D11 Soil Stabilisation Checklist

D11 Soil Stabilisation Checklist
Index:

Problems:

Arisings from service trenches excavated to exposed existing underground services is often condemned to landfill
Special ingredients have been introduced to the market to allow service trench arisings to be relaid in the same service trench
At least one American product used by their military and globally in civil engineering, uses hazardous soluble chromium, in a trench that is likely to become a waterway for ground water, with very high potential to poison ground water which may potentially reach sources of drinking water

High ground water table or rainwater saturating subsoil and site vehicle movements will churn up a site and turn it into a vehicle trap and a no go area or result in mud puddles to splash new materials rendering them unacceptable for use

By adding lime, lime and cement or cement to saturated subsoil will use the excess water for hydration and turn the subsoil into a weak concrete like material, creating a firm dry base sufficient to provide a firm surface for vehicles or equivalent to a consolidated hardcore base for laying concrete floors or sub base for pavement, roads and runways
Excess subsoil can be used imaginatively in landscape modelling
Excess subsoil can be turned into topsoil by adding compost See D12

Dynamic compaction or consolidation allows improvement of sub-soil loadbearing capacity without the use of foundations
Dynamic compaction or consolidation and vibration techniques with or without the addition of stone or recycled concrete aggregate into piling hole can provide piled construction without the piles, i.e. no new concrete
Aggregate replacement See E10
Cement Substitution:
Lime in preference to lime-cement
- Using lime allows the process to be undone,
Lime-cement in preference to cement
- cement is more permanent
OPC replacement with GGBS (but expect a slower set)
Blended GGBS with OPC (to achieve normal setting times)

Soluble chromium in special ingredients aimed to permit service trench arisings being reuse in the same trench
Injecting cement in grout-form to stabilise ground
Excavation of subsoil
Disposal of subsoil, reuse on site where possible

Use Barrier creams before work in site to defend against lime, cement or concrete burns

Inert concrete demolition materials can be recycled on site:
- added to concrete mix
Inert concrete or masonry demolition materials can be recycled on site:
- used as consolidated hardcore or sub-base
- create a piling mat

Keeping existing materials onsite and improving them insitu is effective since it avoids the work transport and emissions removing them, avoids occupying landfill and avoids having to import materials to fill the gap created by their removal