树根桩承载能力的计算通常采用确定性安全系数法，计算过程中未能考虑材料、几何特性的随机性。鉴于此，为了更加科学合理地评估树根桩承载能力的安全性，利用可靠度反分析方法，对某隧道工程中影响安全系数的主要因素进行参数敏感性分析。研究结果表明：（1）考虑了参数随机性的可靠度模型安全系数计算结果小于确定性安全系数法的计算结果，树根桩的承载能力可靠度评估结果偏于安全；（2）桩的倾斜角度对树根桩承载能力的影响随斜桩倾斜度的增大而降低；（3）随机变量的变异性对树根桩的承载能力影响较大。因此，在实际工程中应尽可能对树根桩进行参数测试和分析，确定符合工程实际的概率分布参数。为了保障树根桩的施工质量，确保树根桩的安全性，应采取有效的控制措施降低树根桩施工过程中的风险和随机性。

The bearing capacity of root pile was usually calculated via the deterministic safety coefficient method without considering the randomness of materials′ characters and geometrical features. Given this, in order to evaluate the reliability of root pile′s bearing capacity more scientifically and reasonably, a reliability analysis method was used to analyze the parameter sensitivity of the main factors affecting the safety coefficient of the tunnel. The results show that: (1) the calculation result of reliability analysis method which considers parameter randomness is less than that of the deterministic safety coefficient method, thus the reliability assessment of root piles′ bearing capacity inclines to the safe side; (2) the influence of root pile′s inclination angle on its bearing capacity declines as the increase of its inclination angle; (3) the variability of random variables have a greater impact on root pile′s bearing capacity. Therefore, the parameters of root pile should be tested and analyzed as much as possible in practical engineering to confirm the probability distribution parameters according with the actual condition. For ensuring the construction quality of root pile and the reliability of its bearing capacity, effective control measures should be taken to reduce the risk and randomness in construction of root piles.