V Международная студенческая научная конференция Студенческий научный форум - 2013

In paper the conditions for the modeling of facilities' ground bases are summarized. Design for the ultimate strain ε ≤ ε_пр , (ε – strain). It is shown in this study that single design strain value for a roadway section does not yield an effective design regarding target reliability.

Your home's foundation is one of the most important structural components of the house. When your home is set up on a solid foundation, your house has the necessary support for maintaining integrity and will stand for many decades. If the foundation to your house is not properly set, you could encounter any number of problems. Design scheme (fig.1):

Figure 1.

u(x,y,z)=0; v(x,y,z)=0, horizontal displacements.

Stress components:

.

,

where, and are the subgrade shear forces per unit length acting on the plane orthogonal to and direction respectively and is called as subgrade shear modulus. So, the net upward vertical pressure () is:

, are the bending moments per unit length due to load, parallel to and axis respectively, and is the respective twisting moment in the plane.

Where, flexural rigidity, .

Therefore, the equilibrium equation for plate resting on Pasternak foundation become:

The Winkler foundation is a special case of Pasternak foundation (ie when, ).

A combination method of the Newton iteration and two-level finite element algorithm is applied for solving numerically the steady  equations under the strong uniqueness condition. This algorithm is motivated by applying the m Newton iterations for solving the problem on a coarse grid and computing the  problem on a fine grid. Then, the uniform stability and convergence with respect to ν of the two-level Newton iterative solution are analyzed for the large m and small H and h << H [3].  

Concrete pavement is generally modeled as thin plate resting on elastic foundation. The load stress is tensile at bottom. The solutions are different for different types of foundations, such as Winkler, Pasternak,  etc.

The temperature stress develops in concrete pavement due to the change of temperature and the existence of temperature gradient across its depth. Most of the studies show that this temperature distribution is non-linear.

Primarily self-weight provides the restraint against bending  of concrete pavement. The parametric study is carried out to observe the location of the plate lift-off and the variation of the deflection profiles for comparing the variation pattern reported in the literature based on an approximate solution technique. It is found that the radial distance of the point of lift-off of the plate decreases with increase in the values of both the shear modulus and the modulus of subgrade reaction of the foundation soil; the reduction being more for their lower values. It is also observed that the variation in deflection of the plate at any radial distance due to change in soil subgrade conditions is significant for lower values of modulus of subgrade reaction.

1. Slab resting on Winkler foundatio/ http://nptel.iitm.ac.in /courses/105104098.

2. Shukla, Sanjay Kumar and  ot. /Analysis of circular elastic plate resting on Pasternak foundation by strain energy approach. Geotechnical and Geological Engineering, 29 (4), 2011. P. 613-618.

3. Numerical Methods for Partial Differential Equations Volume 28 , Issue 5, pages 1620-1642 , September 2012.

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