摘要
膨胀土具有湿胀干缩的特性,在膨胀土区域修建道路时需要对膨胀土进行改良。结合某道路路基工程,采用轻型击实法,确定不同掺量水泥改良膨胀土的最佳含水率并制备试样。开展对改良膨胀土的自由膨胀率、无侧限抗压强度和收缩系数指标的研究,并对改良后膨胀土的拌合均匀性和碾压遍数进行试验,研究不同因素组合下的压实度,确定压实度最大的参数组合,并结合施工经济合理性分析。结果表明:膨胀土最佳水泥掺量为5%;在翻耕机5次翻拌和拌合机1次翻拌的机械组合下,膨胀土颗粒满足粒径要求;现场施工最佳参数组合为:初压、终压阶段分别静压2遍、1遍,复压强振6遍,压实厚度20 cm,碾压速度4 km/h。
The expansive soil has the swell-shrinkage performance,and the expansive soil needs to be improved when constructing roads in the expansive soil area.Combined with a road subgrade engineering,light compaction method was adopted to determine the optimum moisture content of cement modified expansive soil and prepare samples.The free expansion rate,unconfined compressive strength and shrinkage coefficient of the modified expansive soil were studied.The mixing homogeneity and rolling number of the modified expansive soil were tested to study the compaction degree under the combination of different factors,and the parameter combination with the largest compaction degree was determined.Combined with the economic rationality analysis of construction,the compaction degree of the modified expansive soil was determined.The results show that the best cement content of expansive soil is 5%;under the mechanical combination of stirring by a tiller for five times and stirring by a mixer for once,the expansive soil particles meet the requirement of particle size;the optimum parameters for site construction are as follows:twice of static pressure in the initial pressure stage and once of static pressure in final pressure stage,six times of complex pressure strong vibration,20 cm of compaction thickness,and 4 km/h of rolling speed.
作者
万红波
孙广
龚宋
王晨
WAN Hong-bo;SUN Guang;GONG Song;WANG Chen(China MCC5 Group Corp.,Ltd.,Chengdu 610063,China;School of Civil Engineering,Guilin University of Technology,Guilin 541004,China)
出处
《河南城建学院学报》
CAS
2023年第4期75-82,共8页
Journal of Henan University of Urban Construction
关键词
水泥
膨胀土
路基
施工参数
cement
expansive soil
subgrade
construction parameters
