降雨与自然状态下膨胀土基床的振动特性  

Vibration characteristics of subgrade in expansive soil area under simulated rainfall and natural conditions

作　　者：杨果林[1] 段君义[1] 杨啸[1] 徐亚斌[1] YANG Guo-lin DUAN Jun-yi YANG Xiao XU Ya-bin(School of Civil Engineering , Central South University , Changsha 410075, China})

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《浙江大学学报（工学版）》2016年第12期2319-2327,共9页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51278499;51478484);铁道部科技研究开发计划课题资助项目(2010G016-B);中南大学中央高校基本科研业务费专项资金资助项目(2016zzts401)

摘　　要：为研究铺设复合防排水板的膨胀土路堑基床的振动特性,结合云桂铁路建设工程,进行现场激振试验,对基床在自然状态、模拟降雨环境下各进行100万次激振,测试基床动应力、振动速度、振动加速度、路基沉降以及湿度的变化规律.结果表明:基床动应力、振动速度、振动加速度在激振初期随激振次数的波动性较大,且在基床表层范围内的横向分布不均匀性较明显;服役环境对动应力、沉降大小具有显著影响,但对动力响应沿基床深度的衰减规律影响不大;复合防排水板具有一定的防排水能力,且对基床内振动速度的分布具有一定的影响;路基顶面沉降量在自然状态下约为3mm,在模拟降雨下约为8mm;地基面沉降量可以忽略不计,路基沉降主要由基床沉降引起.In-situ dynamic tests were carried out on the cutting subgrade with excitation of 1million times,respectively,under service environments of natural state and simulated rainfall to study the vibration characteristics of cutting subgrade of expansive soil by using composite drainable waterproof plate along Yun-Gui high-speed railway.The dynamic stress of subgrade,velocity,acceleration,settlement and soil humidity were monitored.Results show that the values of dynamic characteristic parameters（dynamic stress,velocity and acceleration）have larger volatility at the beginning of the excitation and obvious inhomogeneity of the lateral distribution in the surface layer of subgrade.The influence of service environments on dynamic stress and settlement of cutting subgrade is significant,which is not so obvious on the attenuation law of the dynamic characteristic parameters with depth.Composite drainable waterproof plate has waterproofing and drainage capacity,and also some influence on the distribution of vibration velocity of subgrade.The settlement of subgrade surface is about 3mm under natural state and 8mm after simulated rainfall. The settlement of foundation is negligible,consequently,and the embankment settlement is mainly caused by subgrade.

关 键 词：膨胀土 路堑基床 原位激振试验 服役环境 振动特性 沉降变形 

分 类 号：TU443[建筑科学—岩土工程]