Autor: N. I. Sheraliev, I. M. Evdokimova, G. M. Kaganov, B. M. Bakhtin, V. I. Bronshtein
Rok vydání: 2001
Předmět:
Zdroj: Hydrotechnical Construction. 35:624-629
ISSN: 0018-8220
DOI: 10.1023/a:1015171506001
Popis: in which λL, λL ,a ndλρ are scale factors respectively related to the geometry, the elastic moduli, and the densities. We simulated the strain state due to static and dynamic loads in the natural gravitational field, but there are great difficulties in satisfying (1) in the field of the Earth’s gravity, since the model requires special equivalent materials with elevated density and low elastic modulus, while having the shear characteristics of natural soils. There are considerable difficulties in selecting such materials even for simulating concrete structures, and the difficulties increase greatly for earth structures. One approach is to use models made of natural soils in an artificial acceleration field, e.g., centrifuge. This greatly complicates the measurements, and also the reproduction of the seismic loads and boundary conditions. We used a mixed simulation: strain pattern from static loads reproduced in a model made from natural soil by means of anchors installed at many points and thin ties attached to them. Forces were applied to the ties equivalent to the weight of the soil acting in an elementary volume, with the anchor in each case at the center of gravity. The hydrostatic water pressure at the upstream face was reproduced by a system of rigid plungers loaded by presses. The static loads could be varied widely up to the failure stage, and the measurements and observations were quite simple and reliable. The seismic (inertial) loads were reproduced on the assumption that the material is linearly elastic in accordance with the Cauchy criterion. In that situation (model made from natural soil), λE = λρ =1 ; if we take the strain scale as λe = 1, then the scales for the accelerations and vibration periods λa and λT are respectively λa =1 /λL and λT = λL. (2)
Databáze: OpenAIRE
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