摘要
通过对几种双剪强度准则破坏面特征的分析,发现双剪剪应力型材料四参数统一强度理论和非线性统一强度理论具有描述高强混凝土多轴强度特性能力,在此基础上利用现有的多组高强混凝土的单轴抗拉强度、单轴抗压强度、双轴等压强度或常规三轴压缩强度试验结果确定以上两种强度准则中的材料参数,对二轴受力、常规三轴受力和真三轴受力状态的高强混凝土试验数据进行拟合分析,并与其他破坏准则进行了比较。结果表明:上述两种强度理论中剪应力型材料四参数统一强度理论与试验数据吻合较好,可描述常规三轴压强度随着围压增加的非线性特性,以及真三轴强度随中间主应力变化的整体趋势。该准则较其他常用混凝土准则描述效果也相对理想,参数b在[0,0.3]范围取值可获得较小的拟合偏差。此外,利用归一化方法对现有大量试验数据进行处理,以准则破坏面与所有试验点的偏差最小为优化判据,为该准则确定了一套普遍适用于高强混凝土的材料参数值。在缺少标定参数的试验成果时,可采用该普适参数初步确定高强混凝土的强度准则。
Comparative analysis of the failure surfaces of several twin shear strength criteria was conducted in this study. It was found that the strength properties of high-strength concrete （HSC） under multi-axial stress may be described by shear-type four-parameter unified strength theory （STFP-UST） and nonlinear unified strength theory （N-UST）. Then, the material parameters in the two strength criteria were deter- mined using uniaxial tensile, uniaxial compressive, biaxial compressive, or conventional triaxial strength. The two strength criteria were fitted and evaluated for the biaxial and triaxial test data of HSC, and the fit- ting effect was compared directly with other strength criteria. The STFP-UST exhibits a lower mean misfit for the test data of HSC than the N-UST. The STFP-UST can describe the nonlinear increase in conven- tional triaxial strength with confining pressure and the effect of the intermediate principal stress on strength. The fitting effect of the STFP-UST is relatively well compared with that of other common strength criteria for concrete. The mean misfit is low when the value of parameter b is in the range of [0, 0.3]. Based on a large amount of normalized test data of HSC, the general value of the material parameters （i.e. /3, A, B, C） are determined by minimizing the deviation of the failure surface from the test data. The STFP-UST for HSC can be roughly determined by the general parameters while test results are insufficient to obtain the exact parameters.
出处
《水利学报》
EI
CSCD
北大核心
2015年第1期74-82,共9页
Journal of Hydraulic Engineering
基金
国家自然科学基金资助项目(51279087
51339003)
国家重点基础研究发展计划(973)项目(2013CB035092)
关键词
高强混凝土
统一强度理论
强度准则
数据拟合
参数确定
high-strength concrete
unified strength theory （UST）
strength criterion
fitting data
determi- nation of parameter
