STRUCTURAL ENGINEERING ASSIGNMENT HELP
University of the West of Scotland
STRUCTURAL ENGINEERING 3
DESIGN COURSEWORK 2015-2016
A REINFORCED CONCRETE BUILDING STRUCTURE
DESIGN CRITERIA AND INFORMATION
A Client has commissioned the design and construction of a small building, with a structural frame of the overall shape and dimensions shown below. Within the Design Team, you are the Consultant for both the structural engineering (structural frame and foundations) and the external civil engineering (external works, e.g. roads and drainage). But, in this Coursework, you will only be responsible for the design of the structural frame of this building. The Design Team also includes: an Architect, a Mechanical & Electrical (M&E) Engineer, and a Quantity Surveyor. As part of the Client’s commission, you will be producing a final Structural Design Report, which will incorporate the four Phases of this Coursework.
Requirements of the Client’s Design Brief
Main Structural Dimensions: The general plan and cross-section of the building structure are as shown below. The overall plan dimensions A and B (in metres), are between the centres of the columns. The building has two storeys, and the height dimensions between floor levels are given in terms of H. You will be assigned a unique combination of dimensions A, B, & H. Dimensions A, B, & H are presented in the tables on pages 8, 9, & 10 of this set of sheets.
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Requirements of the Client’s Design Brief
The above structural floor plan layout was chosen as the one to be designed and built, after giving consideration to the following three main design factors.
Building Function: The Client will lease the new building to an organization which will use it as a testing workshop, of a general industrial type.
Building Material: The frame is to be of reinforced concrete, which is to be highly durable.
Flexibility for Future Use: In the future, the Client wants to be able to lease the building to a different organisation, which is likely to use the building for a different purpose. The Client had asked the Design team to design the structural layout so as to optimise its potential for this future change of usage. So, longer distances, and longer beams spans, between column centres were chosen. The Client considers “Flexibility for Future Use” to be a significant design criterion.
Design Coursework Phases 1 to 4
There will be a series of four Phases of the Structural Design Coursework for this Building:
- Phase 1: Preliminary cross-section sizing of the main structural elements of the building.
- Phase 2: The Principal Structural Frame: design loadings, computer analyses, and critical evaluation of the computer output information.
- Phase 3: Computer assisted justification of the design of a Principal Continuous Beam.
- Phase 4: The production of the final drawings and the overall conclusions.
In Weeks 1, 2, 4, & 6, a lecturer will give an introduction to the respective Phases 1, 2, 3, & 4. You will submit one Final Design Report in Week.
You have been issued with this first set of Design Criteria & Information pages 1 to 13. This set is currently available on the Structural Engineering 3 module on the UWS virtual learning environment Moodle. For each of the Coursework Phases 1, 2, 3, & 4, there is an additional set of complementary design criteria & information sheets. The complementary set for each of Phases 1 to 4 is currently available on Moodle. All of these sources of design criteria & information will enable you to carry out the specified design and analysis exercises.
In Phase 1: For the specified plan layout of columns and beam spans – on page 1 above, you will do the following. First, you will estimate approximate cross-sectional dimensions for each of the typical reinforced concrete elements: a Slab, a Principal Beam, and a Column.
Second, you will also make approximate estimates of the steel reinforcement in the cross-sectionof only the continuous Principal Beam, at two critical locations along its span lengths.
In Phase 2: You will consider the corresponding Principal Structural Frame (in a vertical
plane), which includes the above Principal Beam. You will calculate two combinations of design loading on the Frame. You will use a structural analysis computer programme to assist you in the calculation of critical bending moments, shear forces and deflection-control information, for the whole Principal Frame, and particularly for only the continuous Principal Beam at Level 1 of the Frame.
In Phase 3: For only the continuous Principal Beam at Level 1, you will use a structural design computer programme to assist you in checking and justifying your Phase 1 estimates of the Beam’s cross-sectional dimensions, and of the Beam’s steel reinforcement.
In Phase 4: You will produce a cross-sectional drawing of your final design of the continuous Principal Beam element of the Principal Structural Frame. You will also produce cross-sectionaldrawings, showing final steel bending and shear reinforcement at selected critical cross-sectionsalong the spans of the Principal Beam. You will also make overall, evaluative conclusions, which will include a review and critical assessment of the whole integrated design process involved in Phases 1 to 4.
Design Criteria & Information – page 2 of 13
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The Elements of the Building Structure: General Information
The main elements of this building structure are of reinforced concrete. Some of the main types of structural element are considered below.
There is a set of illustrative ‘General Arrangement and Detail Drawings’ on pages 11 and 12 of this set of pages. These drawings are included as illustrative examples for your guidance. Reinforced concrete construction is monolithic, as all the joints (or connections) between beams, slabs, and columns, are rigid (or continuous), as illustrated by the drawings. These drawings should help you to visualise these elements and how they are inter-connected.
Columns: The building has two storeys. All columns are to have a square cross-section, with the same dimensions, from Foundation to Roof Level. Columns that are located on the external perimeter, or edges, are called ‘external columns’, and all others are called ‘internal columns’. On the plan drawing on page 1 of this set of pages, in each of the two main right-angled directions on plan, grid lines are drawn through the centres of all columns.
Beams: At each of Level 1 and Roof Level (R), beams span between columns, in each of the two main right-angled directions on plan.
The centre-lines of beams lie along the grid-lines through the centres of the columns. The span length of each beam is measured between the centres of its supporting columns. All beam dimensions (of length and of cross-section) are to be the same at both Level 1 and Roof Level. Beams around the external perimeter, or edges, are called ‘external beams’, and all others are called ‘internal beams’.
A ‘Principal Internal Beam’ is an internal beam onto which the floor slabs span. So, the span direction of a ‘Principal Internal Beam’ is at right-angles to the span direction of the floor slabs that it supports (you should also refer to the following section on Floor Slabs). The ‘Principal Internal Beam’ will be a continuous beam of three beam-elements or spans. In all of the Coursework Phases 1 to 4, it is important that you identify which beam is the ‘Principal Internal Beam’.
Floor Slabs: At each of both Level 1 and Roof Level (R), all floor slabs span between beams. Slabs are to be assumed to span only ‘one-way’, along the direction with the shorter distance between the centre-lines of their supporting beams, and at right-angles to these beams. Slab span lengths are measured between the centres of these beams.
In practice, for slab spans of 5 metres or longer, a ribbed slab normally may be a more economical option than a flat, or solid, slab. However, in this building structure, all floor slabs are to be ‘flat’, rather than ‘ribbed’. This is because some of the industrial testing processes involve concentrated loads being applied to different locations on the top surface of floor slabs, and the thinner topping slab thicknesses (e.g. 100 mm) of a ribbed slab would have inadequate punching shear resistance. The thickness of all slabs is to be the same at both Level 1 and Roof Level (R).
Column Foundations: At the bottom of each column, there is to be an isolated base, or pad foundation, or found. Each found is of reinforced concrete. The top of each found is to be 500mm below the top of a 200mm thick ground bearing floor slab at Ground Floor Level (G).
‘Internal’ founds, under ‘internal’ columns, are 2.5m x 2.5m x 0.25m. ‘External’ founds, under
‘external’ columns, are 1.5m x 1.5m x 0.25m. For the purposes of only the computer analyses of Phase 2, the support joint at the bottom of each column, which is at top-of-found level, is to be assumed to act as a pinned-support-joint, i.e. as a ‘pin’ (instead of being rigid, or fixed).
Estimating the Cross-Sectional Dimensions of the main Structural Elements
Introduction: In the following sections, the method of making approximate estimates of elementcross-sectional dimensions is based on information from a book entitled “The Way We Build Now”, by Andrew Orton.
- Typical range of span lengths L …………………………….…… within the range of 5.0m to 6.6m
- Range of recommended values of the ‘Span-to-Depth’ ratio L/h …….…………… 22 to 30
- Overall Depth h (i.e. not the ‘effective-depth’ d of the slab):
- For a simply supported slab: to get h for a given L, use a lower-range value of L/h. For a continuous slab: to get h for a given L, use a mid-range value of L/h.
- Round-up the calculated value of h to the nearest 10mm.
L is the span of beam into the paper (in m or mm)
Typical range of span lengths L ………………………………… Within the range of 8.5m to 10.0m
Range of recommended values of the ‘Span-to-Depth’ ratio L/h ……………….. 15 to 23
Overall Depth h (i.e. not the ‘effective-depth’ d of the beam):
- For a simply supported beam: to get h for a given L, use a lower-range value of L/h. For a shorter-spanning continuous beam: use a mid-range value of L/h.
- For a longer-spanning continuous beam: use a lower-range value of L/h.
- If the overall depth h is calculated as being less than 300mm, use h = 300mm.
- Round-up the calculated value of h to the nearest 25mm.
- For ‘external beams’, take dimension h to be the same as that of ‘internal beams’.
In this building structure, the columns are rigidly connected to beams to form frames which provide the means of lateral stability. (This is an alternative to, e.g., the means of lateral stability being provided by solid walls, or by cross-bracing, as could be the case in a steel structural frame.)
Typical range of span heights L ……………….…………………. Within the range of 4.0m to 5.5m
Range of recommended values of the ‘Span-to-Depth’ ratio L/h ………..…….… 8 to 13
Overall Depth h (i.e. not the ‘effective-depth’ d of the column):
- For a frame for which the columns contribute to the provision of lateral stability:to get h for a given L, use a lower-range value of L/h.
- Round-up the calculated value of h to the nearest 25mm.
Submission of the final Structural Design Report
You will be required to submit only one final Structural Design Report, which will include your component reports and drawings for all of the Coursework Phases 1 to 4. This Report is to be submitted within one A4-sized file, or folder. It is to be submitted into the Engineering box in Room E106, before 4.00pm on Monday 16th November’15, which is in Week 9. (Refer to the Module Information Sheets, Section 5.3, for the required format and procedure of making this submission.)
Marking Schedule for the Structural Design Report
For this Coursework component of this module, the final total mark will be a percentage mark, in proportion to the above mark out of 200.
Your Approach to the Design Coursework
In this Fourth Year Structural Design Coursework, your approach to carrying out these design and analysis activities will be of a more open-ended nature, and will require a greater degree of personal interpretation, than was required in Third Year. In this Coursework, you are to work more independently, and with less supervision or help from the Lecturers, than was the case in Third Year. The Lecturers will be able to help you only to clarify the interpretation of a point of information, or to help redirect you if you are completely stuck at some point. The Lecturers will only carry out assessment of your submitted final Structural Design Report.
Features of the final Structural Design Report
The following are some expected general features of your Structural Design Report:
Report writing which is comprehensive and also coherent in its reporting, discussion and justification of the content being presented.
Text, and calculations, that are clear and straightforward to read and to understand.
So as to clarify and justify the main points in your Report, as and where you consider it appropriate, your reporting should include the following features:
–At each stage, and in both written text and calculations, clearly explain what you are doing, and give adequate reasons or justifications.
- –State any assumptions made, and the reasons for these, if appropriate.
- –Include references to any source documents or design standards.
- –Make relevant cross-references within your Report.
–Add commentary text or notes to clarify or amplify the points you are presenting. Add annotations and titles to drawings for this same purpose.
The Client’s Criteria for the Form and Length of the Structural Design Report
The following are criteria which should be followed in your production of your Design Report.
- The Report should be of A4 size. Drawings can be A4 or A3, but any A3 drawings should be folded to A4 size in the Report (and still be easily accessed and read).
- Excluding sections of text and drawings that are printed out from the two specified computer software programmes (i.e. GSA & the Concrete Centre TCC11 Spreadsheet), your own produced text and calculation pages should conform to the following criteria:
–Do not use less than a 12 point font size.
–A minimum outer edge margin of 2.54 cm should be used on all four edges of each page.
–In the Paragraph Section on the top Home Ribbon of Word, do not use less than 1.5 lines spacing – and leave the Before and After settings as 0.
- The Client requires that the final Structural Design Report should not be too long or too short. Your Report should have a target length that lies between 30 and 60 A4 sides-of-pages, and this includes text and drawings generated by the above two computer software programmes. You can add only two further additional paper cover sheets – one at the front, and one at the back.
- If any of the above criteria are not adhered to in the Report, a proportional penalty will be
applied by making a reduction in the overall Presentation mark for your Report.