How does liquid limit affect the shear strength of soil?

Undrained shear strength of a soil at the liquid limit can be considered to be around 1.7 kN/m2. The undrained shear strength-water content relationship has been found to be log-linear for a wide range of water contents beginning from lower than the plastic limit to higher than the liquid limit.

Which two factors are responsible for shear strength of soil?

The shear strength of soil depends on the effective stress, the drainage conditions, the density of the particles, the rate of strain, and the direction of the strain.

How is shear strength of soil determined?

Direct shear test is a simple and commonly used test performed in a shear box to determine the shear parameters of soils. A graph is plotted between the normal stress and the shear stress and the y-intercept and the slope of the failure envelope so obtained are taken as the shear parameters c and ɸ, respectively.

What is the shear strength of a soil?

Shear strength of a soil is indicative of its resistance to erosion. Specifically, it is defined as the resistance to deformation by the action of tangential (shear) stress. Soil shear strength is made up of cohesion between particles and resistance of particles sliding over each other due to friction or interlocking.

Why is the liquid limit important?

Why to Know Liquid Limit of Soil? Value of liquid limit is used to classify fine grained soil. It gives us information regarding the state of consistency of soil on site. Liquid limit value of soil is also used to calculate activity of clays and toughness index of soil.

Can the liquid limit of a soil be greater than 100?

The consistency of fine-grained soil for different moisture content is described by Atterberg’s limits. Liquid limit, plastic limit, shrinkage limit etc are some of the Atterberg’s limits. Therefore, the Atterberg’s limits can be greater than 100.

Why is shear strength of soil important?

Shear strength is a very important property of soils. The concept is used by geotechnical engineers in estimating the bearing capacity of foundations and in assessing the stability of retaining walls, slopes, and embankments and the design and construction of highway and airfield pavements.

What is shear strength and which factors affect shear strength?

The shear strength of cohesionless materials is essentially controlled by five factors: (a) mineralogical composition, (b) size and gradation of the individual particles, (c) shape of the individual particles, (d) void ratio or dry density, and (e) confining pressure.

Why is soil shear strength needed?

Shear strength is defined as the maximum shear stress that the soil may sustain without experiencing failure. Shear strength is a critical parameter in geotechnical projects. It is needed to derive the bearing capacity, design retaining walls, evaluate the stability of slopes and embankments, etc.

Why is shear strength of a soil important?

Why is it important to know the liquid limit of soil?

Value of liquid limit is used to classify fine grained soil. It gives us information regarding the state of consistency of soil on site. Liquid limit of soil can be used to predict the consolidation properties of soil while calculating allowable bearing capacity & settlement of foundation.

What is meant by liquid limit of soil?

At the Liquid Limit, soils have very small shear strength which may be overcome by the application of a little force, and cohesion is practically zero. The liquid limit serves mainly to distinguish soils with respect to the amount of moisture necessary to make them to slide.

What determines the shear strength of a soil?

Thus, the shear strength of a soil is mainly governed by the effective stress. Besides the effective stress between soil grains, the pore water contained in the void spaces of the soil also exerts pressure which is known as pore pressure, u.

How to perform liquid limit test of soil using cone penetrometer?

2. Liquid Limit Test of Soil Using Cone Penetrometer Apparatus Prepare a soil paste by mixing soil sample passing 425 micron sieve & water. Transfer this paste to the cup of cone penetrometer apparatus. Set the penetrometer in such a way that the cone just touches the surface of the soil paste.

What is shear strength of pervious and impervious soils?

Shear Strength of Pervious and Impervious Soils. The pore water affects the physical interaction of soil particles. Soils with inactive surfaces do not absorb water, but clay particles, formed of silicates which are frequently, charged electrically, absorb water readily and exhibit plastic, shrinkage, and swelling characteristics.