A five-storied reinforced concrete carpark building is to be constructed in Brisbane just outside of the CBD.

EGH475: Advanced Concrete Structures Sem 2, 2023

Building Design Project 

INSTRUCTIONS

1. It is YOUR responsibility to read the briefing carefully and ask for clarifications. Pay attention to the drawings – make sure whether you can imagine the way the structure transfer loads within the building. Get this clarified early in the semester.
2. YOUR team must adhere to the norm of working as detailed in the UNIT INFORMATION.
3. The Project is required to be submitted as three (3) Design Calculations (DCs) in Weeks 5, 9 and 13.
4. Your team must SIGN-UP online in Canvas by Week 2.
5. DISCUSSIONS page in Canvas should be used for raising queries and participating in the discussion related to the project
6. ONLINE Submissions as scheduled in the UNIT INFORMATION are expected from each team.
7. If an individual is sick, late submission of group based DCs will not be permitted – SEF policies will be followed.
8. We endeavour returning marked DCs within 2 weeks of submission. Submissions later than 2 weeks, in the unlikely event of all members of team falling ill, will, therefore, be not permitted.
9. We mark the scanned hand-written calculations associated with explanations and drawings. We will only check the computer calculations (e.g., spreadsheets) if we need clarification. Therefore, submitting only spreadsheets can result in a fail grade.

Design Brief

A five-storied reinforced concrete carpark building is to be constructed in Brisbane just outside of the CBD.

This is a reinforced concrete building with post tensioned slabs and post tensioned band beams at all levels. The Typical Level (Levels 2-4) is a one-way post-tensioned slab and band beam system. The level 1 slab (due to the requirement for ceiling space over the retail/commercial areas) has been partially designed as a flat slab with drop panels so to maximise this ceiling space (refer attached drawings). The ground floor slab is slab-on- ground so the load will be transferred directly to the soil below (this part need not be designed). There are three core walls in the building. The core wall in the middle is to serve as lift, while the other two cores on the left- and right-hand side of the building will serve as stairs.

Given data:

• Building importance level: 2
• Site soil class is Be
• Concrete characteristic strength, fc’ = 40 MPa
• Yield strength of reinforcing steel, fsy = 500 MPa
• Density of Reinforced Concrete = 2500 kg/m3
• Exposure classification from AS3600-2018
• FRP: From NCC 2019
• Superimposed dead load (SIDL) on the floors is 0.25kPa
  • Façade permanent load is 0.5kPa and the height of façade walls is 2m (excluding perforations)
  • For the roof level, there is 50mm thick of additional concrete cast as part of the slab to create the needed slab falls for water drainage. Consider all other loads similar to the typical level.
  • The flat slab portion of Level 1 can be considered as 240mm thick
  • Core walls are 200mm thick
    • Assume post tensioned losses are 10% and 20% for initial and long-term losses, respectively
    • The Ground Level of the carpark is set at an RL = 31.2m
    • Assume data not supplied, however, explain the reasons of the assumed values

Problem Statement

DC 1: Assessment of vertical loads

WEIGHTING: 15%

SUBMISSION TYPE: Online through Canvas DUE DATE: by 11:59pm, 27 August 2023

Using the drawings provided for the proposed carpark building near Brisbane CBD, undertake the following tasks:

1. Using AS/NZS1170.0 and AS/NZS1170.1 draw loading plans for this building. On each floor plan, nominate the superimposed dead loads and the imposed loads.
2. Using the span to depth ratios from the lectures, determine the preliminary sizes of the post tensioned one-way slab and band beams of the typical floor level and draw a structural floor framing for this floor. Consider the band beams parallel to Grids A to F in horizontal direction.

1. Calculate G and Q loads for all the columns and structural core walls on all floor levels using tributary area method. Calculate the resultant loads at the bottom of the columns and core walls on the top of the ground floor slab.

Instructions:

• Dimensions of the core walls should be as per original drawings provided.
  • Show detailed calculations for vertical load transfer process on column at Grid D4 and Lift core wall. The loads of other columns and structural walls can be summarised in a table.
  • Assume any missing data and briefly explain the reasons of the assumed values.
    • Mention all the relevant clauses of the code at the left/right margin throughout the design so that they can be checked.
    • Include loading plans of all floors, structural framing plan of typical floor and tributary area plan (for columns and walls) in your submission.
    • All calculations should be well presented. If you are using spreadsheet for load/ analysis/ design calculations, you still need to show a set of safe design hand calculations clearly. Spreadsheets will not be marked.

DC 2: Design and detailing of post tensioned one-way slab and band beam system

WEIGHTING: 15%

SUBMISSION TYPE: Online through Canvas DUE DATE: by 11:59pm, 24 Sep 2023

Using the drawings provided for the proposed carpark building near Brisbane CBD, undertake the following tasks:

1. Analyse the Typical level post-tensioned (PT) one-way slab on grid 4 (between grids B and E). Consider the permanent dead loads, superimposed dead loads and imposed loads calculated for DC 1 for this analysis. Use the analysis methods from Section 6, AS3600 to determine the design actions. However, given the spans either side of grids B and E do not comply with the 1.2 ratio for the span lengths, negative moment on Grids B and E shall be FdLn2/10.5.
2. Analyse the Typical level post-tensioned band beam on Grid C (between grids 4 and 7). Consider the permanent dead loads, superimposed dead loads and imposed loads calculated for DC 1 for this analysis. Use the analysis methods from Section 6, AS3600 to determine the design actions.

1. Design the analysed PT one-way slab and PT beam in Task 1 and 2, respectively for the critical forces and determine the following:

• Number of strands required for the slab and the beams using the load balancing method.
• Stress checks for the critical locations at transfer and service stages.
  • Ultimate moment capacity check and design of non-prestressed reinforcement if needed.
  • Design the shear reinforcement for the beams only at the most critical shear section.
  • Sketch the tendon profiles and reinforcement on the structural plan.
  • Draw the beam elevation and section.

1. Using AS3600 and considering the permanent dead loads, superimposed dead loads and imposed loads calculated for DC 1, design the reinforced concrete column on Grid D4. The column does not take any bending moment from the band beam (pin connection), however, consider the minimum bending moments as per AS3600-2018.

Instructions:

• Balancing Load = 80% of self-weight.
• Use 12.7 super strands for the post-tensioning design.
  • Mention all the relevant clauses of the code at the left/right margin throughout the design so that they can be checked.
  • Use sketches to clearly display the various loading stages, SFD and BMD, tendon profiles, PT and reinforcement detailing for each member.
  • The reinforcement design should be clearly documented with the use of construction quality sketches/ drawings.
    • Take durability and fire into account as per the requirements of the AS3600-2018 and check whether the provided element sizes are sufficient.
    • All calculations should be well presented. Even if you are using spreadsheet for design calculations, you should present a set of design hand calculations clearly. Spreadsheets will not be marked.
    • Assume data not supplied, however, explain the reasons of the assumed values.