Studies On The Engineering Characteristic Of Aeolian Sand & Reinforced Aeolian Sand Filling The Subgrade Of Heavy Haul Railway

In the Inner Mongolia,coal and mineral resources are abundant,but the existing roads and railways in the region can't meet the needs of transport for the coal and mineral resources,which seriously restricts the development of local economy.As a key project during the period of The 12 th Five-Year,Western Inner Mongolia to Central China railway is the new coal channel transport coal from the north to the south.This railway can transport the coal and mineral resources effectively,and has a great significance to promote the economic development of the region along the railway when it completion.MHTJ-2 of the Western Inner Mongolia to Central China railway across the Mu Us desert,high quality filler are scarce.soil,sand and gravel materials to fill the subgrade are required to transport from long-distance.In order to effectively control the investment of the project,it is necessary to make use of the abundant aeolian sand or reinforced aeolian sand along the railway to fill the subgrade.Whether the aeolian sand or reinforced aeolian fill the subgrade can meet the requirements of heavy haul railway needs further study.The research contents and results are as follows:(1)Come to conclusion from the test that the engineering properties of aeolian sand for MHTJ-2 of the Western Inner Mongolia to Central China railway,the section of aeolian sand gradation is not good,which belongs to the C group filler;Its main mineral is quartz and feldspar,the main chemical composition is Si O2?CaO?Al2O3 etc.;The dry density at natural condition between 1.54g/cm3~1.59g/cm3,relative density between 0.45~0.54;Low content of organic matter,weakly alkaline,soluble salt content is very low,it belongs to non saline soil,and has good permeability;Internal friction angle is between 33°~40°,the cohesion is very small,close to zero.(2)The Aeolian sand specimen compaction characteristics test shows that the aeolian sand can achieve higher dry density in dry state and optimum water content,the optimum water content is 14%,the maximum dry density is 1.79g/cm3;From compaction process test of subgrade filled by aeolian sand for the Western Inner Mongolia to Central China railway,the most ideal for the compaction effect which is the aeolian sand thickness in 35 cm ~ 45 cm,the moisture content in the vicinity of the optimal water content,first use the loader compacted for 6 times,and then the hydrostatic roller 2 times;the compaction effect in surface layer 10 cm of aeolian sand subgrade is poor,and with the time prolonging,the compaction quality will decline further.In order to ensure the compaction effect of the aeolian sand in surface,should be timely watering after the completion,and timely protection or make next layer of roadbed filling construction after the completion.(3)The design and construction of aeolian sand subgrade filling section mainly includes: principle and measures for foundation treatment in aeolian sand area,layered filling and geogrid laying for aeolian sand embankment,the hollow block revetment and arch skeleton protection etc.for aeolian sand embankment slope.(4)Through the finite element calculation software PLAXIS,the deformation characteristics and the stability of slope in the track and train load,which is filled by aeolian sand and different reinforced aeolian sand,and draws the following conclusion: The reinforced slope has little effect on the deformation behavior of embankment,the safety of embankment slope coefficient can be increased by 6%;Contrast without reinforcement,the maximum horizontal displacement of embankment with continuous reinforcement were reduced by 31%,the maximum vertical displacement decreases 15%,horizontal displacement of slope decreases 37%,the vertical displacement of the shoulder is reduced by 6%,safety factor of embankment slope increases 27%;The reinforced and slope protection is applied,the settlement and deformation of embankment decreases slightly,but the safety factor of embankment slope is improved 28.5%.The slope of aeolian sand embankment is easily failure affected by the environment,combined with the actual engineering,reinforced and reinforcement measures should be applied to protect the slope of aeolian sand embankment.