Evaluation method of highway subgrade at collapsed loess

Based on the Chinese national technical standardi°Construction Criterion of Buildings at Collapsed Loess Areai±(GB50025-2004), combined with the features of highway engineering andhway at loess area, the evaluation method of highway subgraded loess was studied from the views of the measuring of collapsed coefficient, the dividing of structure form, and the determining of collapsed degree. It was pointed out that the highway engineering has its own features, thei°Construction Criterion of Buildings at CollapsLoess Areai±can not meet the demand of highway engineering. It was suggested that: when tbottom pressure of the structure which needs over 10 m filling earth is over 300 kPa, the collapsed coefficient should be measured according to the real pressure; when the excavation cutting is carried out at collapsed loess, the collapsibility should be determined according to the features of the real project conditions; the depth of collapsed loess should be calculated according to the method of determining the compacted layer depth.