中膨胀土路堤包边方案及其试验验证

中膨胀土具有较强的吸水膨胀软化特性，其CBR值低于3％，不能满足路基对填料的强度要求，若用作路基填料必须进行处理。对中膨胀土路堤包边方案进行深入论证，对中膨胀土包边路堤边坡稳定性、路基强度与变形及石灰包边层的保湿作用进行分析。分析结果表明：中膨胀土包边路堤具有较好的浅层稳定性和整体稳定性；包边条件下，填土具有较高的强度和较低的变形，满足路用要求；包边层具有良好的防风化和保湿作用。在此基础上，提出中膨胀土路堤包边方案，并通过现场试验进行验证，试验验证表明，石灰包边方案能经受当地自然条件和气候条件的影响，能保证路基的稳定和安全营运。

WRAPPING METHOD FOR MIDDLE EXPANSIVE SOIL EMBANKMENT AND ITS EXPERIMENTAL VERIFICATION

Middle expansive soil should be treated before filled into roadbed because it will expand and soften remarkably after wetted and its CBR will be lower than 3%.The wrapping method for middle expansive soil embankment has been demonstratedi,n which the slope stability,strength and deformation of subgrade,and damp preservation action of lime stabilized wrapping soil for middle expansive soil wrapping embankment have been analyzed.The analyses indicate that the wrapping layer for middle expansive soil embankment improves its stability on slopes,and the slopes are characterized by shallow and deep stability under wrapping condition,the middle expansive soils within embankment possess higher intensity and lower deformation;wrapping layer on side of embankment possesses the good damp preservation and anti-weathering effect.The wrapping scheme for middle expansive soil embankment has been suggested and verified by site experiment.The testing verifies that the wrapping scheme for middle expansive soil embankment can withstand weathering and guarantee the stability of subgrade.