基床系数室内试验成果修正及评价

Amendment and assessment on laboratory results of subgrade coefficient

基床系数室内试验方法分为固结法与三轴法,对目前规范中基床系数的室内测试方法进行了介绍,并对基床系数的室内试验成果进行尺寸效应等方面的修正,给出室内基床系数试验成果的修正公式。结合武汉轻轨交通二号线一期工程原位扁铲法基床系数试验成果和相应固结法基床系数试验成果,及武汉城市轨道交通四号线二期跨江段三轴法基床系数试验成果,并参考GB 50307-1999《地下铁路、轻轨交通岩土工程勘察规范》中的基床系数经验值,将基床系数固结法和三轴法进行比较分析,对规范中的两种基床系数室内试验方法进行了优劣方面的评价。

The methods to get subgrade coefficient in laboratory are divided into consolidation method and triaxial method.In this paper,the laboratory test methods of subgrade coefficient in the present specification are introduced,and laboratory test results of coefficient subgrade are amended with respect to the size effect,etc.Meanwhile,the modifier formula of laboratory test results of coefficient subgrade is presented.Combining with the test results of coefficient subgrade obtained by means of in-situ flat spade method and consolidation method in phase I project of the 2nd line of Wuhan Metro Project and those obtained by means of triaxial method in phase II project of the 4th line of Wuhan Metro,and referring to the empirical value of subgrade coefficient in ＂Mass Transit Railway and Light Rail Transit Geotechnical Engineering Investigation Norms＂（GB 50307—1999）,we carried out a comparison between the consolidation method and triaxial method.Furthermore,we presented an assessment on the two laboratory test methods which are recommended by the norms.