在全面分析新奥法隧道施工风险影响因素基础上,首先确定主要影响因素,并根据其影响的模糊性与层次性特征建立新奥法隧道施工风险二级模糊综合评判模型;其次,通过深入研究各因素评价指标取值方法及隶属度函数选取原则,建立评价指标隶属度确定方法,并采用三角模糊数互补判断矩阵排序方法确定权向量,以体现评价指标重要程度取值的不确定性和专家判断的模糊性;然后,引进非线性模糊矩阵合成运算方法,反映评价指标极差值对评判结果的突出影响,进而建立新奥法隧道施工风险的非线性模糊评判方法,使新奥法隧道施工风险评价更具合理性与可操作性;最后,通过工程实例分析与计算,并与传统方法进行比较,表明了本文方法的可行性与合理性。
Based on a comprehensive analysis of the factors affecting the construction risk in NATM ( New Austria Tunnel Method) tunneling, the significant factors were identified. A two-stage fuzzy synthetic judgment model of construction risk in NATM tunneling was formulated according to the fuzzy and hierarchical features of the effects of these factors. The method to determine membership degree was presented by studying the method for evaluation indexes and the selection principle of membership degree function. The priority method of triangular fuzzy number complementary judgment matrix was used for calculating the weight vectors, which may reflect the uncertainties of the importance degree of evaluation indexes and the fuzziness of the judgment by experts. Nonlinear fuzzy matrix composition operating method was introduced to reflect the prominent effect to evaluation results when the evaluation index was worst. Nonlinear fuzzy judgment method of construction risk in NATM tunneling was developed, which could make the risk assessment much more rational and easier. The method was employed for analysis of projects and compared with the traditional method, which indicats that the method proposed here was feasible and reasonable.