A parcel of land has been acquired for development as a residential sub-division. The area is adjacent to the grounds of a university and the developers have decided that this subdivision should be relatively 'up-market', with features that should make it a sought-after area for a professional clientele. The residential bocks are to be relatively generous in size (see further information below) and the subdivision will include several shops, envisaged to include a general store and a couple of speciality shops. These shops may attract business not only from this subdivision, but also adjacent existing residential areas and the university population. A notable feature will be a small artificial lake, which will be formed along a natural water-course which runs through the area. The undulating land and substantial percentage of the development that will be devoted to natural or planted bushland should combine to make this a quite picturesque residential area. The design of the subdivision should seek to maximize this as much as possible.
The subdivision has three gently curved roads through the land providing access to all of the residential blocks as well as the shopping centre. The remainder of the land in this development which is not devoted to residential blocks, the roads, the shopping centre and the lake, is to remain as natural grassed and treed land. Wherever there are house blocks, there is to be a 1.5m-wide reinforced concrete footpath located adjacent to the property boundaries. A total of 40 residential properties are to be provided in this development, their sizes to be in the range 1500 m2 - 2000 m2
It is possible that certain areas of existing native vegetation may be lost due to road or building construction. The developer has gained approval from Council for this to happen, but there will be strict controls placed on this. Any vegetation located within road reserves, the shopping centre boundaries or residential properties is to be considered as potentially lost, in the future if not during construction, and must be offset by re-planting of an area of vegetation at least equal to the affected area, on this same development.
A small lake/wetlands, with a surface area when full of approximately 7000 m2 is also to be provided, this will be one of the features of this development. This lake/wetlands will be formed by construction of a small earthen dam and no excavation will be undertaken. The dam will have a crest width of 2.0m, batters of 1 vertical: 2 horizontal, and will have a height of 0.4m above high water level (i.e. a minimum freeboard of 0.4m). A small spillway will provide for overflow and to ensure the dam isn't overtopped, but this need not be considered further. Where a road crosses the watercourse, a box culvert will be used to direct the water under the road.
A small shopping centre is to be located at approximately the middle of the subdivision. This location has been nominated as it puts the complex within easy walking distance of all parts of the subdivision. It also puts the complex at the most steeply-sloping area of land which, although the grades are still modest, the developer feels might be the least attractive to buyers of house blocks due to the increased building costs associated with building on sloping sites. As already mentioned, the shops are expected to serve not only this subdivision, but also the surrounding residential areas and the university community. Requirements of this shopping area are as follows:
The complex is to comprise one small building and a car parking area designed to accommodate 20 passenger vehicles.
The building is to be surrounded by a 2m wide reinforced concrete footpath on all sides. Beyond the footpath, there should be the following:
1. Along the rear of the building, there is to be an 8m-wide paved area for use by small trucks for deliveries to the shops. Leading to and from this area there needs to be a 4m-wide road at each end of the building.
2. Along the front of the building, there is to be a 2m-wide garden, then the parking area, which is to be designed in accordance with AS/NZS2890.1:2004.
To accommodate this small shopping centre and carpark, the area is to be reduced to a grade of 2% before any of the building or carpark works commence. Compacted and filled material may only be used to a maximum depth of 1.0m, so significant cut will be involved and a reinforced concrete retaining wall will be used to provide a vertical face to this cut. The retaining wall will run along the sides and rear of the building and the 8m-wide paved area and 4m-wide road located at the rear and ends of the building respectively will be measured to the vertical face of this wall. The top of the retaining wall should extend 1.0m above natural surface level and there will be a 1.0m high fence along the top of the wall. A retaining wall will also be required beside the 4m-wide road at each end of the building. This wall will be of reducing height to match the fall of the natural surface. Once the vertical step in levels reduces to 1.0m, the soil will be battered and planted with ground cover plants.
Task - Considerations for Sustainable Design
Your brief is to imagine that, as the engineering designer for this project, you have been asked by the clients (i.e. the owners of the project) to provide them with a report on issues of sustainability as they relate to engineering projects such as this.
Suppose the clients have said to you that they have no understanding of how issues relating to sustainability can be taken into account in engineering design and they are seeking a report that discusses this.
The issues may relate to aspects such as construction materials, environmental control within the building, provision of services such as water, etc, the use of swales in drainage design, and so on.