Louis Flores's Communities Activities

STAAD Foundation Advanced - Specified Area for Loss of Contact

Louis Flores — Mon, 30 May 2022 05:58:26 GMT

Hi,

In the attached SFA file and image, I specified that there should be 100% contact for service load combinations (see footing no. 1). However, when I check the area in uplift for these load combinations, the footing still experiences loss of contact. Can somebody please explain why is this the case?

communities.bentley.com/.../0434._5B00_CE-196_5D00_-_2D00_-Isolated.sfa

STAAD Foundation Advanced Interpretation of Error Message

Louis Flores — Wed, 01 Jun 2022 09:37:39 GMT

Hi,

I received an error like the one in the image below from SFA. Can somebody explain it to me? Why is it that the software is unable to redistribute the pressures? Is it because that all the corners have negative pressures?

STAAD Foundation Negative Pressures

Louis Flores — Thu, 26 May 2022 07:17:44 GMT

Hi,

In the design of footings against shear and moments, we determine the volume of pressure underneath the critical section. How does SFA compute this when there is a negative pressure? Does it redistribute the pressure so all corners have positive pressures or does it simply ignore the negative pressures?

STAAD Foundation Eccentricity Beyond Kern

Louis Flores — Thu, 26 May 2022 10:47:04 GMT

Hi,

I have set my isolated footing design to remain in full contact with the soil. However, when I check the eccentricity of the factored loads, it is beyond the kern which is 1/6 of the footing dimension.

1) Why does SFA give out such design when this kind of footing design is unacceptable?

2) Given that the eccentricity is beyond the kern, does this mean that my footing is experiencing loss of contact?

communities.bentley.com/.../8030.Isolated-Footing-_2D00_-Axial.sfa

STAAD Foundation One-Way Shear Discrepancy

Louis Flores — Sun, 29 May 2022 02:41:21 GMT

Hi,

In the SFA file below, please look at "Interior" job. When I verified the one-way shear capacity, I computed it to be Vc=348.29kN but the software calculated it to be Vc=335.04kN. My calculations are found below:

Vc = 0.17 * (1) * (2000mm) * (209.1mm) * sqrt(24MPa) * (1/1000) = 348.29kN

Please help me determine why there's a discrepancy.

communities.bentley.com/.../_5B00_CE-196_5D00_-_2D00_-Isolated-Finalized.sfa

Design of Foundation Dowels

Louis Flores — Sat, 28 May 2022 16:07:18 GMT

Hi,

Is there anyone who is experienced in designing footing dowels? I just have a question: if the bearing strength of the column and footing concrete exceeds the maximum compressive compressive force, do we still need to provide sufficient development length for the dowels?

STAAD Foundation Shear Computation

Louis Flores — Wed, 25 May 2022 13:28:01 GMT

Hi,

How does SFA compute for the one-way shear? I tried to manually compute it but I obtained 5.1kN while the software computed 4.8kN.

communities.bentley.com/.../8015.Isolated-Footing-_2D00_-Axial.sfa

STAAD Foundation Uplift Pressure

Louis Flores — Thu, 26 May 2022 04:25:21 GMT

Hi,

In my SFA, please refer to "Preliminary Design - Isolated" job. I have set that the minimum contact area for both service and ultimate load cases should be 100%. However, for Isolated Footing 1, I noticed that there is still negative pressures underneath the footing (see photo). Why is it that there are negative pressures but the table (see photo) shows that there is no loss of contact?

communities.bentley.com/.../1641._5B00_CE-196_5D00_-_2D00_-Isolated.sfa

STAAD Foundation Stability Check

Louis Flores — Thu, 26 May 2022 05:59:18 GMT

Hi,

Why is it that the stability check of footings in SFA is only performed for service load combinations?

STAAD Foundation - Steel Density

Louis Flores — Mon, 23 May 2022 07:36:02 GMT

Hi,

How does SFA determine the mass of reinforcement steel? Where can I find the steel density value/s that SFA uses?

STAAD Foundation Effective Depth Calculations

Louis Flores — Wed, 25 May 2022 05:48:28 GMT

Hi,

I am designing an isolated footing in SFA. I just want to clarify some things with regard to the calculations used by the software:

1) In the shear calculation, the calculated effective depth does not match hand calculation. Hand calculation shows 0.165m but SFA solved it to be 0.1655m (Example from Isolated Footing 1). Through back calculation, I found that SFA uses 9.5mm for the reinforcement steel diameter instead of 10mm. Why is it that STAAD uses 9.5mm diameter when I have selected a 10mm steel diameter size from the design menu? Why wasn't this updated by the software developers?

communities.bentley.com/.../Inquiry-on-Calculation.sfa

STAAD Foundation Incorrect Spacing

Louis Flores — Mon, 23 May 2022 12:47:05 GMT

Hi,

I am designing isolated footings. However, the flexure rebars' spacing are not consistent with the calculation sheet and the drawing. How do I resolve this? What spacing value should I follow?

communities.bentley.com/.../_5B00_CE-196_5D00_-_2D00_-Isolated.sfa

STAAD Foundation - Transfer Graph in Excel

Louis Flores — Sun, 22 May 2022 13:50:30 GMT

Hi,

Is there a way to transfer the shear and moment diagrams to Excel?

SFA User Defined Load Combinations

Louis Flores — Sat, 21 May 2022 05:06:25 GMT

Hi,

I want to define my own set of load combinations. How do I add more load combinations?

Cracking Condition of Footings

Louis Flores — Fri, 20 May 2022 18:09:31 GMT

Hi,

In SFA, the software checks the maximum spacing for a cracking condition. Do we always have to follow this maximum spacing for cracking condition? If not, what are the justifications for not following this ACI provision?