• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1233-1240
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• 2005

As the geotechnical technologies have grown, the size of civil structures has become bigger than before, thereby requiring large-scale geotechnical testing equipments which can evaluate the mechanical behavior of large size testing materials such as gravel, crushed rock and so on. These kind of large testing equipments are usually used to evaluate the mechanical characteristics of large size material which are applied in the large infra structures like dam, seashore structure, coastal landfill, soil-structure interaction and seismic response of large-scale structure. In this research, state-of-the-art information in the field of geotechnical engineering was collected and summarized for such large-scale experimental equipments as large-scale geo-centrifuge, large-scale triaxial testing machine, large-scale direct shear testing apparatus and large-scale oedometer.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1415-1424
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• 2009

Measuring dynamic properties of gravel-sized materials demands large specimens. Due to the difficulties in experiment as well as equipment, the dynamic properties of gravel-sized material has rarely been investigated. To realize free-free end condition more properly and stabilize specimen during testing with new specimen support system, a free-free resonant column testing device, which is capable of testing gravel-sized materials and constraining a specimen in free-free boundaries, is developed. We report the calibration of the equipment and preliminary testing results on Jumunjin sand. The testing data are compared with the previous data obtained from the existing fixed-free resonant column test.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.626-633
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• 2009

A large scale resonant column testing equipment is under development. The would-be equipment is aiming to test 150mm-diameter specimens, which can contain as large a grain size as 25mm. Such a large specimen is hardly excitated with the existing fixed-free end condition because the torsional force cannot be effectively coupled to the specimen. The specimen will be rather resonated with free-free condition and the scheme is implemented with a rotational bearing installed between coil-magnet exciter and base pedestal. Presently the equipment was assembled and is under calibration with a cylindrical brass specimen.

• Geomechanics and Engineering
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• v.4 no.4
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• pp.251-262
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• 2012

Triaxial tests are essential to estimate the shear strength properties of the soil or rock. Normally triaxial tests are carried out on samples of 38 mm diameter and 76 mm height. Granular materials, predominantly used in base/sub-base construction of pavements or in railways have size range of 60-75 mm. Determination of shear strength parameters of those materials can be made possible only through triaxial tests on large diameter samples. This paper describes a large diameter cyclic triaxial testing facility set up in the Geotechnical Engineering lab of Indian Institute of Science. This setup consists of 100 kN capacity dynamic loading frame, which facilitates testing of samples of up to 300 mm diameter and 600 mm height. The loading ram can be actuated up to a maximum frequency of 10 Hz, with maximum amplitude of 100 mm. The setup is capable of carrying out static as well as dynamic triaxial tests under isotropic, anisotropic conditions with a maximum confining pressure of 1 MPa. Working with this setup is a difficult task because of the size of the sample. In this paper, a detailed discussion on the various problems encountered during the initial testing using the equipment, the ideas and solutions adopted to solve them are presented. Pilot experiments on granular sub-base material of 53 mm down size are also presented.

• Structural Engineering and Mechanics
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• v.30 no.3
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• pp.331-350
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• 2008

A framework for multi-platform analytical and multi-component hybrid (testing-analysis) simulations is described in this paper and illustrated with several application examples. The framework allows the integration of various analytical platforms and geographically distributed experimental facilities into a comprehensive pseudo-dynamic hybrid simulation. The object-oriented architecture of the framework enables easy inclusion of new analysis platforms or experimental models, and the addition of a multitude of auxiliary components, such as data acquisition and camera control. Four application examples are given, namely; (i) multi-platform analysis of a bridge with soil and structural models, (ii) multiplatform, multi-resolution analysis of a high-rise building, (iii) three-site small scale frame hybrid simulation, and (iv) three-site large scale bridge hybrid simulation. These simulations serve as illustrative examples of collaborative research among geographically distributed researchers employing different analysis platforms and testing equipment. The versatility of the framework, ease of including additional modules and the wide application potential demonstrated in the paper provide a rich research environment for structural and geotechnical engineering.