Experimental Study On Application Of High Consolidation To High Embankmentin Mengni Railway,Kenya

The use of dynamic compaction to reinforce the embankment and eliminate the settlement deformation is a common engineering treatment measure.Dynamic compaction can further strengthen the soil,reduce the compressibility of soil,eliminate uneven settlement and improve the physical and mechanical properties of foundation soil,which has been widely used in engineering practice.Based on the analysis of the existing dynamic compaction technology,this paper puts forward a new simplified model for strengthening the foundation by compaction and summarizes the strengthening effect and influence factor of the dynamic compaction in the field construction of the Meng-nei railway in Kenya.I have got the following conclusions:(1)The deformation law of embankment deformation along the depth direction of the embankment has been studied.I have concluded that the maximum cumulative settlement of the embankment occurs mainly in the lower part of the embankment.If the packing property is bad or the compacting is not compact,the yield area first appeares in the lower part of the embankment.Dynamic compaction should not be overlooked to improve the compaction of the lower part of the embankment.(2)I summarized the existing dynamic consolidation model systematically.Based the characteristics of soil-rock mixture embankment crater edge without uplift,I established the cylinder dynamic consolidation model of soil-stone mixture for high-filled embankment.The height of the cylinder is the effective reinforcement depth of the dynamic compaction.The diameter of the cylinder is the radial influence range.And then the concept of the average compaction degree of the dynamic compaction effect is put forward.(3)Based on the field Rayleigh wave test and finite element calculation,the method of determining the effective reinforcement depth and radial influence range of dynamic compaction is summarized,which provides the basis for the design of dynamic compaction parameters.It is suggested that the triangular or plum blossom arrangement should be used to reduce the difference of the strength of the foundation between the ram points and improve the uniformity of the embankment after the consolidation.(4)Dynamic compaction can improve the embankment compaction degree and reduce the post-construction settlement,which can effectively shorten the time of the ultimate control settlement.Combined with specific engineering examples,6000kN · m ramming can make the high embankment about 0.6m of settlement and the degree of compaction can be increased by about 7%after the eight times ramming.Dynamic compaction technology to deal with high embankment has huge economic and social benefits.