Assignment Detail:- Part 1 - Civil Works Design
You are required to undertake a civil construction design project as outlined below- Your Assessor will take the role of the client for the purposes of this assessment task-
Design Specifications
The ProblemYou are a civil designer working for the state department of transportation- You have been assigned responsibility for the design of a truss bridge to carry a two-lane highway across the river valley shown below-
Design ObjectiveSatisfy all of the specifications listed below, while keeping the total cost of the project as low as possible-
Bridge ConfigurationThe bridge may cross the valley at any elevation from the high water level to 24 meters above the high water level-
If the elevation of the bridge is below 24 meters, excavation of the river banks will be required to achieve the correct highway elevation-
To provide clearance for overhead power lines -shown above-, the highest point on the bridge may not exceed an elevation 32-5 meters above the high water level -8-5 meters above the top of the river banks--
The bridge may consist of either standard -simple supports- or -arch supports-- If necessary, the bridge may also use one intermediate , located near the centre of the valley- If necessary, the bridge may also use cable , located 8 meters behind one or both abutments-
Each main truss can have no more than 100 and no more than 200 -
The bridge will have a flat, reinforced deck- Two types of concrete are available:
Medium-strength concrete requires a deck thickness of 23 centimetres -0-23 metres--
High-strength concrete requires a deck thickness of 15 centimetres -0-15 meter--
In either case, the deck will be supported by transverse spaced at 4 metre intervals- To accommodate these floor beams, your must have a row of joints spaced 4 meters apart at the level of the deck- These joints are created automatically when you begin a new design-
The bridge deck will be 10 meters wide, such that it can accommodate two lanes of traffic-
Member PropertiesMaterials- Each member of the truss will be made of either carbon steel, high-strength low-alloy steel, or quenched and tempered steel-- The members of the truss can be either solid bars or hollow tubes- Both types of cross-sections are square-Member Size- Both cross-sections are available in a variety of standard sizes-
LoadsThe bridge must be capable of safely carrying the following loads:Weight of the deck-Weight of a 5-cm thick , which might be applied at some time in the future-Weight of the steel floor beams and supplemental bracing members -assumed to be 12-0 applied at each deck-level joint--Weight of the main trusses-Either of two possible truck loadings:Weight of one standard H25 truck loading per lane, including appropriate allowance for the dynamic effects of the moving load- -Since the bridge carries two lanes of traffic, each main truss must safely carry one H25 vehicle, placed anywhere along the length of the deck--Weight of a single 480 kN Permit Loading, including appropriate allowance for the dynamic effects of the moving load- -Since the Permit Loading is assumed to be cantered laterally, each main truss must safely carry one-half of the total vehicle weight, placed anywhere along the length of the deck--
Structural SafetyThe bridge will comply with the structural provisions of the state specified standards, to include:Material densitiesLoad combinationsTensile strength of membersCompressive strength of members
CostThe cost of the design will be calculated using the following cost factors:Material Cost:Carbon steel bars - $4-50 per kilogramCarbon steel tubes - $6-30 per kilogramHigh-strength steel bars - $5-00 per kilogramHigh-strength steel tubes - $7-00 per kilogramQuenched and tempered steel bars - $5-55 per kilogramQuenched and tempered steel tubes - $7-75 per kilogramConnection Cost: $500-00 per jointProduct Cost: $1000-00 per productSite Cost:Reinforced concrete deck -medium strength- - $5,150 per 4-meter panelReinforced concrete deck -high strength- - $5,300 per 4-meter panelExcavation - $1-00 per cubic meter -See the Site Design Wizard for excavation volume-Supports -abutments and pier- - Cost varies -See the Site Design Wizard for specific values-$6,000 per anchorage
Required:1- Make a detailed list of all constraints and requirements to the bridge design-2- Prepare functional specifications3- Present at least 2 designs to meet the design specifications- The designs are to include, as relevant:calculations, which may include:loadssheer forcesbending momentsstressesconstruction materials and services quantitiesconstruction cost estimatesrecommended sizing of componentsrecommended materialsrecommended reinforcement sizing and locationdrawingsrisk assessment of:the existing conditionsthe application of the designmaintainability of the workshealth, safety and environmental requirementscontribution to ancillary documentation, which may include:design notesconstruction notessupplementary drawingsinput to the specifications
Note: The designs, and their development, should comply with relevant requirements including:legislative, organisational and site requirements and proceduresmanufacturer's guidelines and specificationsAustralian standardsCode of practiceEmployment and workplace relations legislationEqual Employment Opportunity and Disability Discrimination legislation
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