公路工程湿陷性黄土地基评价方法

Evaluation method of highway subgrade at collapsed loess

基于《湿陷性黄土地区建筑规范》(GB50025-2004),借鉴黄土地区已建或在建公路项目的经验,结合公路工程的特点,从湿陷系数的测定、构造物类别的划分、建筑场地湿陷类型和湿陷等级的判定等方面对公路工程中湿陷性黄土地基的评价方法进行了探讨。认为目前执行的国家标准《湿陷性黄土地区建筑规范》来源于工业与民用建筑行业经验,不能完全适用于公路工程建设的需要。建议:对填土高度大于10 m的重要构造物,当基底压力大于300 kPa时,宜按实际压力测定黄土湿陷系数;挖方路堑应结合工程的实际情况判断黄土的湿陷性;湿陷性土层计算深度可根据沉降计算中压缩层深度的确定方法而定。

Based on the Chinese national technical standard＂Construction Criterion of Buildings at Collapsed Loess Area＂（GBS0025-2004）, combined with the features of highway engineering and the constructing experiences of highway at loess area, the evaluation method of highway subgrade at collapsed 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, the＂Construction Criterion of Buildings at Collapsed Loess Area＂can not meet the demand of highway engineering. It was suggested that： when the bottom 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 comoacted laver depth. 3 tabs, 1 fig, 10 refs.