摘要
高速公路改扩建工程中,为保证道路服役性能和车辆行驶安全,拼宽新路与既有老路的沉降预测尤为重要。土体压缩模量是路基沉降计算的重要参数,其准确测量对沉降预测精准度有重要价值。本研究依托京沪高速扩建工程淮安—江都路段,通过现场孔压静力触探(Piezocone penetration testing,CPTU)测试地基土压缩模量,利用实测沉降基于分层总和法反演土层压缩模量,确定不同土层压缩模量与锥尖阻力的相关系数,并与相关性模型进行对比分析。研究表明,在对比的相关性模型中,SENNESET模型预测精度优于其他3种相关性模型;室内试验测量得到的土体压缩模量中,淤泥质黏土和黏土的实测结果较离散,误差较大,粉土和粉质黏土的精度较高,说明室内试验测量得到的压缩模量受外界因素干扰较大;CPTU测试得到的压缩模量受外界干扰较小,测试精度较高;路基4种土体的压缩模量与CPTU参数锥尖阻力q的相关系数分别为:淤泥质黏土层α=5.45,粉土层α=4.28,黏土层α=5.92,粉质黏土层α=6.58;对比现场监测数据证明,本文提出的基于CPTU测试估算高速公路路基沉降方法具有良好准确性。
In the highway reconstruction and expansion projects,in order to ensure the road service performance and vehicle driving safety,the settlement prediction of new road and the existing old road is particularly important.The compressive modulus of soil is an important parameter for subgrade settlement calculation,and its accurate measurement is of great value to the accuracy of settlement prediction.In this study,relying on the section from Huai’an to Jiangdu of the BeijingShanghai expressway expansion project,the compression modulus of the foundation soil was tested by on-site piezocone penetration testing(CPTU),and the compression modulus of the soil layer was also evaluated based on the measured settlement by the layered sum method.The results were compared and analyzed.The correlation coefficient was compared with the correlation model.The results shows that the prediction accuracy of the Senneset model is better than that of the other three correlation models.Among the soil compression models measured in the laboratory test,the measured results of silty clay and clay are more scattered and have larger errors.The accuracy of silty and silty clay is higher,indicating that the compressive modulus measured by the indoor test is greatly interfered by external factors.The compression modulus obtained by CPTU test is less affected by the external interference,and the test accuracy is high.For the four soil types of the foundation,the correlation coefficients between the compression modulus and the CPTU parameter cone tip resistance qt are:silty clay layerα,5.45;silt layerα,4.28;clay layerα,5.92;silty clay layerα,6.58.It is proved that the proposed method for estimating highway subgrade settlement based on CPTU test has satisfactory accuracy.
作者
王才进
史庆锋
刘松玉
何欢
蔡国军
常建新
王蒙
WANG Cai-jin;SHI Qing-feng;LIU Song-yu;HE Huan;CAI Guo-jun;CHANG Jian-xin;WANG Meng(Institute of Geotechnical Engineering,Souliieast University,Nanjing 211189,Jiangsu,China;School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,Anhui,China)
出处
《地基处理》
2022年第4期271-278,共8页
Journal of Ground Improvement
基金
国家自然科学基金(41877231,42072299,52008098)
江苏省自然科学基金(BK20200405)
江苏省交通运输科技项目(7921004042B)。
关键词
压缩模量
沉降计算
室内试验
锥尖阻力
相关性模型
compression modulus
settlement calculation
laboratory test
cone tip resistance
correlation model
