scholarly journals Dynamic Behavior of Ground Improved Using a Crushed Stone Foundation Wall

2019 ◽  
Vol 11 (10) ◽  
pp. 2767
Author(s):  
Su-Won Son ◽  
Pouyan Bagheri ◽  
Jin-Man Kim
Keyword(s):  
Dynamic Behavior ◽  
Shaking Table Test ◽  
Soft Soil ◽  
Shaking Table ◽  
Crushed Stone ◽  
Natural Period ◽  
Long Period ◽  
Acceleration Amplification ◽  
Short Period ◽  
Foundation Wall

The improvement of soft clay and dredged soils to carry structures is increasingly important. In this study, the dynamic behavior of a crushed stone foundation wall in clay soil was analyzed using a 1g shaking table test. The response accelerations and spectra for three input ground motions were analyzed relative to the distance from the foundation wall, confirming that the acceleration was damped from the outside. The acceleration according to the distance from the wall was not significant under long-period motions, while different responses were obtained under short-period motions. The increased ground stiffness provided by the crushed stone wall lowered the natural period of the ground, and the acceleration amplification under short-period seismic waves was larger than that under long-period waves. Finally, equations were derived to describe the relationship between the acceleration amplification ratio and distance from the wall. The slopes of the proposed equations are larger under shorter periods, implying that the change in acceleration change with distance from the wall is more significant under shorter periods. The results of this study can be used to inform the design of soft soil improvements and the structures built atop them.

Study on TMD for Long Period Structure Using Air Floating Technique: Investigation of Fundamental Performance

2018 ◽  
Author(s):  
Osamu Furuya ◽  
Hiroshi Kurabayashi ◽  
Osamu Takahashi ◽  
Kunio Sanpei ◽  
Shoichi Sakamoto ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Shaking Table Test ◽  
Structural Response ◽  
Shaking Table ◽  
Inertia Force ◽  
Loading Test ◽  
Natural Period ◽  
Long Period ◽  
Static Loading Test

Natural period of architectural structure have been longer to be high-rise in recent years. Tuned Mass Damper (TMD) is applied for the structural response reduction in such a long period structure. In general since there are a lot of design cases using a guide rail for linear motion guide of the mass in TMD, the friction coefficient in assembled TMD becomes almost from 3/1000 to 5/1000. The friction coefficient leads an important problem in view point of performance design for long period structures because of that the friction force becomes a large compared with starting inertia force. In this study, new type TMD with air pressure floating technique has been examined to reduce a friction force for starting inertia force, and to set 0.01 m/s2 in starting acceleration as a performance target. This paper shows the evaluation results for fundamental performance from static loading test and shaking table test.

Study on Dynamic Behavior of Ancient Timber Structures Roof

2013 ◽  
Vol 475-476 ◽  
pp. 1559-1562
Author(s):  
Jun Dai
Keyword(s):  
Dynamic Behavior ◽  
Vibration Isolation ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Maximal Response ◽  
Construction Technology ◽  
Magnification Factor ◽  
Finite Element Software ◽  
Moderate Earthquake ◽  
Dynamic Magnification Factor

The roof model of the palace timber buildings was established according to the construction technology of the Ying-tsao fa-shih. Based on its analysis of dynamic behavior with shaking table test and ANSYS finite element software, the dynamic behavior of structure and its maximal response under different conditions were gotten, and also the dynamic magnification factor of the beams layer and the whole structure were gotten, at last the results got by shaking table test was compared with the numerical simulation. Research shows that the nature frequency of the model is 1.486 Hz which is much bigger than that of the whole structure; the maximal displacement of beam layer gradually increases with the increase of ground motion intensity and the height of structure; the vibration isolation performance of semi-rigid tenon-mortise joints in rare earthquake (400gal) is better than that in moderate earthquake (220gal) and frequent earthquake (110gal); the dynamic magnification factor between layers was about 1, and roof 0.9 or so.

Shaking Table Test Study on Mid-Story Isolation Structures

2012 ◽  
Vol 446-449 ◽  
pp. 378-381
Author(s):  
Jian Min Jin ◽  
Ping Tan ◽  
Fu Lin Zhou ◽  
Yu Hong Ma ◽  
Chao Yong Shen
Keyword(s):  
Seismic Response ◽  
Seismic Isolation ◽  
Shaking Table Test ◽  
Base Isolation ◽  
Shaking Table ◽  
Natural Period ◽  
Isolation System ◽  
Isolation Layer ◽  
Lead Rubber Bearing ◽  
Complex Structural

Mid-story isolation structure is developing from base isolation structures. As a complex structural system, the work mechanism of base isolation structure is not entirely appropriate for mid-story isolation structure, and the prolonging of structural natural period may not be able to decrease the seismic response of substructure and superstructure simultaneously. In this paper, for a four-story steel frame model, whose prototype first natural period is about 1s without seismic isolation design, the seismic responses and isolation effectiveness of mid-story isolation system with lead rubber bearing are studied experimentally by changing the location of isolation layer. Respectively, the locations of isolation layer are set at bottom of the first story, top of the first story, top of the second story and top of the third story. The results show that mid-story isolation can reduce seismic response in general, and substructure acceleration may be amplified.

Seismic Mitigation Assessment of Building Using Multiple Direction Optimized-Friction Pendulum System

2008 ◽  
Author(s):  
C. S. Tsai ◽  
Wen-Shin Chen ◽  
Yung-Chang Lin ◽  
Chi-Lu Lin
Keyword(s):  
Finite Element ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Natural Period ◽  
Pendulum System ◽  
Friction Pendulum ◽  
Seismic Mitigation ◽  
Friction Pendulum System

In order to prevent a building near a fault from earthquake damage, in this study an advanced base isolation system called the multiple direction optimized-friction pendulum system (Multiple DO-FPS or MDO-FPS) is proposed and examined to address its mechanical behavior through the finite element formulation and evaluate its efficiency in seismic mitigation through a series of shaking table tests. On the basis of the finite element formulation, it is revealed that the natural period, the capacity of the bearing displacement and damping effect for the Multiple Direction Optimized-Friction Pendulum System (Multiple DO-FPS) change continually during earthquakes. Therefore, the MDO-FPS isolator can avoid possibility of resonance of enriched frequencies from ground motions and provide an efficient capacity of the bearing displacement and damping during the earthquakes. Simultaneously, the shaking table test results also illustrate that the Multiple DO-FPS isolator possesses an outstanding seismic mitigation capabilities.

scholarly journals Seismic Response of a Bridge Pile Foundation during a Shaking Table Test

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Yunxiu Dong ◽  
Zhongju Feng ◽  
Jingbin He ◽  
Huiyun Chen ◽  
Guan Jiang ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Pile Foundation ◽  
Large Scale ◽  
Amplification Factor ◽  
Shaking Table Test ◽  
Seismic Intensity ◽  
Shaking Table ◽  
Acceleration Amplification ◽  
Bedrock Surface ◽  
Bridge Pile Foundation

Puqian Bridge is located in a quake-prone area in an 8-degree seismic fortification intensity zone, and the design of the peak ground motion is the highest grade worldwide. Nevertheless, the seismic design of the pile foundation has not been evaluated with regard to earthquake damage and the seismic issues of the pile foundation are particularly noticeable. We conducted a large-scale shaking table test (STT) to determine the dynamic characteristic of the bridge pile foundation. An artificial mass model was used to determine the mechanism of the bridge pile-soil interaction, and the peak ground acceleration range of 0.15 g–0.60 g (g is gravity acceleration) was selected as the input seismic intensity. The results indicated that the peak acceleration decreased from the top to the bottom of the bridge pile and the acceleration amplification factor decreased with the increase in seismic intensity. When the seismic intensity is greater than 0.50 g, the acceleration amplification factor at the top of the pile stabilizes at 1.32. The bedrock surface had a relatively small influence on the amplification of the seismic wave, whereas the overburden had a marked influence on the amplification of the seismic wave and filtering effect. Damage to the pile foundation was observed at 0.50 g seismic intensity. When the seismic intensity was greater than 0.50 g, the fundamental frequency of the pile foundation decreased slowly and tended to stabilize at 0.87 Hz. The bending moment was larger at the junction of the pile and cap, the soft-hard soil interface, and the bedrock surface, where cracks easily occurred. These positions should be focused on during the design of pile foundations in meizoseismal areas.

Shaking Table Test of Quarter Scale 20 Story RC Moment Frame Building Subjected to Long Period Ground Motions

2016 ◽  
Vol 11 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Kuniyoshi Sugimoto ◽  
◽  
Kenji Yonezawa ◽  
Hideo Katsumata ◽  
Hiroshi Fukuyama ◽  
...  
Keyword(s):  
Shaking Table Test ◽  
Shaking Table ◽  
Test Results ◽  
Nonlinear Fem ◽  
Moment Frame ◽  
Building Model ◽  
Long Period ◽  
Frame Building ◽  
Long Duration ◽  
Current Design

Shaking table test of a quarter-scale 20-story reinforced concrete building model was carried out. Employed input waves were kinds of long period and long duration ground motion. Test results showed that structural slabs were fully effective for building strength, which could be expressed in detailed analysis using nonlinear FEM. However, the observed hysteretic damping after yielding was fairly smaller than the expected by the current design custom, which caused smaller and unsafe estimated response than that observed in the test.

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.

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