Linear Drainage Design Guide www.marshalls.co.uk/watermanagement

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www.marshalls.co.uk/watermanagement Sales Office: 0845 3020400 Email: [email protected] Contents Introduction Beany® Block Mini Beany® Traffic Drain Slot Drain (Duo and Mono) Landscape Drain

Email: [email protected] The Case for Linear Drainage 7 References and Further Reading 19

CLASS B125 125kN TEST LOAD CLASS C250 250kN TEST LOAD CLASS D400 400kN TEST LOAD CLASS E600 600kN TEST LOAD Footways, pedestrian areas, car parks, car parking decks and similar areas used by light, slowmoving traffic. Kerb-sides, general parking areas and hard shoulders that extend to a maximum of 0.5m into the trafficked area. Carriageways of roads (including pedestrian streets and parking areas) catering for all legal roadgoing vehicles. Private traffic areas used by vehicles imposing particularly heavy wheel loads. Special areas of abnormally heavy wheel loads e.g. aircraft pavements. Mini...

Traffic Drain Slot Drain Mono Landscape Drain Slot Drainage System Slot Drainage System Slot Drainage System Slot Drainage System Grid System Slot Drainage System Birco Lite Lite Cast Iron Grating 100 x 12mm slots Heelguard Top Unit Lite Channel 100 Cast Iron Grating 100 x 12mm slots In-Situ Lids 0/0 Birco 150 150 Cast Iron Grating 150 x 12mm slots 200 Cast Iron Grating 200 x 18mm slots Birco 300AS 300 Cast Iron Grating 125 x 20mm slots

The Case for Linear Drainage Introduction The growing demand for more cost-effective and less complicated drainage systems has led to modern linear drainage becoming the preferred choice amongst specifiers and contractors alike. Marshalls’ unique linear drainage systems combine the clear-cut advantages of linear drainage over traditional point drainage, with the benefits of a high quality, robust precast concrete product. Surface water interception More efficient at intercepting running water Ponding is reduced or eliminated as is streaming water across a site Fig. 1 Typical point drainage system,...

Selection Process Linear Drainage Product Selection Procedure The following pages describe the procedure for choosing the most appropriate Marshalls linear drainage system for a particular application. Marshalls’ comprehensive range of drainage systems can be split into three categories; 1. Combined Kerb and Drainage systems specifically designed for kerbside use; Beany Block Mini Beany 2. Slot Drainage Systems designed primarily (though not exclusively) for non-kerbside use; Max-E-Channel Slot Drain Duo and Mono Traffic Drain Landscape Drain Decathlon 3. Grid Drainage Systems designed primarily...

Selection Process Channel Drainage Systems Five channel linear drainage systems are available from Marshalls, designed primarily (though not exclusively) for non-kerbside applications; Max-E-Channel High Capacity Linear Drainage System Birco Linear Drainage System Landscape Drain Slot Drain Traffic Drain Decathlon Step 4 If the channel length is well in excess of 60m, refer to the Max-E-Channel range page 59 and Birco 300 page 101. Choose either a large capacity system with few outfalls or a medium capacity system with more outfalls (See note 2). Step 5 Determine the load classification of the...

Notes 1) Generally, where the linear drainage channel length is in the order of 60m, one centrally located outfall will be sufficient and a medium capacity system such as Birco Lite, Landscape Drain or Birco 100 can be used. Example A relatively small paved area of dimensions 50 x 50m can be easily drained by a 100mm wide channel system such as Birco Lite, Landscape Drain or Birco 100. One centrally located outfall to suit the existing main drainage system will be sufficient. This example shows typically two Birco Lite, 100 or Landscape Drain runs utilising in-built fall channels, with four outfalls...

Design Principles Introduction The basis of hydraulic design of any linear drainage system is fundamentally like any other engineering analysis; an assessment is made of the required performance level that the element has to achieve and this is compared to the element’s ability to accommodate this. In the case of linear drainage, how much water (peak run-off) will be flowing down the channel compared to the maximum stated flow capacity of the channel for the given conditions without causing any problems such as flooding. There are therefore two elements to any linear drainage design; a determination...

Other Considerations There are other aspects of linear drainage design beyond the factors given above. These include: Maintenance All surface water collection and transport systems will require maintenance to ensure efficient performance. Where linear drainage is designed for shallow gradients due care must be taken in the design for the effects of silting. Many systems are kept free from silting by the action of fast flow, but HR Wallingford’s research confirmed that velocities flows as low as 0.4m/s “caused silt to move”. Existing Drainage The location of existing drainage systems may often...

Design Principles Drainage Arrangements Due to the manufacturing flexibility available to Marshalls, we are able to offer several of our linear drainage and combined kerb and drainage systems with pre-sloped or inbuilt fall channels or base units. The inherent flexibility of inbuilt fall systems gives the designer a number of options to increase the flow capacity of the drainage run as circumstances dictate: Constant depth invert channels can be laid flat, or to a slope to increase the flow and discharge capacity (Figs. 8 & 9 opposite). Channels with progressively deeper inverts can be introduced...