Bridges

Bridges Design

The ‘pull out’ resistance of LECA® Lightweight Expanded Clay Aggregate makes it an ideal solution for reinforced soil retaining walls and bridge design. Particularly when constructed over weak sub-soils or voids, this method has been proven to cut overall construction costs considerably. LECA® Lightweight Expanded Clay Aggregate is used extensively to reduce vertical loading.

THE ABILITY TO BLOW THE LECA® LIGHTWEIGHT EXPANDED CLAY AGGREGATE INTO HARD TO REACH AREAS AND IN CONDITIONS WHERE THE GROUND MAY BE DELICATE AND UNSAFE FOR HEAVY ACCESS USING HEAVIER, MORE TRADITIONAL MATERIAL, MAKES LECA® LIGHTWEIGHT EXPANDED CLAY AGGREGATE THE IDEAL SOLUTION WHICH HAS BEEN INVALUABLE TO CIVIL ENGINEERS ACROSS THE UK.

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Reducing Earth Pressure

Structures such as underground parking, tunnels or roof garden benefit greatly from the reduction in pressure and avoid additional costs of strengthening. Being light weight and round in nature, LECA® Lightweight Expanded Clay Aggregate can be transported and placed more easily than that of traditional fill in these difficult to access areas.

 

Bridges in the UK
leca lightweight fill
Highways in the UK
Bridges in the UK

Earth pressure of fill soil affects a supporting structure on a boundary surface between the supporting structure and earth. Supporting structures loaded by earth pressure include among others, retaining walls, sheet pile walls, back fill of bridges, basement walls, and foundations. 

Optimising Supporting Structures

As a fill material, LECA® Lightweight Expanded Clay Aggregate can effectively decrease the earth pressure. Due to its lightness the vertical earth pressure impacting the structure is up to 75% lower that induced by the natural rock fill. Lower earth pressure enables optimized dimensioning of supporting structures; and therefore application of LECA® Lightweight Expanded Clay Aggregate as backfill in these circumstances is usually a cost-efficient solution.

Minimise Earth Pressure

When LECA® Lightweight Expanded Clay Aggregate is applied to decrease the earth pressure, the following design aspects shall be taken into account:

  • Properties of underlying subgrade and its loading history
  • Pore water pressure in subgrade soil
  • Groundwater and/or perched water level and possible open water level
  • Allowed settlements and displacement of structure and its vicinity
  • Adjacent buildings and foundations
  • Dead and live loads
  • Construction reliability and feasibility of a structure
 

Newlands Bridge

Time Lapse Video on Installation

 
 

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