基于CPT大直径钢管桩可打入性分析方法研究  

Study on drivability analysis method of large-diametersteel pipe piles based on CPT

作　　者：胡寒阳 尹蒋松 沈振义 李飒[1,2] HU Hanyang;YIN Jiangsong;SHEN Zhenyi;LI Sa(School of Civil Engineering,Tianjin University,Tianjin 300350,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学建筑工程学院,天津300350 [2]天津大学水利工程仿真与安全国家重点实验室,天津300350

出　　处：《地震工程与工程振动》2024年第4期201-207,共7页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金重大项目(51890911)。

摘　　要：在海洋工程当中,大直径钢管桩常采用液压锤进行施工,桩基可打入性的准确预测对实际工程具有重要的意义。为探究静力触探试验(cone penetration test,CPT)锥尖阻力与单位锤击能量的关系,通过将CPT锥尖阻力转化为单位等效锥尖阻力,定义阻能比为单位等效锥尖阻力与单位锤击能量阻力之比,基于9个场地、72根钢管桩打桩记录以及CPT测试结果,探讨了不同土层(粉土层、砂土层以及黏土层)中阻能比随深度变化的关系,提出了基于CPT锥尖阻力的桩基可打入性预测方法。研究结果表明:单位等效锥尖阻力与单位锤击能量随深度变化具有相关性,阻能比在不同土层随深度变化具有各自的规律性。通过获得的不同土层阻能比随深度变化的关系式,利用CPT锥尖阻力可以直接获得打桩需要的单位锤击能量。经工程验证,使用本文提出的方法,预测打桩过程中单位锤击能量可行且具有一定精度。该方法仅需已知CPT锥尖阻力即可对单位锤击能量进行计算,可以快速地对桩基可打入性进行初步评估。In offshore engineering,large-diameter steel pipe piles are often installed with hydraulic hammers.Accurate analysis of pile drivability is of great significance in practice.In order to study the relationship between cone tip resistance of cone penetration test(CPT)and unit of hammering energy,the resistance to energy ratio was defined as the ratio of unit of equivalent cone tip resistance to unit of hammering energy resistance by converting cone tip resistance into unit equivalent cone tip resistance.Based on 9 sites,72 steel pipe piles driving records and CPT test results,the relationship of resistive energy ratio with depth in different soil layers(silt,sand and clay)was discussed,and a method based on CPT cone tip resistance was proposed.The results show that the variation of unit equivalent cone tip resistance with depth is consistent with that of unit of hammering energy with depth,but the change of resistance to energy ratio with depth in different soil layers are different.The relationship between the resistance energy ratio and depth in different soil layers was obtained,and it was possible to obtain the unit of hammering energy required for pile driving directly from the cone tip resistance of CPT.The method proposed in this paper is verified with an example in practice,and the results show that it is feasible.Because only the CPT cone tip resistance is needed to calculate the unit of hammering energy with the proposed method,it could be used to quickly evaluate the drivability of piles.

关 键 词：大直径钢管桩 静力触探试验 单位锤击能量 桩的可打入性 锥尖阻力 

分 类 号：TU473.1[建筑科学—结构工程]