Seismic and Wind 1 of 3

Summary

The script discusses a building's structural analysis in San Guillermo Isabella, referencing the NCSP 2015 for seismic and wind load calculations. It covers determining the nearest fault line, seismic source type, and near-source factors for earthquake resistance. For wind load, it details calculating risk category, basic wind speed, and topographic factors for a low-rise building. The process includes interpolating wind pressures for different zones and truss dimensions, ultimately computing design wind pressures and loads for structural components.

Takeaways

• 🏢 The building is located in San Guillermo Isabella and is being assessed according to the NSCP 2015 guidelines.
• 📏 The nearest fault line is measured to be 12 kilometers away from the building using a specific scale.
• 🌟 The seismic source type is classified as Type A, and the magnitude range is between 7 to 8.4.
• 🔍 The Near Source Factor 'Na' is determined to be 1, as the distance is greater than 10 kilometers.
• 🏗️ For wind load assessment, the building is categorized as a low-rise structure less than 18 meters in height.
• 📚 The risk category is determined as 'C' and the basic wind speed 'V' is identified as 290 kph from a map.
• 📈 Topographic and importance factors are assumed to be 1 for general flat terrain and standard occupancy category 4.
• 📐 The mean roof height 'h' is 10.7 meters, which is used to determine the wind load parameters.
• 🌪️ The net design wind pressure is calculated by interpolating values between wind speeds of 250 and 300 kph.
• 🔢 The effective area for truss and柏林(possibly a typo or misheard word, consider checking the transcript) is calculated using specific formulas.
• ⚙️ The wind forces for different zones are computed, taking into account the truss spacing and adjustment factors.

Q & A

What is the building location mentioned in the transcript?

The building is located in San Guillermo, Isabella.

What is the purpose of Figure 208-2D from NSCP 2015?

Figure 208-2D from NSCP 2015 is used to determine the Near Source Factor and the Seismic Source Type based on the building's location and the distance to the nearest fault line.

How is the Near Source Factor (N) determined in the transcript?

The Near Source Factor (N) is determined based on the distance from the building to the nearest fault line, which is measured to be 12 kilometers, indicating a value of N as 1 since the distance is greater than 10 kilometers.

What seismic source type is identified for the building?

The seismic source type identified for the building is Type A, based on the information provided in the transcript.

What is the process for determining the wind load parameters in the transcript?

The process involves determining the risk category, basic wind speed, topographic factor, importance factor, mean roof height, and then using these parameters to calculate the net design wind pressure.

What is the basic wind speed (V) for the building location according to the transcript?

The basic wind speed (V) for the building location is 290 kph, as determined from the map in Figure 207-A.5-1.

What is the topographic factor (Kjt) assumed for the building?

The topographic factor (Kjt) is assumed to be equal to 1, which is for generally flat terrain.

How is the mean roof height (h) used in the calculation of wind load parameters?

The mean roof height (h) is used to determine the wind load parameters by interpolating between the values provided in Figure 207-8.5-1 based on the roof height and exposure category.

What is the effective wind area for the truss and the Berlin in the transcript?

The effective wind area for the truss is the minimum of 2.25 * 13.1 square meters or 9.5 square meters, while for the Berlin, it is calculated as the maximum of (2.25 / 3) * 2.25 * 0.8 square meters or 1.8 square meters.

How are the net design wind pressures (Pn) calculated for different zones in the transcript?

The net design wind pressures (Pn) are calculated by interpolating between the wind pressures for areas of 1 square meter and 2 square meters at different wind speeds (250 and 300 kph), and then adjusting for the specific wind speed of 290 kph.

What is the final step in calculating the wind forces for the building components?

The final step is to compute the loads for the components by multiplying the adjustment factor, the topographic factor, the net design wind pressure, and the component spacing.

Outlines

00:00

🏢 Building Location and Seismic Considerations

The script discusses the building's location in San Guillermo Isabella and references figure 208-2d from NSCP 2015. It addresses the measurement of the nearest fault line, which is 12 kilometers away, and the seismic source type 'A' with a magnitude range of 7 to 8.4. The near source factor 'a' is determined to be 1 due to the distance being greater than 10 kilometers. The near source factor 'b' is calculated through interpolation since the distance falls between 10 and 15 kilometers, resulting in a value of 1.12 for 'b'. The script also mentions wind load considerations for low-rise buildings, using simplified procedures from page 2-138 of NSCP 2015, and outlines steps to determine risk category, basic wind speed, and wind load parameters.

05:01

📐 Calculating Wind Load Parameters and Building Dimensions

This paragraph delves into the specifics of calculating wind load parameters, starting with the topographic factor 'kjt' assumed to be 1 for flat terrain. It then discusses the importer's factor for standard occupancy category four and the mean roof height 'h' as an input point. The script provides a method to interpolate the gust effect adjustment factor based on roof height and exposure category. It also identifies the building's dimensions, including the fronting wind dimension 'b', bottom chord length 'w', truss spacing 'l', and height of truss 'h'. The effective area for the truss and Berlin is computed, considering the truss spacing and Berlin spacing, leading to the calculation of the net design wind pressure.

10:04

🌪️ Determining Net Design Wind Pressure and Interpolation Methods

The script explains the process of determining the net design wind pressure by interpolating values between basic wind speeds of 250 and 300 km/h. It provides detailed steps for calculating windward and leeward pressures for different effective wind areas, considering the building's roof angle which ranges from 7 to 27 degrees. The script specifies the interpolation procedures for zones one, two, and three, and how to adjust these values for different wind speeds and effective wind areas. It also outlines the computation of wind forces for the building's components, such as trusses and Berlin, using the determined wind pressures and adjustment factors.

15:05

🔢 Final Computations for Wind Loads on Building Components

The final paragraph focuses on the computation of wind loads for the building's components, specifically the furlins, using the previously determined values for zones one, two, and three. It provides the equations and calculations for the wind forces, including the use of the adjustment factor, topographic factor, and net pressure. The script also discusses the computation of the area for the truss, taking into account different wind speeds and the truss angle. The paragraph concludes with the tabulation of computed loads for the furlins in each zone, highlighting the importance of accurate interpolation and calculation for structural design.

Keywords

💡San Guillermo Isabella

San Guillermo Isabella appears to be the name of the location where the building in question is situated. This is crucial for understanding the context of the video, as the geographical location can significantly influence the design and structural requirements of a building, especially in terms of seismic and wind loads.

💡Etopoion

Etopoion is a term that seems to refer to the topographical or geographical characteristics of the building's location. In the context of the video, it is used to measure distances, such as the proximity to a fault line, which is essential for assessing seismic risks.

💡Fault Line

A fault line is a fracture in the Earth's crust where seismic activity can occur. In the video, the distance to the nearest fault line is measured to determine the seismic risk for the building, which is a critical factor in structural engineering and safety planning.

💡Seismic Source Type

Seismic source type categorizes the nature of the seismic activity that could affect a building. In the script, it is mentioned as 'Type A,' which likely refers to a specific classification system used to assess the potential impact of earthquakes on structures.

💡Magnitude

Magnitude refers to the size or strength of an earthquake, measured on a scale. In the video, the magnitude range of 7 to 8.4 is mentioned, indicating the potential scale of seismic events that the building must be designed to withstand.

💡Near Source Factor

The near source factor is a parameter used in seismic analysis to account for the proximity of the seismic source to the structure. It is used to adjust the seismic forces applied to the building in the design process, as mentioned in the script when discussing the building's location relative to the fault line.

💡Wind Load

Wind load is the force exerted on a structure by wind. The video discusses calculating wind loads for a building, which is essential for ensuring the structural integrity and safety of the building against high winds, especially for low-rise buildings as mentioned in the script.

💡Risk Category

Risk category is a classification used to determine the level of risk a building poses in terms of occupancy and use. In the video, it is used to categorize the building and apply appropriate design standards from the NSCP 2015, which is crucial for ensuring safety and compliance.

💡Basic Wind Speed

Basic wind speed is a measure of the average wind speed at a location, used in engineering to design structures to withstand wind forces. In the video, it is determined using a map and is a key parameter in calculating wind loads for the building.

💡Topographic Factor

The topographic factor is a multiplier used in wind load calculations to account for the influence of the local terrain on wind speed and direction. In the video, it is assumed to be 1 for generally flat terrain, simplifying the wind load calculations.

💡Effective Wind Area

Effective wind area is the surface area of a structure that is exposed to wind and contributes to the wind load. In the video, it is calculated for both the truss and the Berlin, which are structural components of the building, and is essential for determining the wind forces acting on the building.

Highlights

Building located in San Guillermo Isabella, with specific focus on Figure 208-2D from NSC 2015.

Identification of the nearest fault line at a perpendicular distance of 12 kilometers using a music scale.

Determination of seismic source type A for magnitudes 7 to 8.4 from Table 2-8-4.

Calculation of the near source factor and A, with a distance greater than 10 kilometers indicating a value of 1.

Interpolation method used for near source factor B, with the distance between 10 and 15 kilometers.

Wind load considerations for low-rise buildings using simplified procedure from page 2-138 of NSC 2015.

Risk category determination for occupancy category I-4 as per Table 103-1 and Table 207-3.

Basic wind speed V determined using a map, with a value of 290 kph for the building location.

Topographic factor Kzt assumed to be 1 for generally flat terrain.

Importance factor I set to 1 for standard occupancy category 4.

Mean roof height H calculated as 10.7 meters, with specific attention to input points.

Interpolation of wind load parameters for roof height and exposure category C.

Identification of building dimensions for wind load calculations, including fronting wind dimension B.

Effective area computation for truss and Berlin based on minimum and maximum equations.

Determination of net design wind pressure with interpolation for wind speed and effective area.

Interpolation procedures for different wind speeds and zones for accurate wind load calculations.

Computation of wind forces for truss and Berlin, adjusting for specific factors and spacing.

Tabulation of wind loads for different zones, considering the unique characteristics of each.

Transcripts

our building is located in

san guillermo isabella so

let's go to figure 208-2d from

nscp 2015. so located in

san guillermo isabella let's say

etopoion

building location so measuring

perpendicularly

using this scale the nearest

fault line is at the po in music scale

let's say that is 12 kilometers second

from

nothing distance and then again for

nothing seismic source type

is type a so from

table 2 8-4

magnitude 7 to 8.4

magnitude next

we will determine now the near source

factor

and a so the closest distance is

12 kilometers or that is greater than 10

kilometers

so nothing

so i think n a is

one next is

near source factor and b so you'll

notice that

the distance is between 10 and 15 so we

will do ratio

and proportion or interpolation so from

one point two to one lumalum is now one

point twelve and i think

np

next is wind load i'm not in building

for a

less than 18 meters so we will use

low rise buildings component and

cladding

simplified procedure that is on page

2-138

of nscp 2015

so step one determine risk category

c table 103-1

so also you see

table 207-3 and i think occupancy

category i

4 and then step 2 determine the basic

wind speed v

now using this map figure 207

a dot 5-1 a and location phonon building

i nasa 290 kphd

and then step two uh

applicability race category c figure

207 a that five one a

comma b or c i'm adding

category i c at the top

and then step three we will determine

wind load parameters

we start with topographic factor

kjt we will assume

topographic factor kjt equal to

1 that is for generally

flat terrain

next is the importers factor i

uh

one that is for standard

occupancy with category

four at the bottom

and then our mean roof height h

is 10.7 min roof height

means the distance from the

uh middle of the truss height

down to the ground

so you'll notice that this is marked

red meaning input point

and then go from picking tonight

adjustment factor uh

based from this figure 2078.5-1

you'll notice that our main roof height

10.7 is between

10.5 and 12 and then

our exposure category is

c so we will be using this column

so fanta pattern i can see 10.5

and 12 liters of c so i'll interpolate

so from 1.45 to 1.49 and using

10.7 as your x-axis

and then a total of 1.45 you're going to

y axis

factor is 1.4

so that is by interpolation

nscp 2015 is based from ss7-10

so what are components and cladding

uncladding employee roofing sheets

and then component and poyon berlin's

head trusses so cladding and

aggregate

for our wind loads we will consider

only

and then finally we have zone three and

foreign

next we now

um identify the dimensions of our

building so uh building with

fronting wind so that is your b

so that is 13.5 meters so that

is the dimension fronting the wind

and then the bottom chord length or that

is w

that is 13.1 at the point w

and then truss spacing l that is two

point twenty five so

considering inputs

and then our berlin spacing is point

eight

and finally the height of thrust is two

point

two and then you will notice that the

mean group height h is from the

ground up to the mid height of

your truss now let's

compute the area effective of the truss

that is the minimum of two equations so

that is

lw or 9.5

square meters so we will compute 2.25

and 13.1 you will multiply that

um so that is

2.25 times 13.1

is 29.4675 so i'm gonna committing

nothing

i 9.5 square meters

and then for effective area for

berlin the computation is the maximum of

these two equations multiplied by

l so l all over 3

is 2.25 divided by 3 and then

s so

2.25 divided by 3

multiply this by

l 2.25

so 1.6875

and then we multiply s

0.8 and

our length 2.25 so that

is one point eight

square meters so yeah i'm gonna begin

again 1.8

square meters

okay next we now determine the

net design wind pressure

peanut so i'm

adding basic wind speed v

i 290 notice that 290

is between 250 and

300. again but the interpolation of

diode

so remember that we are

using zones considering zones one

two and three only so remember between

zone one

zone two so sides and zone three saw

corners so

and then anger nothing i

roof angle is

from seven to 27

degrees okay so entering zones my zone

one

then my zone two on my zone three

ethanol

effective wind period take note that the

effective wind

area is up to 9.5

square meters only

okay so marathon

so notice that 1.8 is between

one and two

and then um wind speed i

nasa 250 chaka

three hundred so i don't know nothing

okay so let's continue

so we will now do the interpolation

procedures so

so we have zone 1 250

okay so young area one

in one point one point nine yanyon

windward and

reward pressure

one point two it's about negative 1.9

this is spin ward and reward pressure so

mobile passenger

windward is 1.2

positive pressurian

itunes and then for

reward negative 1.9 meaning

it is suction next we now go to

two square meters like area we have

one point zero nine and negative

one point eighty five yen

okay so two one point zero nine and

negative

one point eight five so remember now you

are enough in i

1.8 so you do uh

interpolation again so you get 1.11 and

negative 1.56

and that's for 250

and now we go to 300 wind speed

so here you want we have

one point seventy twenty two cell

windward and negative

two point seven four here you want

now one square meters

next for two square meters

saw 300 in the wind speed you have

sevens of 1.57 and negative 2.66

okay next for 1.8

you do interpolation okay so you have

one point six

and negative two point sixty and one

point six

nine that is between one point seven and

one point seven

two and negative two point six eight is

between negative 2.66

and negative 2.74

now let's go to our output

wind speed now 290 so remember

290 is between 250 and 300.

next we will interpolate uh

this so windward area one for

290. this is taken from

one point two and one point seventy two

next atom among one point four seven

four

nangali nyan ditosa one point

zero nine chapati 1.57 so

this is windward area 2 then this is

also windward

area 2. so that's how you get 1.474

next d ties are negative two point five

seven two

this is interpolated between

negative one point nine square negative

two point seven four and then at all

negative two point four nine eight

that is interpolated between

uh one point eighty five negative

chapter negative

two point six six

and then from this

values uh from one point four seven

four to one point sixty six mug

interpolate tile

uh from one to two and i'm letting

x i one point eight makoku among ion c

one point five and then the interpolate

minimum

uh between negative two point four

nine eight and negative two point five

seven two

the patmos is one point eight ten c

negative two point fifty one so

one point five negative two point fifty

one

but this is only four zone 1

of wind speed 290. you do the same

procedure for

zone 2 okay for zone 2

this is zone 2 and you get 1.5 and

negative

4.19 you do the same procedure again for

zone 3 and you get 1.5 negative

6.27

next

um i think berlin is spacing i i know

0.8 meters and then our

adjustment factor is 1.455 and

our case 80 is one

after computing

all the wind forces we now tabulate them

here

so for zone one we have 1.5 and negative

two point fifty one okay

and then for zone two we have one point

five

and negative four point nine and for

zone three 3

1.5 and negative 6.27

so now we compute the loads for our

furlings so for zone 1 we have 1.749

uh that equation is

adjustment factor times kjt times

p net nine times s

okay so let's do that also that is equal

sign

times adjustment factor one point four

five five times k is eighteen of one

times p net nine ato and one point

five times spacing

s 0.8 then you press enter

yeah and then at an amount negative

2.96 that is equal to

1.455 again this time

we use negative 2.51

times uh

okay in case 80 times spacing at 0.8

okay so okay that's also how

you do for zone two and

zone three bucket hindi

highlight zone three

remember that zone 3

corners

1 and 2. so we will be using this

4 berlin loads

area computation for truss so we have

here

uh two equations that is the product of

lw and nine point five so component

minimum among two okay so

you multiply l and w

so that is 13.1 times 2.25 obviously

nothing high 9.5 square

meters so remember

that our wind speed is 290 so you have

to interpolate between

250 and 300

and then again our truss

angle is nice arrangement 7 to 27

degrees so

zones one two and three but

this time indiana

area why nine point five now

i think so we have here for

250 we have point eighty fives uh

windward and negative one point seventy

two

parasol leeward