Learning outcomes

1. Identify geotechnical factors, substructures, and structural systems for medium and large buildings.
4. Create technical sketches for medium and large building projects.

Case Study Investigation

This body of work will be a representation of all your study and research of medium and largem buildings. The main body of work will include research, sketching and short answer questions. All questions are related to the fictional ‘Lichfield Street Fire Station’. Drawings of fire station building have been provided.

Important: All details can be hand drawn and/or ruled, or CAD produced. Use appropriate scale and/or proportion. Clearly annotate all parts of your detail. Details must have a title and be presented in order as set out in the tasks. All details are to be scanned and ‘inserted’ into your document. Do not take photos of your details.

All referencing is to be APA 7th Edition.

This assessment leads to Assessments 2.

Overview

This building block (named ‘Lichfield Street Fire Station’) is in Concept Design Stage. A building consent for the structure has been issued to the client. You have been asked for advice on the design feasibility to fit out and complete the building. The building site is located on the corner of Lichfield / Madras Streets, Christchurch.

The drawings contained in Appendix 2: Fire Station Drawings include:

• A1 Site Plan
• A2 Basement Floor plan
• A3 Ground Floor plan
• A4 First Floor plan
• A5 Second Floor plan
• A6 Roof plan
• A7 Section A-A (Structure Only)
• A8 Section B-B (Structure Only)
• A9 Section C_C (Structure Only)
• A10 Section D-D (Structure Only)
• A11 Elevation North
• A12 Elevation East
• A13 Elevation South
• A14 Elevations West
• A15 3D and Detail.

Construction

The structure is essentially column (with a shear wall on the east of structure) and concrete floor construction (floor construction undecided). All total floor heights are 3000mm. (see Sections for clarification).

It has a long-span structure (Portal Frame) attached to the West face of the Office Block.

All joinery and curtain wall system types and style are currently undecided on the South face of the building. (Refer to all floor plans for location).

All internal wall locations are as outlined on Floor plans. Construction and finishes / fittings  are all undecided.

• All details can be hand drawn and ruled, or CAD produced. Use appropriate scale. Clearly mark all details with titles and present in order as set out in the tasks.

Task 1: Ground Conditions: Sub-structure Ground Conditions

Your task is to investigate the sub-structure ground conditions pertaining to the fire station.

• Start by referring to the section drawings GXS-CBD-13, provide an overview of how the geology in this section was formed in relation to the geological history of New Zealand.
• Explain in a paragraph why a soil investigation report is important for [refer to this case study].
• Identify five key factors that could be determined from a soil investigation report that would assist in the tendering and construction of the project.
• Produce a borehole log of the sub-soil strata in the proposed location of the fire station using the cross section drawing GXS-CBD-13. This must be to scale and include graphic illustrations of the different subsoils.
• Describe what you would expect the approximate bearing capacities of each sub-soil type are using the borehole log.
• Describe and illustrate the difference between permeability and porosity. Give
  examples of the types of soils for each. Reference could be made to the subsoils found borehole in question 1 – list item 4. Please provide examples.

(Task 1: Word count guideline: 300 words)

Task 1: Total (12 marks)

Task 2: Foundations and Deep Foundations

Part 1: Foundation methods.

Based on the drawings provided of the proposed Fire Station Project, your task is to provide foundation solutions in the specified locations noted below.

You must include the following, as per the specified location.

• A plan sketch of your proposed solution with sections where applicable. Include annotations.
• Reinforcements used in commercial foundations: type, size, and location.
• Describe the selected foundation type in relation to the type of load transferred from the structure.

To be provided for the following locations:

A. Portal frame foundation:
In addition to providing the information detailed above, for a portal type
foundation calculate the size of a foundation pad under specified loadings and
provide feedback on the outcome. See attached loading conditions.
Refer to Appendix 1 Assessment 1 -Task 2. 1A -Pad Foundation

B. Basement foundation:
In addition to providing the information detailed above, explain the importance
of evenly distributing loads under a basement foundation.
Discuss the potential risks of an unsuitable load bearing capacity under the
basement foundation.

C. Office and apartment building with no basement:
In this scenario, the client has decided to omit the basement. They are expensive and timely to construct. This will be covered in more detail in Task 3. In this solution the foundation will be a combination of foundation types, dependent on the loads from the structure. In addition to providing the foundation solution detailed above describe the types of loads being transferred from the structure to the foundation.

Part 2: Deep foundation methods

Your task is to evaluate the various construction methods used for deep foundation systems pertaining to the fire station.

A. Discuss the specific conditions that require the use of a deep foundation system. With the borehole log from Task 1 as reference, suggest a depth for a viable deep foundation solution and provide justification.

B. Industry professionals classify deep foundation systems into two types: replacement and displacement. Explain how each system transfers load to the subsoil or subsurface rock formation. Include sketches and/or illustrations.

C. Select a replacement or displacement piling system that meets the project’s requirements and that the project’s office and apartment section approves.

• Assess the project’s structure and ground conditions.
• Outline the pros and cons.
• Explain the installation process (use sketches/illustrations).
• How does your piling method connect to the foundation system to provide
  lateral restraint?

(Task 2: Word count guideline: 300 words)

Task 2: Total (21 marks)

Task 3: Basement Construction

1. Your task when considering the basement construction of the fire station project is to provide sketches or illustrations where appropriate to describe:
   • Evaluate the pros and cons of incorporating a basement in a building,
     specifically within an urban context.
   • Describe a method of supporting excavation sites during construction using current H&S regulations. Include the approximate depth of supported soil during excavation.
   • Describe a suitable method of controlling groundwater and surface water
     during construction. When is the appropriate time to remove the dewatering system?
2. Provide a brief description of a typical in situ formwork system used in basement wall construction.
   • Include annotated sketches and or illustrations to support your answer.
     Includes, but is not limited to:
     • Formwork material.
     • The method of tying the forms.
     • Supporting formwork and plumbing forms.
     • Describe how to release the forms from the concrete.
   • Provide a description with annotated sketches of the following:
     • A method of preventing water penetration into a completed
       structure.
     • Provide details on how to prevent water penetration at the
       formed construction joints.

(Task 3: Word count guideline: 500 words)

Task 3: Total (20 marks)

Task 4: Stability of Structures: Portal Frames

1. Your task is to provide a section drawing of the Fire Station Building’s portal frame structure. (Refer to Section B, p. 8).
   You can enlarge sections/details. Create a freehand sketch of this section, including annotations and maintaining proportions. Information to include:
   • Identify the key structural or construction components.
   • Provide a brief description of each critical component and its primary
     purpose.
   • Please explain the connection between structural elements.
     (Refer to details marked 1 on p. 8).
2. To reinforce the west elevation facade, cross bracing must be installed between the 250UC stanchion legs. (Refer to the West Elevation, p. 14 of the drawings). Your task is to design a ‘concentric’ bracing system for this elevation. Create an elevation sketch showing your proposed bracing. Please include a brief explanation of why you selected this configuration.

(Task 4: Word count guideline: 200 words)

Task 4: Total (12 marks)

Task 5: Stability of Structures: Office Structure

1. Your task involves presenting a concise explanation and differentiation of moment frame, braced frame, and shear wall construction.
   Based on your research on the pros and cons of each construction system in Topic 4, determine the most appropriate system for the Fire Station Office Building and explain why.
2. To counteract horizontal forces, precast panels are implemented in the office building’s east and west elevations. Explain why eccentrically braced frames are ideal for the Office building’s north and south elevations.
   • Calculate how many braced bays each elevation requires.
   • Provide a solution for limiting the large forces exerted on the structural
     frame.
3. You are required to take a photograph of a building, either under construction or completed within the last five years, that prominently features the bracing element. Provide a description of the bracing type/system. Provide a detailed sketch or illustration that depicts and labels how the system is connected to the structure (beam or column).

(Task 5: Word count guideline: 200 words)

Task 5: Total (10 marks)

Task 6: Superstructure: Structural Pre-cast Concrete

The precast panels on the north elevation of the portal frame building are cast onsite. All remaining precast panels are manufactured off-site.

1. Please answer the following questions regarding these precast panels.
   • Explain the advantages and disadvantages of manufacturing precast panels on and off site?
   • Identify two details that are appropriate for connecting the precast (on or offsite manufactured) to the foundation.
   • In comparison to other building materials, what are the advantages of precast panels?
2. Provide a detailed description of how the precast panels are made on site. Include where the panels would be made and the lifting device for placing them. To support your answer, you can use generic methods and illustrations.

(Task 6: Word count guideline: 200 words)

Task 6: Total (10 marks)

Task 7: Superstructure: Superstructure Construction Methods

1. This task relates to the first floor, Office 1 floor plate. Refer to the attached drawings for the location. The superstructure is constructed using structural steel. Please provide the following information:
   • Provide the shear connection detail of the horizontal main steel member to
     the precast shear wall.
     (Shown as detail 2 on the drawings).
   • On the drawing, provide the moment connection detail of the horizontal
     main steel member to the vertical steel member.
     (Shown s detail 2 on the drawings).
   • Provide the splice detail for vertical continuity of a structural steel column.
   • Describe with sketches and or illustrations two methods for constructing the first floor. The precise location is indicated by the shaded area on Page 4. Please include section and plan drawings that show:
     • Span and spacing of both flooring systems.
     • Main and secondary steel structures support both systems.
     • Drawings showing the structural steelwork supporting the flooring system.
     • Concrete topping details, including reinforcement.
     • Connections to structural steel and precast units. Include edge details where applicable.

     Using appropriate manufacturer literature will support your answer to d). All drawings should be annotated and dimensioned where relevant.

2. Describe how damage mitigation methods could be applied to this structure (after a seismic event), using sketches and or illustrations.
   Provide a description of alternative structural solutions for structural frames other than steel.
   If applicable, provide research information. Manufacturer’s literature must be cited for any construction method. Written text must be in your own words.

(Task 7: Word count guideline: 300 words)

Task 7: Total (15 marks)

(Assessment 1: Word count guideline: 2000 words)

Assessment 1: Total (100 marks)

Marking schedule

Task 1: Sub-structure Ground Conditions

Task 2: Foundations and Deep Foundations