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EPS Geofoam 2001, 3rd International Conference, Salt Lake City,December 2001 9 <br /> STRESS DISTRIBUTION <br /> In order to observe the stress distribution in the EPS material below the bridge abutment at Lokkeberg bridge <br /> during construction and on a long term basis, 10 hydraulic earth pressure cells have been placed in different levels in <br /> the fill including 3 cells in the sand layer below the EPS fill.In fig. 15 the measured stress level after 10 years in <br /> — - Settlement tube <br /> Earth pressure cells <br /> Abutment <br /> 10cm concrete slab <br /> _.79 Figures in red <br /> 7m 1 indicates stress <br /> EPS 83 52 50 level in kPa <br /> 26 <br /> m <br /> * " <br /> E <br /> 28 <br /> 4 E <br /> F 30 a <br /> c� <br /> Figure 15.Lekkeberg bridge.Observed stress distribution and settlements in the cross <br /> section after 10 years in operation. <br /> service is indicated with red figures. <br /> Observations indicate that cell <br /> boundary effects may have <br /> 1989 1991 1993 1995 1997 1999 influenced the stress results, <br /> 120 especially in the first loading <br /> CL stage,probably due to poor <br /> m100 interaction between EPS and <br /> the steel casings for the earth <br /> m <br /> 80 pressure cells. <br /> C80 Long term measurements from <br /> .e 1 3 earth pressure cells below the <br /> cc <br /> fill and one situated 2 m higher <br /> 40 —Vertical load up have been plotted in fig. 16. <br /> Earth pressure 2 m above the bottom During the first year of <br /> 41 <br /> 20 —a Earth pressure below embankment,middle operation a stress decrease of <br /> In <br /> 0 0 —Earth pressure below embankment, left 15-30%was observed.Later <br /> —Earth pressure below embankment,right only small variations with time <br /> have been observed. Measured <br /> stresses corresponds well with <br /> the theoretical vertical load in <br /> Figure 16.Long term measurements of earth pressure at Lekkeberg bridge the lower part of the EPS fill. <br /> In the upper part of the fill(with a higher material strength)lower stress than expected has been measured in a zone <br /> under the central part of the embankment.One explanation could be some kind of arching effect due to large subsoil <br /> settlements in the middle of the embanlanent.This can clearly be seen in fig.IS where the measurements from the <br /> settlement tube are shown.In the lower part of the fill it is difficult to explain load concentration and deformation in <br /> Long term performance and durability of EPS as a lightweight filling material <br />