info on exterior insulation/filling material, etc.-1999

Home Browse Search

EPS Geofoam 2001, 3rd International Conference, Salt Lake City,December 2001 10 the lowest EPS layer and likewise the low stress values in the upper part of the EPS fill.It may therefore be concluded that there still may be load distribution mechanisms in EPS fills that are not fully understood. Another test was performed to check the stress result.A dumper with a weight of 33 tons was placed at different distances from the abutment.In the case when it was placed directly upon the abutment an increase of 6 kPa was expected.The measured stress increases in the various fill levels with the Load=33 ton additional load from the dumper correspond well with the stress distribution without the dumper.The increase in stress levels from the dumper is shown in fig.17.The same tendency to reduced vertical pressure in a zone ______ beneath the abutment was also observed here.After unloading the abutment,the 3KN`�_ e.. ..a pressure cells immediately returned to 7 the initial stress levels. Earth pressure cells 4kN t7?UWffr 4m le EPS 2kN m 5 m ,Sm Attempts have been made to evaluate 6 the stress distribution in EPS blocks based on stress observations from the _-(SMM2 4m fightt�6kN/m 7kN/m ;4mTeft�• test hall experiments and stress observations at the Lokkeberg bridge. (gravel/sand) Stresses between blocks are of course Cell 1 2 difficult to measure and the results Yobtained vary quite a bit.In general Cell 5 15 measured stresses are,however,relatively low and indicate that the outer perimeter of the rn Stressdistribution 2:1 10 stress bulb may lie within a slope with a Fid ss 'on from addi ' jpa gradient 2:1 measured from the outer edge of 0 5 the loading area.However,depending on the w CII 284 0 stiffness of the loading area and possible load eccentricities,local stress concentrations may 0 500 1000 occur..In figure 18 the stress level at the bottom of the fill with distribution gradient 2:1 Time (days) is indicated with a black line and may be compared to the stress levels of cells 2,3,4 and Figure 18.Stress distribution measured in the test hall(fig.8) 5. REPAIR OF HJELMUNGEN BRIDGE Hjelmungen bridge is a three span,54 in long continuous concrete deck bridge completed in 1992 with abutments and pillars founded on concrete piles to firm ground.The 5 in high fills adjoining the bridge consisted partly of ordinary filling materials partly of waste material from the production of Leca building blocks.The fills rested on subsoil consisting of some 10—14 m of soft sensitive marine clay,partly quick and with a high water content. Some 2 years after completion it became evident that the bearing capacity of the soil beneath the abutments had been exceeded as excessive settlements occurred and the abutments inflicted damage to the bridge deck. Deformation monitoring was initiated and it soon became clear that immediate repair measures had to be initiated. Since settlement caused by the approach fills was the main problem,it was decided to reduce the load on the subsoil by some 30—40 kN/m2 in order to re-establish the initial subsoil stress conditions.This involved replacing parts of Long term performance and durability of EPS as a lightweight filling material