(s):

Seismic Behavior ◽

Fatigue Behavior ◽

Experimental Studies ◽

Concrete Structures ◽

Recycled Aggregate Concrete ◽

Shaking Table ◽

Frame Structure ◽

Recycled Aggregate ◽

Scale Model ◽

Aggregate Concrete

Based on the ever finished investigations of physical and mechanical properties of recycled aggregate concrete (RAC), and a series of experimental studies on the durability, the fatigue behavior, mechanical behavior and the seismic behavior of RAC components. A full scale model of a one-storey block masonry structure with tie column + ring beam + cast-in-place slab system and a one fourth scaled model of a 6-storey frame structure, which are made of reinforced recycled aggregate concrete, are tested on a shaking table by subjecting it to a series of simulated seismic ground motions, and the seismic behaviors of the RAC structures were experimentally investigated. The dynamic characteristics and the seismic response were analyzed and discussed. The overall seismic performance of RCA structures are evaluated, the analysis results show that the recycled aggregate concrete structures with proper design exhibits good seismic behavior and can resist the earthquake attacks under different earthquake levels in this study. It is feasible to apply and popularize the RAC block masonry buildings less than 2 stories and the RAC frame buildings less than 6 stories in the region where the seismic fortification intensity is 8.

Download Full-text