Title:
Parametric Study of Slab-On-Grade Problems Due to Initial Warping and Point Loads
Author(s):
Moayyad Al-Nasra and Leon R. L. Wang
Publication:
Structural Journal
Volume:
91
Issue:
2
Appears on pages(s):
198-210
Keywords:
cracking (fracturing); deflection; finite element analysis; loads (forces); models; modulus of elasticity; slabs; Structural Research
DOI:
10.14359/4596
Date:
3/1/1994
Abstract:
The response behavior of rectangular slabs on grade is studied both experimentally and theoretically. A finite element model for slab-on-grade problems is introduced, where the concrete is represented by eight-node brick elements and the expansion joints and the subgrade are represented by boundary-spring elements. To study the warping of the slab on grade, the subgrade boundary elements are taken to be nontension elements to represent the soil-resistant characteristics. Because of the variation of the soil contact area and the cracks in the concrete, a general nonlinear analysis for the response behavior of slabs on grade is developed. Field tests relevant to the warping of floor slabs and edge loadings of a warped slab were conducted. The theoretical finite element results are compared with the experimental measurements. The effects of temperature and moisture gradients, slab thickness, modulus of subgrade reaction, and modulus of elasticity of concrete are studied. An analytical parametric study is performed for edge and corner loadings of a typical floor slab.