Using Trenchless Construction for Planned Communities
Planned communities employ thousands of hours worth of excavation time, all of which can be significantly reduced by using trenchless technology to build the underground infrastructure of the community instead.
As the population of major cities continues to grow and the need for residential development along with it, many town planners are opting for planned community developments. Townhome complexes with multiple units, cul-de-sac communities and subdivisions all fall under this trend to create new communities from scratch.
One significant advantage of planned communities is that developers can lay out the infrastructure required in the most efficient way for planning and implementation before the community is even built. Trenchless tech helps speed up the development program and save costs.
Many planned developments include green spaces and environmentally sensitive areas for the enjoyment of the community. Trenchless methods preserve the integrity of the environment during construction.
Infrastructure Elements Required for Planned Communities
The development of a new residential community requires many infrastructure elements. These are largely out of sight and out of mind for residents, but developers must provide these elements for the community to function.
Domestic waste must be piped from individual houses into a waste sewer network. A pipe network collects the waste and discharges it into the municipal system. Where possible waste sewers work on a gravity flow, but it may be necessary to include pump stations inside the community development.
New planned communities need a new potable water supply network. This network of piping receives water from a municipal supply connection and carries the water to individual houses. Potable water supply is a pressurized system requiring specific pipes and fittings.
Developers must take into account stormwater accumulation and runoff. All roads must slope towards a stormwater sewer system so that they remain free of standing water. The runoff from roofs, parking areas etc. also connects to the stormwater system. It is important for stormwater to be separate from the wastewater network to avoid overloading sewerage treatment plants with clean water.
Electricity and telecoms networks are also required for new planned communities. Supply comes from the community boundary and gets distributed to the individual housing units. Protective conduit shields electricity and telecoms cables from damage during construction activities.
Planning and Geotechnical Survey
As with any new development or trenchless project, planning and geotechnical reports are critical to the success of the project.
The engineering teams and architects of the development layout the individual plots, road networks and routes for underground infrastructure piping. Piping routes should be configured in the shortest routes to minimize material costs, but care should be taken to avoid areas that may be excavated later.
Using common routes also helps to lay multiple pipes in single trenchless bores to reduce the duplication of work and resources.
The importance of accurate geotechnical information cannot be overemphasized. The type of soil has a direct bearing on which trenchless technology is the most suitable. In addition, groundwater levels must be determined so that its influence on the construction project can be known and prepared for. Even though planned communities may be developed on “virgin” land, it is wise to test for the presence of underground piping in the area, as utilities, fuel, gas and other transfer pipes may have been laid there previously.
Best Trenchless Tech for Planned Communities
Microtunnelling is a trenchless method that gives a high accuracy of directional control. It is effective in a variety of soil types and below the groundwater table. Microtunnelling is also effective when the routing of the pipe passes through environmentally sensitive areas or where there is congestion of other facilities. The greatest advantage of this method for sewer network installation is the accurate directional control. Sewer networks rely on gravity for flow, therefore, a constant gradient is important to ensure that no blockages build up in the system. Even where pump stations are used, gravity flow is still important from one pump station to the next. This trenchless method is the most common method for sewer installations.
Horizontal Directional Drilling (HDD) is another popular method for waste sewer installations. It is relatively cheap. It has some limitations in terms of directional control but it has sufficient accuracy for slopes of 0.5% and above. HDD works at shallow depths with little surface disruption.
Mini HDD rigs are ideal for installing small bore piping like that of potable water supply. Up to 300-feet per day of piping can be installed using this method, which is far superior to what could be achieved with any open trench construction. These rigs are also ideal for the installation of conduit used for electrical and telecoms cables.
Opting for a Trenchless Build of Planned Communities
Planned communities provide a great opportunity to execute the infrastructure installation in the most efficient and cost-effective way. Trenchless methods are proven to reduce environmental impacts through avoiding the excavation of trenches. Perform geotechnical surveys, plan the infrastructure routes and implement a trenchless method of construction for the best results in your planned community.
Written by Phil Kendon | Technical Writer @ Trenchlesspedia
Phil Kendon has an undergraduate degree in engineering along with a masters in vocational practice. He has ten years of manufacturing experience in the oil and gas sector along with ten years of experience with non profits. Phil lives on the idyllic paradise island of Mauritius with his wife, Leigh, and 3 children, Timothy, Hannah and Luke. Here he pursues his work with non profits as well as his passion for writing.