Vertical downwards loads (Compression): Pile carrying capacity for vertical downward loads, comes from two things: The frictional resistance over their side face area and Their bottom tip resistance (end bearing resistance) foundations 2 So, piles generate friction force on their side face, plus develop strength at the tip. Tip resistance is also called “end bearing” […]
Deep foundations, also called as pile foundations, are used when there is not sufficiently strong soil at a reasonable depth, and using shallow foundations would cause failure or excessive settlement of the structure, even if that same soil can be a sufficiently strong foundation material for a lighter project. For example, for a bridge, where […]
Design: Shallow foundations are used where the soil has enough bearing capacity and shear strength (in other words strong enough) at a reasonably close depth. The Federal Highway Administration defines shallow foundations as, “a foundation that bears at a depth less than about two times the foundation width”. Under soil mechanics, we have said that […]
In the previous posts we introduced earth materials from a civil engineering point of view and gave an overview of soil mechanics. The entire soil mechanics concepts are studied not for the sake of understanding soils only, but to use them in designing better foundations, slopes and retaining structures. That is when we put the […]
Just like all the subjects we covered for soil mechanics deal with soil properties, rock mechanics deal with the properties of rocks, in order to utilize them as foundations for our structures, and the same principles apply for determination of those properties, with some minor modifications as required. As in soils, the strength of rock […]
Seepage within a soil medium can be shown by flow nets: Groundwater 2a In the figure above we show an seepage flow condition below a dam. The total head anywhere in the water body at the left of the dam is 14m and in the water body at the right side of the dam is […]
Water Head: Since we are explaining subtitle of a subtitle right now, this may seem like a detailed subject in soil mechanics at first… But actually the water head is a very important concept for water resources engineering, one of the five main branches of civil engineering, which we mentioned before briefly and will introduce […]
Almost everywhere on earth, we can find water below the land surface, which is called groundwater. For example, approximately 50% of the drinking water in the US comes from groundwater per American Institute of Geosciences. We also use groundwater in agriculture, and therefore it is a very essential resource. Although it obvious benefits for our […]
Geotechnical reports show the site soil, rock and groundwater conditions to be used for designing foundations of all types of structures. They are prepared for each project, based on data obtained from subsurface investigation and soil testing and measurement, as discussed in the preceeding two subsections above plus other sources. It is very important to […]
Sieve Analysis: The most fundamental soil test of all, is the sieve analysis. It is used to determine what type of soil are we dealing with, in the first place. It is like asking a person his or her name (is the soil mainly gravel? sand? silt? clay? and in what proportions?). Through this test, […]