Centrifuge Modeling Studies of Site Response in Soft Clay over Wide Strain Range
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING, cilt.140, sa.2, 2014 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 140 Sayı: 2
- Basım Tarihi: 2014
- Doi Numarası: 10.1061/(asce)gt.1943-5606.0001014
- Dergi Adı: JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Anahtar Kelimeler: Ground motion, Centrifuge models, Clays, Shear strength, Shear modulus, Shear waves, Nonlinear response, Ground motion, Centrifuge models, Clays, Shear strength, Shear modulus, Shear waves, Nonlinear response, AMPLIFICATION, SAND
- Eskişehir Osmangazi Üniversitesi Adresli: Hayır
Özet
Centrifuge models of soft-clay deposits were shaken with suites of earthquake ground motions to study site response over a wide strain range. The models were constructed in an innovative hinged-plate container to effectively reproduce one-dimensional ground-response boundary conditions. Dense sensor arrays facilitate back-calculation of modulus-reduction and damping values that show modest misfits from empirical models. Low-amplitude base motions produced nearly elastic response in which ground motions were amplified through the soil column, and the fundamental site period was approximately 1.0 s. High-intensity base motions produced shear strains higher than 10%, mobilizing shear failure in clay at stresses larger than the undrained monotonic shear strength. The authors attribute these high mobilized stresses to rate effects, which should be considered in strength-parameter selection for nonlinear analysis. This nonlinear response deamplified short-period spectral accelerations and lengthened the site period to 3.0 s. The nonlinearity in spectral amplification is parameterized in a form used for site terms in ground-motion prediction equations to provide empirical constraint unavailable from ground-motion databases.