Bearing Capacity of Soils - Lab Report Example

Bearing Capacity of Soils Abstract The objective of this experiment was to determine the right size for a foundation. It involved conducting tests and analyses of soil to determine the amount of pressure it could handle. The ability of a structure to withstand its own weight or that which it supports determines whether or not the structure will serve its purpose; these structures include buildings, billboards, swimming pools, or even roads. The bases of such structures, therefore, need to be properly designed, keeping in mind the overall soil structure.

If this is not properly done, then the structures are likely to collapse, resulting in massive catastrophes. Sound engineering principles should be employed in the design of such structures in order to avoid potential loses in human life and property (William Powrie 53). There are two major types of foundations; shallow and deep. While shallow foundations are located just below the structures they support, deep foundations extend deep into the earth’s crust. Shallow foundations are thus also called footings or mats, whereas deep foundations can also be called piles, or drilled shafts (Braja M. Das 123). The type of foundation used depends on two factors; the size of the structure to be built, and the category of soil on which the structure is to be built.

Big structures require bigger foundations than smaller structures. On the other hand, organic soils also require bigger foundations compared to cohesive soils.Problem Description This lab was meant to carry out simple soil tests that would eventually be used to decide on the right size of a foundation.Goals The objectives of the lab were as follows:1. Calculate the required size for a building column footing under a given load.2. Determine the effect of varying water contents on the compressive strength of the soil.

Procedure The lab was conducted following the following procedure:1. A test specimen with known percentage of water was selected. The group used soil with 15% water content. This specimen was created by mixing 22.5 grams of water with 127.5 grams of dry clay.2. The next step involved filling the mold with the soil-water mixture in three equal layers using the tamping device. The top of the first and second layers were scored to ensure a good bond with the successive layers.3. Next, the soil was removed from the mold, and its measurements and weight taken to establish the initial length, average diameter, , and the moist mass in grams.4. Next, an unconfined compression test was conducted according to the American Society of Testing and Materials (ASTM) procedure ASTM D2166.

This went as follows:i. The soil sample was placed in the load frame and loaded at a strain rate of between 0.5-2% per minute until it was 15% loaded, i.e. ii. Readings of load and deformation were taken and recorded frequently to allow for the determination of the peak of the  curve for the test.ResultsThe results from the lab experiment were as follows:Discussions1. 2. Graph of stress σ1 versus strain ε1= stress when ε1 = 0.15 (or 15%) strain= 0.5999 lbs/in2 *144 = 86.3856 lbs/ft2Shear strength, su, = 3.

The sample is soft clay because to obtain its unconfined compressive, 15% strain comes before the maximum stress level.4. Allowable bearing (American Society Civ 56)=Size=B=Works CitedAmerican Society Civ. Bearing Capacity of Soils (Technical Engineering and Design Guides As Adapted from the U.S. Army Corps of Engineers). Virginia: American Society of Civil Engineers, 1994. Print.Das, Braja M. Shallow Foundations: Bearing Capacity and Settlement, Second Edition. Boca Raton, FL: CRC Press. 2009. Print.

Powrie, William. Soil Mechanics: Concepts and Applications, Second Edition. Boca Raton, FL: CRC Press. 2004. Print.