Practical Foundation Design with STAAD Foundation Advanced by Tribedi Apurba & Datta Anirban

Author:Tribedi, Apurba & Datta, Anirban [Tribedi, Apurba & Datta, Anirban]
Language: eng
Format: epub
Tags: English
Publisher: Bentley Institute Press
Published: 2018-12-03T00:00:00+00:00

(B) Cover and Soil (Figure 5.7)

Figure 5.7: Data input page for soil and cover parameters.

“Soil Type”: Soil type can be cohesive or cohesionless. It is used to calculate uplift resistance and lateral earth pressure. In Figure 5.7, soil type is selected as “Cohesive.”

“Cohesion/Shear Strength”: Only one input will be active based on the selected soil type. For cohesive soil, SFA needs input for cohesion. For cohesionless soil, the program needs input for undrained shear strength. These input values are used to calculate uplift resistance. In Figure 5.7, cohesion = 6 T/m2 and shear strength input is deactivated (shown as red), as the selected soil type is cohesive.

“Ø Value”: This is the soil friction angle for cohesionless soil (in degree) and used for sliding and overturning check.

“Pedestal Clear Cover”: Clear cover for pedestal design and detailing. In Figure 5.7, pedestal clear cover = 50 mm.

“Bottom Clear Cover”: It is used for bottom, top, and side covers of the footing. In Figure 5.7, footing clear cover = 50 mm.

“Unit Weight of Soil”: Density of soil, which is required to calculate soil weight on top of the foundation. In Figure 5.7, Ys = 20 kN/m3.

“Soil Bearing Capacity”: This is the allowable bearing capacity of soil. Maximum contact pressure during service design must not exceed this value. This input can be either net or gross, which can be set through global settings. However, during internal design calculations, the program always uses gross bearing capacity. So, if a user inputs bearing capacity as net bearing capacity, the program will internally convert it to gross bearing capacity. In Figure 5.7, Soil Bearing Capacity = 200 kN/m2.

“Multiplier of Soil Bearing Capacity for Ultimate Load”: It gives user an option to control the contact pressure even for ultimate design. In other words, contact pressure even for ultimate load cases should not exceed a certain value. This factor is multiplied with the bearing capacity and the program makes sure contact pressure for ultimate load cases remain within that value. Here it is taken as 1.5.

“Type of Depth”: Tells the program whether the soil depth should be considered from the top of the footing or from the bottom of the footing. Here “Fixed Bottom” option is selected.

“Depth of Soil above Footing/Footing Embedment Depth”: Based on the selected “type of depth,” user must input one of the two depths. For “Fixed Top” option, the program considers soil depth as the “depth of soil above footing”. For “Fixed Bottom” option, the program considers soil depth as the “footing embedment depth.” As currently “Fixed Bottom” option is selected, “footing embedment depth” is activated and the input value is 2,000 mm.

“Surcharge”: Surcharge is an additional pressure load acting on top of the footing. It is an optional input and can remain as 0.0. It is shown as 15 kN/m2.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.