C25喷射混凝土抗压强度的概率统计规律

Probability Statistic Rule of C25 Shotcrete-Strength

在对某公路隧道喷射混凝土进行现场钻孔取芯和室内抗压强度试验的基础上，用χ^2检验法对收集的喷射混凝土抗压强度值分别选取正态分布、对数正态分布和极值Ⅰ型分布进行拟合检验，分析了喷射混凝土抗压强度的概率统计规律，并利用所得规律对其统计标准值进行了计算。计算结果表明，C25喷射混凝土抗压强度的概型分布符合正态分布，抗压强度的标准差为6．91～7．15MPa，变异系数为0．24～0．26，与C25模筑混凝土抗压强度的标准差5．43MPa、变异系数0．16相比，喷射混凝土抗压强度施工的均质性差，离散性大；C25喷射混凝土抗压强度统计标准值曲16～18MPa．与C25模筑混凝土抗压强度统计标准值17MPa比较接近。

In order to analyzing the distributation rule of shotcrete-strength, the expenimental data of shotcrete-strength were studied by Normal distribuation, logarithm Normal distributation and extremum I distributation, the distributations were examined by ~2 mothed, statistical standard values were calculated by the rule. Computation result shows that the C25 shotcrete- strength distribution submits Normal distribution, C25 shotcrete-strength＇s standard deviation is 6.91 ~ 7.15 MPa, its variation coefficient is 0. 24~0. 26, C25 moulded concrete strength＇s standard deviation is 5.43 MPa, its variation coefficient is 0. 16, the homogeneity of shotcrete- strength construction is worse, the divergence index of shotcrete-strength is larger, the standard value of shotcrete-strength is 16～18 MPa, it is near to the strength 17 MPa of moulded concrete. 4 tabs, 2 figs, 13 refs.