Westergaard's Equation - Which Is Correct Equation For Line Load?

Diode load line. The curve shows the diode response (I vs VD) while the straight line shows the behaviour of the linear part of the circuit: I=(VDD-VD)/R. The point of intersection gives the actual current and voltage.

What are the assumptions of Boussinesq equation?

Boussinesq's theory formula is based on following assumptions. The soil mass is semi-infinite, homogeneous and isotropic. The soil has a linear stress-strain relationship, The soil is weightless.

What is oberbeck Boussinesq approximation?

The Oberbeck-Boussinesq approximation is the most widely employed theoretical scheme for the study of natural or mixed convection flows. However, the misunderstanding of this approximated framework is a possibility that may cause the emergence of paradoxes or, at least, incorrect conclusions.

What is the eddy viscosity hypothesis?

The eddy viscosity hypothesis is that this dissipativity can be modelled by a viscosity term with particular flow features captured by a turbulent viscosity coeffi- cient. These assumptions are the foundation most turbulence models used in practical computations.

What is direct stress formula?

Direct stress (σd) is produced when applied load acts on a body. Mathematically, σd= Axial applied compressive or tensile load/Area of cross section = P / A.

What is the formula for stress ratio?

The stress ratio R is usually defined as minimum stress value divided by maximum stress value, which leads to values between -∞ and +1.

What are the assumptions in terzaghi bearing capacity theory?

1. The soil is homogeneous and isotropic and its shear strength is represented by Coulomb's equation. 2. The strip footing has a rough base, and the problem is essentially two-dimensional.

What is difference between bearing capacity and allowable bearing capacity?

The ultimate bearing capacity is the maximum possible load that can be supported without failure (e.g., by overturning of a building). Allowable bearing capacity is a load not to be exceeded without causing settlements too great for a given structural or operational application.

What are the factors affecting compaction?

Factors affecting compaction Nature and type of soil, i.e. sand or clay, grading, plasticity. Water content at the time of compaction. Site conditions, e.g. weather, type of site, layer thickness. Compactive effort: type of plant (weight, vibration, number of passes)

What is difference between Boussinesq theory and Westergaard's theory?

Boussinesq's theory considers that the medium of soil is isotropic while Westergaard's theory considers that the medium of soil is anisotropic.

Why Terzaghi is the father of soil mechanics?

Abstract. If civil engineering were a game, Karl Terzaghi had a right to lay down the rules—he had invented and established much of the groundwork. Terzhaghi (1883-1963) is one of the leading civil engineers of the 20th century and is widely known as the father of soil mechanics.

What are the three stages of consolidation?

The consolidation of soil is divided into three stages including initial consolidation, primary consolidation, and secondary consolidation. The consolidation of soil is time-dependent and its analysis is usually based on Terzaghi's theory.

What is normal stress formula?

The dashed lines are the projections of the principal stress axes onto a deviatoric plane (i.e. a plane normal to the hydrostatic axis σ1 = σ2 = σ3, also called the π-plane) passing through the point (σ1,σ2,σ3).

What are the two basic types of compaction?

Almost all types of building sites and construction projects utilize mechanical compaction techniques. These different types of effort are found in the two principle types of compaction force: static and vibratory.

What is terzaghi theory?

Terzaghi's Principle states that when stress is applied to a porous material, it is opposed by the fluid pressure filling the pores in the material.

What is 2 1 stress distribution method?

Vertical Ratio 2:1 Method For a non-rectangular footing, the stress is calculated by computing the area of the load at the surface. With increasing depth, the area over which the load is applied increases at a 2:1 ratio and the magnitude of the loading stress decreases correspondingly.

What is Boussinesq equation in soil mechanics?

Boussinesq's equation for vertical stress σ z = Q Z 2 × 3 2 π × [ 1 1 + ( r Z ) 2 ] 5 2. Where, σZ = vertical stress in kN/m2. Q = concentrated load in kN. Z = point below the ground level where stress has to be calculated.

What is sand boiling condition?

Sand boils or sand volcanoes occur when water under pressure wells up through a bed of sand. The water looks like it is boiling up from the bed of sand, hence the name.

What is Terzaghi bearing capacity?

Terzaghi's Bearing Capacity Theory This theory states that a foundation is shallow if its depth is less than or equal to its width. Later investigations, however, have suggested that foundations with a depth, measured from the ground surface, equal to 3 to 4 times their width may be defined as shallow foundations.

What are the assumptions involved in Boussinesq's and Westergaard's theory?

The Boussinesq theory assumes that the soil mass is isotropic. Actual sedimentary soils are generally anisotropic. Thin layers of sand are usually embedded in a homogeneous clay deposit. Westergaard's theory assumes that thin sheets of rigid material are sandwiched in a homogeneous soil mass.