sub-division design assignment 2011

8/6/2019 Sub-Division Design Assignment 2011

http://slidepdf.com/reader/full/sub-division-design-assignment-2011 1/15

SUBDIVISION DESIGN AND ESTIMATION GROUP PROJECT

2104ENG CONSTRUCTION ENGINEERING

PROJECT BRIEF

General Task Description

You are working for a consulting engineering firm whose client (Mr Saied Maboudi) isplanning to sub-divide and develop a large plot of land. The contour plan and land plotdimensions are illustrated in Figure 1.

The client’s brief requires a feasibility design report with cost estimation for the land

development into residential lots including all associated roads, services, amenities andlandscaping.

The client is seeking to make a profit from this investment in excess of 20%. The land outlaycost him $1.2 million, which was borrowed from a bank at a 7.5% interest rate. All additionalworks associated with the development will be funded through a credit facility also at a bank interest rate of 7.5%. Your financial assessment needs to consider the time period to developthe land (i.e. feasibility, detailed design and tendering, construction) as well as the marketingand sales period until all lots are sold (e.g. 1 year sales period). The local government haszoned the land ‘Residential’ with an average development block size of approximately 600m2 expected, with individual blocks allowed between 400-1100m2. Some parkland is required inthe sub-division in order to meet local government standards.

In order for the client to proceed with the development, he needs to receive a positive

feasibility study that includes a workable schematic design, works estimate and profitabilityassessment. This is the task of the design team (i.e. you).

Project Deliverables

1. Group Formation: Form a group of exactly five (5) persons (voluntary groupformation), which will serve as the feasibility design team. Create a group name (e.g.Ginger Beers Consulting Engineers). All members will be required to make an almostequal contribution to the project or penalties may be incurred to individual membersproviding limited effort. Group formation is not the responsibility of the client. You

are required to indicate on the assignment cover sheet which member(s) of the groupwere responsible for the production of each of the report sections. Each member of the group will receive the overall mark for the report, based on even contributionsfrom members (i.e. 20% each).

2. Sub-division Schematic Design: Complete schematic design for the sub-division. Aschematic design ensures that the sub-division is workable; it is not a detailed designfor specific elements (e.g. stormwater pipe design). Detailed design of specificelements is beyond the scope of this feasibility design report. The mains aspects to becovered in the schematic design/specifications section, predominately displayed asdrawings and basic specifications, include: (1) sub-division layout including

precincts; (2) road layout and cross-section; (3) stormwater layout; (4) earthworks(i.e. cut and fill) diagram and calculations including retaining wall locations and



standard cross sections; and (5) services layout (i.e. electricity, water andphone/cable). Well presented drawings are required (AutoCAD is not mandatory fordrawings). The specific requirements of these sections are described briefly below andwill be further discussed by the client in meeting periods. As a final note, this projectonly covers land development and not housing (i.e. land sales only).

3. Project Cost Estimate: Once you have completed a schematic design and drawings, aswell as basic specifications, you will be able to build a cost estimate for the project.The first step to building a cost estimate is to create a Work Breakdown Structure(WBS) for the project; this will help you build the estimate. The cost estimate willneed to cover all aspects associated with the project, with the significant portion of work being to estimate the labour, equipment and materials required to completeconstruction works. Given that this is a feasibility study, your estimates can only bemade based on best available information. Rawlinsons Construction Guide providesgood cost accounts for different activities and is a good reference document.Remember that your estimate should include as many periphery activities/

considerations required for completing construction projects (e.g. site establishment,traffic control where applicable, weather lost time, etc.).

4. Financial Assessment: Once a sufficient cost estimate for the different phases of theproject has been developed, you will need to conduct a financial assessment. Theclient is seeking at least a 20% profit margin so examine whether this is feasible. Youwill need to apply your engineering economics principles to complete this assessment,and consider the accumulation of interest into your financial model. Remember, thatall lots will not be sold in one day and there may be some sales commissions that needto be paid, so the return from individual lots will not necessarily be the cumulativesales price. Please indicate the profit to the client from this investment and make arecommendation on whether he should proceed with the project.

Specific Project Inclusions

Earthworks and development layout

By using the borehole logs and the contour profile you need to determine, with justification,the required cut and fill for the site. Also, boreholes will inform you of the type of materialbeing excavated, thereby assisting with earthworks productivity calculations.

Suitable structurally sound soil material must either be reached via cut or fill with appropriate

compaction for building areas and roadways. Potentially, suitable fill may also be imported tothe site where required. Suitability requirements of the soil may need to be interpreted fromthe supplied information or researched in terms of council standards (i.e. Gold Coast CityCouncil), Ausroads Guidelines, Australian Standards (AS 1726-1993), and/or Earthwork Guideline AS3798.

Earth retaining structures may be required where excessive slopes exceed standards. You willneed to examine design standards for types of retainers that are suitable for different heightsof retained earth and indicate where they are located in your schematic design.

The type of earthworks machinery required to complete earthworks needs to be explained and

justified and their time and cost requirements estimated. Earthworks include but are notlimited to: general levelling of the site, excavation, road and site preparations, and digging of



all services. Naturally the overall efficiency of the plant equipment must be considered. Youmay wish to use a unit rate approach for some earthworks calculations (unit rate e.g. $/m3 andquantity e.g. 265m3) and a lump sum cost for others (earthworks survey $4,200).

Services (water, sewage, electrical, communications)

Services to be considered include all those typically required for a development of this type,including: stormwater pipe network (lot and road), sewage, reticulated water, electrical andcommunication. Stormwater flow and drainage should consider the natural contours of theland. Stormwater can be channelled using both overland and underground methods;whichever is the most appropriate. Do not overly consider links with nearby lots adjoiningyour development for the purposes of this design.

Maximum gradients and dimensions of stormwater and sewage pipes should be in accordancewith the appropriate guidelines and AS (Australian Standard). You are able to make yourown determinations on final connections to both stormwater and sewage bulk mains. Allstormwater drains/pipes must be appropriately drawn on your schematic layout plan. You

may consider having stormwater detention areas if this is appropriate for the site conditionsand will meet appropriate regulations.

Water and wastewater service pipes are connected to each lot. Supply lines, at requireddepths and gradients are to be indicated on the site plan. Similarly, electrical andcommunication lines are to be indicated on the site plan. Stormwater and other surface waterdrainage by underground piping or surface diversions accordance AS/NZS3500. As afeasibility design, you are not required to design pipes, electrical, etc. Instead you canindicate where these services will be provided on a layout plan and refer to standard drawingsand specifications. Assumption for typical services sizing is expected, as this is purely thefeasibility design stage of the project; do not tackle detailed design.

Development local roads

Assume all roads are to have typical kerb and channel of appropriate dimensions andstructured to allow adequate drainage. Stormwater drainage inlet locations can be determinedbased on contours, but number and spacing can be assumed. The road surface is to be normalbitumen laid on suitable sound ground base as per Gold Coast City Council local roadguidelines. The design of the roads should consider aspects such as minimum radius of curvature, minimum widths, turnaround requirements, and crest /dip radii as per relevantMain Roads/Ausroads/ Council guidelines. All roads should be clearly drawn on the site plan.

Schematic design and drawings (including ‘basic’ specifications) All site plans and designs should be produced professionally using hand or a softwaredrawing package. AutoCAD drawings are not mandatory but could be considered by theteam. It would be expected that you have ‘schematic’ design drawings covering the following

elements of design:

Sub-division lot layout and size schedule (including parks, easements, etc.)

Earthworks including cut and fill areas (including specifications e.g. retainingstructures)

Stormwater drainage (overland flow and pipe network)

Sub-division road network and connection to main road(s)

Water and sewage services schematic design and specifications

Electrical and communications services schematic design and specificationsSub-division landscaping plan (only development and not individual lots)



Standard sections from appropriate codes/standards/guidelines for key developmentcomponents (e.g. retaining structure, roads, services, etc.)

Project cost estimateOnce you have completed your schematic design and layout drawings, you will need to build

a ‘feasibility’ estimate for the project. This is not a detailed estimate for final contract pricingbut for determining whether the development should proceed or not. The first step to buildingthe cost estimate is to create a work breakdown structure (WBS), starting with the mainactivity categories and then individual tasks underneath (search Google for examples of WBS). As this is a feasibility assessment you will not be itemising individual bolts, so build astructure that is realistic for the expected scope of the report. Once you have created yourWBS, proceed to determine resource requirements for each task (i.e. labour, machinery,materials, etc.) and quantities (i.e. volumes, time estimates, etc.). Resource and quantumhelps inform the estimation. You may wish to develop general unit rates for each major task in order to simplify calculations (e.g. road construction rate in $/m2 of road multiplied by thearea of road in development). Some activities could be estimated with a partially justified

lump sum where they are difficult to estimate. The Rawlinsons Guide or Civil ConstructionTender documents are excellent for getting a feel for the cost of construction activities. Makerealistic assumptions where information could not be sourced; don’t get bogged down in

excess detail for your estimate. Once you have completed the estimation process, build anestimate summary for the cost of the development works. Note that site civil developmentcosts only form a portion of the total cost for the project. Microsoft Excel is sufficient for theestimation process.

Project financial assessmentThe project financial assessment can be completed in Microsoft Excel and cover the entiredevelopment life cycle (conception to final sale, and potentially a post-completionmaintenance period). Basic engineering/financial economic principles should be applied.Aspects to be considered in your financial assessment include, but are not limited to thefollowing elements:

Bank interest rate on annual average loan amount

Inflation rate

Project timeframe

Feasibility and detailed design phase costs

Land holding costs

Civil construction costs and any relevant development charges considered

Sales period, land sales prices for lots, sales commissions, etc.

Break even and profitability assessments

Assignment format and general requirementsYour final submission must be in a standard technical report format, with the usual basicinclusions:

Technical Report cover page

Student contribution statement

Executive summary (1 page)

Contents page, list of figures, list of tables

Technical report main body

Conclusion and recommendationsReferences



Figure 1. Site contour plan

BH4

200 m

BH1

BH2

BH3



APPENDIX A. GEOTECHNICAL REPORTS

D.I.G. BOREHOLE

Geotechnical Engineering Services

Suite 1, Unit 460 Riverview RoadNerang 4211Ph: 55 555555

Client: I.M. Multirich Borehole ID: BH1

Project: Random site location, Gold Coast City Job Number: 123

Equipment: Multi Bore 101, Bore Diam = 100 mm Date: 10/01/11

Depth (m),

RL 27 m

Material

Description

Consistency Sample

Test/Results

Additional

Information

0_____

0.5 _

_

Topsoil :

Mid grey,containing somesand and organicmatter, slightlymoist.

F SPT, N = 6 max FillMC = 8%pH = 5.6Wt = 1.9 t/m3

_

_

1.0 __

___

1.5 _

SYC :Grey brown,moist.

St SPT, N = 22 av AlluviumMC = 18%pH = 5.0Wt = 2.3 t/m3

_

_

_

_ 2.0_____

2.5 _____

3.0

SDC :

Grey, moist, sand

content fine tomedium grainsize.

VSt SPT, N = 30 AlluviumMC = 22%

pH = 4.9Wt = 2.5 t/m3

_

_

__

3.5 __

___

4.0 _____

4.5

GW – XWGrey and brown,

medium grained,slightlymetamorphosedsedimentary rock,generally displaysengineeringproperties similarto very stiff siltyclay to dense siltysand.

MD SPT, N = 45 Wt = 2.4 t/m3

_

___

GW – HW

Grey and brownwith iron staining

D SPT, N > 50 Wt = 2.3 t/m3



5.0 __

___

5.5 –

_ ___

6.0 -_

___

6.5 __

___

7.0

throughout.Angular defectswith clay coated.

_

___

7.5 __

___

8.0 __

_

__

8.5__

___

9.0 _____

9.5 _____10

GW – MW:

Brown grey,lightly ironstained, alongdefects.

D SPT, N > 50 Wt = 2.35 t/m3

Consistency / Density / Rock Strength

VS – Very Soft Hd - Hard VL – Very Loose VL – Very Low

S – Soft El – Extremely Low MD – MediumDense

M - Medium

F – firm Lw = Low D – Dense VH – Very High

St – Stiff H – High VD – Very DenseVSt – Very Stiff L – Loose Fb - Friable



D.I.G. BOREHOLE



Client: I.M. Multirich Borehole ID: BH2Project: Random site location, Gold Coast City Job Number: 123


Depth (m),

RL 18 m

Material

Description

Consistency Sample

Test/Results

Additional

Information

0_____

0.5 ___

1.0 _

Topsoil :

Dark grey,containing somesand and organicmatter, moist.

S SPT, N = 3 max FillMC = 11%pH = 5.0Wt = 2.01 t/m3

_

_

_

_

2.0_____

2.5 _

SYC :Grey brown,with creamstreaks, moist.

F SPT, N = 19 av AlluviumMC = 23%pH = 4.9Wt = 2.35 t/m3

___

_

3.0 __

_

_

_

3.5 __

___

4.0 _

SDC :

Dark grey, moist,sand content fineto medium grainsize.

VSt SPT, N = 28 AlluviumMC = 21%pH = 4.8Wt = 2.45 t/m3

_

___

5.0 __

___

5.5 – _

___

6.0 -

GW – XW

Dark grey andbrown, mediumgrained, slightlymetamorphosedsedimentary rock,generally displaysengineeringproperties similarto very stiff siltyclay to dense siltysand.

MD SPT, N = 43 Wt = 2.35 t/m3

__

GW – HW D SPT, N > 50 Wt = 2.4 t/m3



__

6.5 __

___

7.0_

___

7.5 __

___

8.0 __

__

_8.5__

___

9.0 __

___

9.5 _

Dark grey andbrown with ironstainingthroughout.Angular defects

with clay coated.

__

__

10 _____

10.5 ______

11.0 –

GW – MW:

Dark browngrey, lightly ironstained, alongdefects.

D SPT, N > 50 Wt = 2.35 t/m3

Consistency / Density / Rock StrengthVS – Very Soft Hd - Hard VL – Very Loose VL – Very Low


M - Medium


St – Stiff H – High VD – Very Dense

VSt – Very Stiff L – Loose Fb - Friable



D.I.G. BOREHOLE





Depth (m),

RL 27 m

Material

Description

Consistency Sample

Test/Results

Additional

Information

0_____

0.5 _

Topsoil :

Light grey,containing sandand organicmatter, slightlymoist.

St SPT, N = 12 max FillMC = 5%pH = 5.4Wt = 1.8 t/m3

_

___

1.0 _

SYC :Grey to dark grey, somemoisture.

VSt SPT, N = 28 av AlluviumMC = 14%pH = 5.5Wt = 2.4 t/m3

___

1.5 __

_

_

_

2.0_

SDC :

Grey, moist, sandcontent fine tomedium grainsize.

VSt SPT, N = 32 AlluviumMC = 23%pH = 5.0Wt = 2.5t/m3

_

_

_

_

2.5 __

___

3.0 ____

_3.5 _

GW – XWLight grey andbrown, mediumgrained, slightlymetamorphosedsedimentary rock,generally displaysengineeringproperties similarto very stiff siltyclay to dense silty

sand.

MD SPT, N = 48 Wt = 2.45 t/m3

_

___

4.0 __

___

4.5 – _

___

GW – HW

Grey and brownwith iron stainingthroughout.Angular defectswith clay coated.

D SPT, N > 50 Wt = 2.35 t/m3



D.I.G. BOREHOLE





Depth (m),

RL 18 m

Material

Description

Consistency Sample

Test/Results

Additional

Information

0_____

0.5 __

_ _

1.0 __

_

Topsoil :

Dark grey,containing somesand and organicmatter, moist.

S SPT, N = 3max

FillMC = 14%pH = 4.9Wt = 2.2 t/m3

__

1.5 __

_

_

_

2.0__

___

2.5 _____

3.0 __

_

_

_

3.5 _

SYC :Light grey withred brownstreaks, quitemoist.

St SPT, N = 18av

AlluviumMC = 25%pH = 4.8Wt = 2.2 t/m3

_

_

_

_

3.5 __

___

4.0 __

___

4.5 __

SDC :Charcoal grey,moist, sandcontent fine tomedium grainsize.

VSt SPT, N = 32 AlluviumMC = 23%pH = 5.0Wt = 2.5 t/m3



___

5.0 __

__

_

5.5 –

_

___

6.0 -_

___

6.5 __

___

7.0 __

___

7.5 __

___

8.0 _

GW – XWCharcoal greyand brown,medium grained,slightlymetamorphosedsedimentaryrock, generallydisplays

engineeringproperties similarto very stiff siltyclay to densesilty sand.

MD SPT, N = 48 Wt = 2.45 t/m3

_

___

7.5 __

___

8.0 __

__

_8.5__

___

9.0 _____

9.5 ___

__

10 _

GW – HWCharcoal greyand brown withiron stainingthroughout.Angular defectswith clay coated.

D SPT, N > 50 Wt = 2.4 t/m3



____

10.5 ___

___

11.0 _____

11.5 _____

12.0 __

___

12.5 ______

13.0 _____

13.5_____

14.0 _

GW – MW:Dark browngrey, lightly ironstained, alongdefects.

D SPT, N > 50 Wt = 2.4 t/m

3

Consistency / Density / Rock Strength VS – Very Soft Hd - Hard VL – Very Loose VL – Very Low


M - Medium


St – Stiff H – High VD – Very Dense

VSt – Very Stiff L – Loose Fb - Friable

sub-division design assignment 2011

Documents