CAJ | 학술논문

为了给南京长江四桥基础工程设计与分析提供可靠的长江漫滩粘性土不排水抗剪强度Su参数,采用国外引进的孔压静力触探(CPTu)测试系统进行了现场原位试验,并以高质量土样的室内试验作为参考,对几种基于CPTu的Su确定方法进行了对比与评价,同时对所提出的圆锥系数Nk值进行了验证.试验结果表明:圆锥系数Nkt,Nke,N△u的大小取决于剪切试验模式及试验扰动程度；Nke一般比Nkt,N△u表现出更大的离散性；对于长江漫滩多夹层粘土地基,建议采用净锥尖阻力qt预测Su,相应的圆锥系数Nkt数值在7～16之间,平均值为11；应用CPTu新技术,可以为桥梁基础工程设计提供合理的设计参数.
위료급남경장강사교기출공정설계여분석제공가고적장강만탄점성토불배수항전강도Su삼수,채용국외인진적공압정력촉탐(CPTu)측시계통진행료현장원위시험,병이고질량토양적실내시험작위삼고,대궤충기우CPTu적Su학정방법진행료대비여평개,동시대소제출적원추계수Nk치진행료험증.시험결과표명:원추계수Nkt,Nke,N△u적대소취결우전절시험모식급시험우동정도；Nke일반비Nkt,N△u표현출경대적리산성；대우장강만탄다협층점토지기,건의채용정추첨조력qt예측Su,상응적원추계수Nkt수치재7～16지간,평균치위11；응용CPTu신기술,가이위교량기출공정설계제공합리적설계삼수.
In order to obtain the reasonable undrained shear strength Su for geotechnical analyses of bridge foundations in Yangtze River floodplain clayey soils, a site-specific study is conducted using the imported piezocone penetration test (CPTu)with dissipation phases at the Fourth Nanjing Yangtze River Bridge construction sites. Taking the values of Su from laboratory tests as references, several existing Su-predicted methods based on CPTu are compared and evaluated. To verify the presented cone factor Nk, additional test sites are selected and examined. The results show that the values of cone factors such as Nkt, Nke, and N△u, depend on the shear test mode and disturbance. Generally, the values of Nke show more scattering than those of Nkt and NΔu. For the stratified and layered sediments of the Yangtze River floodplain, it is recommended using the net cone resistance qT to estimate Su and the preliminary cone factor values Nkt are from 7 to 16, with an average of 11. It is also confirmed that the CPTu test, as a new technique in site characterization, can present reasonable parameters for bridge foundations.