Development of design and construction methods to stabilize soft organic soils for the construction of rail, road and other infrastucture

Objective

The continuality increasing demand for building land for industry, housing and infrastructure (roads, railways, ports and air fields) is forcing the construction industry to build on land that was previously identified as unsuitable. Much of this unsuitable land comprises natural deposits which, because they contain organic matter, are highly compressible. Organic soils (ranging from slightly organic clays to peat) are found in many countries of Europe. The construction of foundations and embankments on highly compressible soils results in unacceptable total and differential settlements unless the compressible soil is removed, the construction founded beneath the compressible soil or long term precompression by surcharge is carried out before construction. The industrial objective of the project is to provide the European construction industry with competitive construction techniques, backed by guidance documents for their use, to stabilize soft organic soils. The new construction techniques would stabilize the soil by mixing the soil with binders like cement, lime and/or other industrial secondary materials (such as pulverized fuel ash) to create columns of stabilized soil or by mass mixing in situ.

Similar techniques are in use for non organic soil. The use of the techniques for organic soil (ranging from slightly organic clays to peat) needs further development of equipment and binding materials by laboratory and full scale field tests to assess the environmental and engineering behaviour of the stabilized soil. The research will provide a proven technology for stabilization of organic soft soils in a cost effective way. By full scale field and laboratory tests new mixtures of binders will be developed to stabilize these soils in situ. These tests must prove that the new production methods are environmental friendly and in accordance with the national and European regulations. Development and testing of equipment (including monitoring and automation systems) will lead to better mixing, penetration trough fills, more homogeneous stabilized soil and saving of binding materials.

Methods will be developed for mix design given the soil parameters, methods to design the configuration of the column and mass stabilization and to predict the effectiveness of the stabilization (stiffness and remaining settlement). New control and automation methods will be developed and tested. Only full scale tests in different European organic soil types, each with different applications (new infrastructure, widening of existing rail and road infrastructure, industrial areas and dykes) can prove the economic and technical opportunities of the new techniques. The results of the equipment development, the new mixtures of binders, the field and laboratory tests, the monitoring and automation systems will be combined to a design guide. This design guide will form a prenormative document for an European Standard for soil stabilization of (organic) clay and peat.

Programme(s)

• FP4-BRITE/EURAM 3 - Specific research and technological development programme in the field of industrial and materials technologies, 1994-1998

Topic(s)

• 0101 - Incorporation of new technologies into production systems

Funding Scheme

Coordinator

Participants (16)