Lateral Earth Pressure

Lateral Earth Pressure

In designing retaining structures, the most critical thing to know is how much horizontal (lateral) pressure the retained soil will exert on the retaining structure, such as a retaining wall. In previous post, we learned how to calculate the vertical stresses soils. Here, we must somehow derive horizontal pressure from it. To do this, we […]

Shear Strength of Soil

We introduced shear stress before in this book. If you are not an engineer, and forgot what shear stress means, first please go back to section Structural Basics > Forces and look at again, what it means “shear”. Now, Imagine the following different situations: Think of water running down a sloped street. It can flow, […]

Soil Strength

This is the heart of soil mechanics, where we calculate the stresses in soil, and how it will settle based on these stresses, in other words, strength of soil. It mainly contains the following topics, which we will introduce each below.   Total stress, effective stress (soil skeleton stress), pore water pressure Shear Strength of […]

Soil Classification

From strongest to weakest, soils can be listed in order as: Rock > Gravel > Sand > Silt > Clay > Organic Soils The word “strong” here, means shear stress supporting ability, which in turn means bearing capacity of the soil, which basically means, load carrying capacity of the soil. These will be talked about […]

Soil phase relationships

Let’s start with the basics, phase relationships, which is the first thing to learn in soil mechanics… Any given soil volume contains solid particles, water, and, if it is not fully saturated, air too. Phase relationships define the volume and weight relations in soil for solids, water, and air. These relationships are fundamental to know […]

Soil Mechanics

So far in this post series, we introduced the most basics of structural related concepts, (most of which of which we will also use in this section too) and now we can move on to geotechnical branch of civil engineering. As we mentioned before, geotechnical branch is mainly separated into two as soil mechanics and […]

Stress vs Strain, Elasticity Modulus

Stress vs Strain, Elasticity Modulus

After discussing stress and strength, the next important item to know is the relation of stress versus deformation. Imagine a material which is somehow perfectly rigid. In other words, it never deforms, no matter how large, even infinite, load you apply on it. In nature no such material exists. Every material, no matter how strong, […]

Mohr’s Circle

Mohr’s Circle

In many cases, when performing structural or geotechnical calculations, it is important to know the possible effects of stresses that act on materials not from just one direction, as we saw above, but from multiple directions, which happens quite a lot. The effect of stresses acting from multiple directions will cause the materials to fail […]