孔压静力触探(CPTU)探求高速公路软基固结系数研究

基于孔压静力触探(CPTU)的原理,简要介绍了利用CPTU试验求解地基土固结系数的理论方法,并以Tor-stensson理论模型为例,详细叙述了利用CPTU试验资料探求地基土固结系数的方法和步骤。结合连盐高速公路灌云三标的CPTU试验进行了实例计算,结果表明,现场所得的固结系数较室内试验的固结系数大1~2个数量级,与其他研究者的结果一致;在淤泥土层内,现场固结系数较室内试验所得的固结系数变化小,与现场资料反演值很接近;若采用此方法为实际工程提供设计固结系数时,进行修正后效果会更好。

Determination of Consolidation Coefficient for Expressway on Soft Ground from the Piezocone Penetration Test

Based on the piezocone(CPTU) penetration theory,several methods for deriving the coefficient of consolidation from CPTU pore pressure dissipation data were introduced in brief.The method and procedure to determine the coefficient of consolidation from(CPTU) dissipation tests were also presented in details by taking the example of Torstensson theory model.The CPTU tests results of soft ground in Lian-yan expressway were presented and the coefficient of consolidaion was obtained from the piezocne data.The results of the coefficient of consolidation were compared with labortory oedometer tests data and back-calculated values from field settlement data.(Comparisons) of the results indicated that the coefficient of consolidation determined by CPTU tests was higher than that measured in the labortory consolidation tests by 10 to 100 times,as reported by other researchers.The coefficient of consolidation values from CPTU tests were in less variation than those obtained by labortory tests and were in good agreement with the back-calculated coefficient of(consolidation) values in the soft marine clay.When the coefficient of(consolidation) from CPTU dissipation tests were used directly for(design,)it should be corrected by various factors in practice.