现行隧道设计规范用偏心影响系数α表征偏压构件抗压强度随偏心距增加而降低的程度，引入可靠度设计时必须知道此系数的统计特征及计算公式的不确定性。通过３批试验筛选出９９组３０７根偏心受压构件的试验结果，整理出６种相对偏心距时α系数的均值、标准差及概率分布，回归整理成关系方程。所得结果在相对偏心较小时较现行规范提高８％～１１％，试验方法经过预研论证，结果可信 The current tunnel design code uses the eccentric influence coefficient α to characterize the degree of decrease of the compressive strength of the biasing member as the eccentricity increases. To introduce the reliability design, the statistical characteristics of the coefficient and the uncertainty of the calculation formula must be known. The test results of 99 sets of 307 eccentric compression members were screened through three batches of experiments. The mean, standard deviation and probability distribution of the alpha coefficients of the six kinds of relative eccentricities were sorted out and the regression equations were formulated. The result is 8% ~ 11% higher than the current standard when the relative eccentricity is small. The test method is preliminarily demonstrated and the result is credible