scholarly journals Centrifuge Testing of Circular and Rectangular Embedded Structures with Base Excitations

2019 ◽  
Vol 35 (3) ◽  
pp. 1485-1505
Author(s):  
Elnaz Esmaeilzadeh Seylabi ◽  
Eva Agapaki ◽  
Dimitris Pitilakis ◽  
Scott Brandenberg ◽  
Jonathan P. Stewart ◽  
...  
Keyword(s):  
Design Method ◽  
Shaking Table ◽  
Flexible Pipe ◽  
Dense Sand ◽  
Centrifuge Testing ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Embedded Structures ◽  
Lateral Displacements ◽  
Experimental Findings

We present data and metadata from a centrifuge testing program that was designed to investigate the seismic responses of buried circular and rectangular culverts. The specimen configurations were based on Caltrans Standard Plans, and the scope of research was to compare the experimental findings with the design method described in the NCHRP Report 611 as well as to formulate preliminary recommendations for Caltrans practice. A relatively flexible pipe and a stiff box-shaped specimen embedded in dense sand were tested in the centrifuge at the Center for Geotechnical Modeling at University of California, Davis and were subjected to a set of broadband and harmonic input motions. Responses were recorded in the soil and in the embedded structures using a dense array of instruments. Measured quantities included specimen accelerations, bending strains, and hoop strains; soil accelerations, shear-wave velocities, settlements, and lateral displacements; and accelerations of the centrifuge's shaking table. This data paper describes the tests and summarizes the generated data, which are archived at DesignSafe.ci.org (DOI: 10.17603/DS2XW9R) and are accessible through an interactive Jupyter notebook.

Soil moisture assessment by means of compressional and shear wave velocities: Theoretical analysis and experimental setup

Measurement ◽  
2010 ◽  
Vol 43 (3) ◽  
pp. 344-352 ◽  
Author(s):  
F. Adamo ◽  
F. Attivissimo ◽  
L. Fabbiano ◽  
N. Giaquinto ◽  
M. Spadavecchia
Keyword(s):  
Soil Moisture ◽  
Theoretical Analysis ◽  
Shear Wave ◽  
Experimental Setup ◽  
Wave Velocities ◽  
Shear Wave Velocities

Multi Mode Vibration Control and Broder Band Motion Control of Three Dimensional Shaking Table

2005 ◽  
Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Equation System ◽  
State Equation ◽  
Shaking Table ◽  
Mode Vibration ◽  
And Control

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.

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

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.

scholarly journals Geophysical and geotechnical factors in urban planing: Bursa (Nilüfer, Osmangazi, and Yildirim) cases

2020 ◽  
Author(s):  
Ferhat Özçep ◽  
Guldane Boyraz ◽  
Okan Tezel ◽  
Hakan Alp ◽  
Nuray Alpaslan ◽  
...  
Keyword(s):  
Ground Motion ◽  
Hazard Analysis ◽  
Earthquake Hazard ◽  
Cyclic Stress ◽  
Soil Liquefaction ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Earthquake Motion ◽  
Potential Index ◽  
Earthquake Hazard Analysis

Abstract. The study area covers the Central of Bursa, Osmangazi, Yildirim, Gürsü, Kestel and Nilüfer District boundaries in Bursa. The seismic process deals with the occurrence of an earthquake event and the process of wave propagation from the source to the site. Local amplification caused by surficial soft soils is a significant factor in destructive earthquake motion. In the first phase of this study, it is investigated the ground motion level and soil amplifications for Bursa city. For his aim, probabilistic and deterministic earthquake hazard analysis (including acceleration estimations) will be carried out for the region. Local amplification caused by surficial soft soils is a significant factor in destructive earthquake motion. In the first phase of this study, it is investigated the ground motion level and soil acharacterization for the region. For his aim, probabilistic earthquake hazard analysis (including acceleration estimations) was carried out for the region. Then, soil shear wave velocities were estimated from data obtained by MASW measurements. Soil liquefaction is a natural event in which the strength and stiffness of a soil are reduced by earthquake vibrations or other dynamic loadings. As it is known, liquefaction occurs in saturated soils, that is, soils in which the space between individual particles is completely filled with water. One of liquefaction evaluation methods is based on the cyclic stress approach. In this method, a safety factor is defined as CRR/CSR. CRR is a cyclic resistance ratio that represents soil liquefaction susceptibility, and CSR is the cyclic stress ratio that represents the earthquake effect. In the second phase of this study, possible soil potential index (PL) and ground induced settlements were estimated by using Isihara ve Yoshimine (1990) approach. All results on liquefaction potential index (Pl), liquefaction induced settlements and soil shear wave velocities in Bursa (Turkey) City were compared with each other. Finally, a seismic microzonation map was prepared by the integration of geophysical and geotechnical data for urban planning purposes.

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