Monotonic and Cyclic Responses of Plastic Concrete Cores Used in Embankment Dams

Mojtaba Daei¹ Ehsan Dadkhah² Mohammad Kheirollah³

1) Civil engineering department, University of Tabriz, Tabriz ,Iran.
2) Department of Civil Engineering, University of Tabriz, Ph.D Student of Earthquake Engineering, Tabriz, Iran,
3) Department of Civil Engineering, Sahand University of Technology, Tabriz, Iran, Ph.D Student of Structural Engineering,

محل انتشار : دومین کنفرانس بین المللی ژئوتکنیک و مهندسی لرزه ای(icguee.ir)
چکیده :
The dynamic properties of plastic concrete used as an alternative core in embankment dams were studied. To investigate the specimen’s dynamic properties, an extensive series of monotonic and cyclic triaxial tests were done. Bentonitecontents 5.5%, 6.0%, 6.5% and 7.0% were selected for the tests. Isotropic and anisotropic initial stress conditions with various principal stress ratios were also considered in this study. Thousands of cycles were applied on some of the specimens, to evaluate their fatigue properties due to seismic loading. A small degradation could be seen but no cracking was observed on the cutting surfaces. All tests were done at a constant temperature of 10 ˚C simulating a constant temperature inside a dam in cold regions. Shear modulus in the compression region (Gc) and tension region (Ge) are presented for different bentonite content, confining stress, stress ratio (Kc) and loading type. The damping ratio was also presented for different loading states. A regression equation was also derived for determining cyclic and maximum shear modulus (Gmax) of the plastic concrete for different bentonite content as a function of confining stress which can be used in numerical studies.
کلمات کلیدی : Plastic concrete materials, Embankment dams, Monotonic and cyclic tests, bentoniteratio, dynamic properties, Shear modulus, Damping ratio