Methods of measuring load-bearing capacity of soil

CBR test :

CBR "CBR" means the carrying capacity and a high standard of road engineering in California, compared with a mixture of clay soil or load-bearing capacity of the soil binder, explains. 

A bowl of CBR CBR (diameter 150 mm), which is located in the pressure test is a punch in the continuous feed speed in the sample. California, compared with the corresponding pressure to penetrate the soil to a standard depth of 2.5 mm and 5, and in order to achieve the required pressure is determined by the punch. CBR is then calculated as a percentage of the value. CBR values ​​can also be used when evaluating the resistance of the snow.

Plate load test :

This is painting a pregnancy test soil (underground), and the flexibility of pressure and open site to determine load-bearing capacity outside pursuant DIN 18134. to this, the pressure of the appearance of lines, deformation Carrying capacity of the unit EV2 (see MN / square meter) in the form. The word has the ability to load-bearing soil in the bottom of the earth (or will be within the tolerance of the formation), which is the formation of the maximum pressure under which it is understood. 

Is loaded plate diameter in several stages, depending on the size of the soil particles and the soil is placed in a test panel standard. As mentioned before this is repeated until either the formation or the pressure of the fixed plate.

Steps for the Selection of the Type of Foundation

In choosing the type of foundation, the design engineer must perform five successive steps.

1. Obtain the required information concerning the nature of the superstructure and the loads to be transmitted to the foundation.

2. Obtain the subsurface soil conditions.

3. Explore the possibility of constructing any one of the types of foundation under the
existing conditions by taking into account
   
       (i) the bearing capacity of the soil to carry the required load, and
       (ii) the adverse effects on the structure due to differential settlements.Eliminate in this way, the unsuitable types.

4. Once one or two types of foundation are selected on the basis of preliminary studies, make more detailed studies. These studies may require more accurate determination of loads, subsurface conditions and footing sizes. It may also be necessary to make more refined estimates of settlement in order to predict the behavior of the structure.

5. Estimate the cost of each of the promising types of foundation, and choose the type that represents the most acceptable compromise between performance and cost.