EBOOK on Seismic Analysis and Design of RC Building

I created an ebook for beginners wanting to learn Seismic Analysis and Design of RC Building Using STAAD and Spreadsheet.

Feel free to download draft copy of this..just send a message. FREE EBOOK

DESIGN OFSTRUCTURE USING STAAD AND SPREADSHEET

Design and analysis of structure is normally done in the following procedure:

1. Setting up Design criteria
2. Modeling of structure in STAAD
3. Adding loads in structure
4. Design of Gravity Members
1. One way slab
2. Two way slab
3. Intermediate Beam
5. Design of Seismic resisting Members
1. Girder
2. Column
6. Design of Foundation
7. Compiling the result in a structural design report for submission in city hall.

PART 12- DESIGN OF ISOLATED FOOTING USING EXCEL FROM STAAD RESULT

This video shows how to design an isolated footing using excel from load result in staad.

This video below also shows isolated footing design using RCDC and verified with spreadsheet.

PART 5-GENERATING AUTOLOAD COMBINATION AND VERIFYING STAAD RESULT WITH SPREADSHEET

This shows how important the ff:

1. Defining load cases type will help you generate autoload combination according to your specified code.
2. Seismic weight depends on what dead load or mass you specified on the seismic definition.
3. Spreadsheet verification of seismic base shear accoring to NSCP/UBC 1997.

PART 6-DESIGN OF GRAVITY MEMBERS

This shows design of the following gravity members:

1. One way slab
2. Two way slab
3. Intermediate Beam

PART 7-DESIGN OF GRAVITY MEMBERS

This shows design of the following gravity members:

1. One way slab is designed using the spreadsheet.
2. Two way slab is designed using the spreadsheet.
3. Stringers or Intermediate Beam is designed using spreadsheet.

PART 8-DESIGN OF GRAVITY MEMBER(INTERMEDIATE BEAM)

Intermediate Beams or stringers are also gravity members that directly carries the slab loading and transferred them to girder.

PART 9-DESIGN OF GIRDER

The Girders which span from column to column carries loading from the intermediate beam and also part of the seismic resisting member of the building. This video shows the design of girder using the spreadsheet. Staad does not completely give a detailed design of girder because there are many considerations especially Code provisions in earthquake. Thus, a spreadsheet is important to guide the designer. For example, the minimum NSCP width of girder 250mm is not one of the parameter in staad.

PART 10-DESIGN OF GIRDER PART 2

Design of girder part 2.

This video also shows girder and intermediate beam design using RCDC and spreadsheet.

However, during further investigation of structure, revised design is done as shown below.

PART 11-DESIGN OF COLUMN

This video shows how to design or investigate the column using spreadsheet from analysis result in STAAD.

This video below shows column design using RCDC and verified in spreadsheet.

PART 3-ADDING DEAD LOAD, LIVE LOAD AND EARTHQUAKE LOAD IN STRUCTURE

This video shows how to add dead load, live load and earthquake load in your structure. It shows how important the staad editor in modeling because understanding the editor will help you edit the model quickly compared to doing it through GUI.

PART 2-SETTING UP DESIGN CRITERIA

Part 2 of design of building using staad and excel. Setting up the design criteria using a spreadsheet. Note that design criteria must be consistent with design drawings and design specifications.

PART 1- STAAD MODELING OF BUILDING

This is a sample staad modeling of 4 storey building. There are many easy ways to model building in staad and its in this video.

COLUMN INTERACTION DIAGRAM

In the design and investigation of concrete column, interaction diagram is required. This is a plot of Axial load, P capacity versus Moment, M capacity in a certain axis of the column.

The image below shows an interaction diagram indicating Nominal capacity and Ultimate capacity of the concrete column. The single dot is the specified load required in the column from the structural analysis. The load required plot should be inside the interaction diagram curve. Note that the interaction diagram is a work in progress to date.

This is the overview of the spreadsheet.

The user will only input on the following yellow filled cells:
1. b = width of the column along x axis
2. h= height of column along y axis
3. cover = extreme tension layer distance from center to outermost cover of column
4. As1= area of single rebar used in both extreme tension layer and compression layer, 3= number of rebar in both extreme tension and compression layer
5. effective depth from outermost compression concrete to extreme tension layer
6. As2 = area of single rebar in zone 2, 2=number of rebar in zone 2, 249= effective distance of zone 2 rebar to extreme compression concrete, As3=area of single rebar in zone 3, 2=number of rebar in zone 3, 491= effective distance of zone 3 rebar to extreme compression concrete..
7. fy= rebar yield strength
8.fc = concrete compressive strength

After inputting all those values, an interaction diagram is generated for up to 5 layers of rebar in a concrete column. The corresponding Pu and Mu required is also plotted if you input them.

Having this kind of spreadsheet will allow you to easily investigate the column for a number of load combinations of P and M from dead load, live load and earthquake load. Also, changing the parameters like rebar area, depth of each zone of rebar and number of rebars in each zone are easier compared to doing it in manual calculation.

The video below shows verification of result for 4 rows of rebar in column.

The video below shows a verification of result from interaction diagram.

This video shows how to input actual column rebar layout from column schedule and investigating the capacity from set of load forces from different load combinations:

Reinforced Concrete Design Laboratory

To ensure that students will learn how to design in a proper sequence and with task to finish on time, a monitoring checklist is required. See below for sample checklist I used..

As you observe, architectural plans should be submitted first followed by the Structural Plans. From the structural plans, students should be able to look for the design criteria and encode in the spreadsheet. Most of the values here are obtained from the General Notes or first sheet of the Structural Plan. They will then refer to NSCP 2010 to verify the values and set constant parameters like the following:

1. Beta factor of concrete from assumed Fc'
2. minimum reinforcement ratio from assumed fy and fc'
3. maximum reinforcement ratio

From structural plans, loading distribution plan and loading designation plan should be generated. This exercise will help student realize on loading effects on members and will determine by inspection which girder or beam will carry the most load.

There will be four major loading criteria for student to analyse:

1. Dead Load
2. Live Load
3. Wind Load
4. Earthquake Load

Gravity loads like Dead Load and Live load will be analyzed by Moment Distribution Method while Wind Load and Earthquake load by Factor Method.

Loading combinations are then post processed after analysis to obtain the Governing load combinations to be used in Design of Elements.