Over many years standard designs have emerged and mutated to deal with new Health and Safety requirements, design code changes and contractor capacities. These standards depend on loading and span and very importantly access to site for delivery of materials and plant. As the emphasis is on low cost the choice of materials and the interpretation of design codes is important.

I define my standard designs by most economic span lengths as:

Road

Stress laminated timber 3m – 6m,

Steel beam and timber deck 6m – 20m

Prestressed concrete 12m – 16m

Steel Beam and precast concrete deck planks 6m – 20m

Foot

Stress laminated flat 2m – 6m

Glentrool 4m – 12m

Struan Trusses 4m – 20m

Aerial mast 6m – 24m

Stress laminated arches 6m – 20m

Pictures of these designs can be seen in the gallery. Many hundreds of bridges have been built to these designs, and details have been adjusted over years to ensure the designs are improved. Because all of the gallery pictures are my designs and supervised by me any contractor problems have been documented and used to adjust future designs.

Costs

Bridges over the last few years of very low inflation have levelled out at around £1500/m2 of deck for mid spans. This includes abutments and bridges deck. As spans increase the decks become expensive and although there are still only 2 abutments longer spans can cost more. Similarly short spans can be expensive especially on road bridge because there are still 2 abutments.