engleski

Foundation improvement for a building on loess soil

A high school two store building made of bricks, about 200 years old, suffered from settlement caused by increase of water content in loess soil, as a result of leakage of sewage system. Soil improvement with use of jet-grouting was designed and applied as a measure of foundation improvement and suppression of further settlement and fissuring of the building. Grouting was executed on outer and inner foundations, in the region affected by settlement, to the depth of 12 m under surface. In order to assure most suitable grouting technique a trial piles of jet-grouting were executed, aside from the object, using different pressures, direction of jet and time of jet action in place. With the pressure of 400 bar columns of 55 cm in diameter were obtained and it was accepted as a good result having in mind distance and spacing of boreholes under foundation. During execution of soil improvement measurement of soil deformation with depth and measurement of cracks in walls was performed, as well as topographic measurement of points on building. Before start of jet – grouting tunnels under building were filled with special concrete through the borehole from the surface. Comprehensive measurement of soil deformations, settlement and cracks on the building was performed before, during and after remediation work. Movements of the building ceased some time after the work was done, indicating that remediation work was successful.

settlement ; soil ; improvement ; jet-grouting ; monitoring

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