基于灰色关联度的高寒地区混凝土梁桥耐久性评估

On the durability evaluation of the concrete beam bridges in alpine region based on the grey relation degree

在考虑决策者偏好的情况下,为了合理地对高寒地区广泛分布的混凝土梁桥进行耐久性评估,提出了多维偏好线性规划法和灰色关联度相结合的评估模型。根据混凝土梁桥的特点和恶劣环境对混凝土梁桥的影响建立评价指标体系。基于主成分分析获取样本有序对集,并运用多维偏好线性规划法完成指标的初始赋权,再构造变权修正初始权重,引入灰色系统理论计算评价指标的灰色关联系数,建立了基于多维偏好线性规划法的灰色关联度评价模型。通过实例分析证明,该模型能更准确地判断混凝土梁桥的耐久性状态,表明了该评估模型的有效性和可操作性,可为高寒地区混凝土梁桥的维修加固提供理论依据。

This paper aims to conduct a reasonable durability assessment of the concrete beam bridges with the quality problems caused by the harsh environment in the alpine region for a long time.And,for the said purpose,we have proposed an evaluation model that can combine the preference linear programming method with the grey system theory on account of the preference of decision makers.To achieve the purpose,we have,first of all,managed to establish the durability evaluation index system through the analysis of the impact of the environmental factors on the beam bridge in the said region in combination with the features of the concrete beam bridge.And,then,we have conducted the principal component analysis in the case of multiple samples for evaluation of the index system,by choosing the principal component to solve the contribution rate and calculating the principal component score in addition to the sample score so as to obtain the ranks of the samples from the original decision matrix.And,furthermore,the initial weight of each index has to be determined based on the ordered set of the samples with the linear programming preferred method.And,finally,we have introduced the grey system theory for comprehensive evaluation and the exponential mathematical model to normalize the original index data to fit for the actual situation.And,then,the paper has managed to build up a variable weight formula to modify the initial weights of the index,so as to assess the durability grade of the concrete beam bridge and the grey correlation degree by integrating the initial weights of the index with the grey correlation coefficient.And,therefore,taking this model to the example analysis,the durability evaluation grade of each sample and each basic component of the concrete beam bridge can be worked out,which proves to be nearly consistent with the actualstatus-in-situ.And,what is more,on account of the preference of the decision makers,the modification of the initial weight can also make the index weight scientific.At the same time,it has also verified the effectiveness and maneuverability of the model so as to provide effective reference for the key points of maintenance and reinforcement of the bridge’s concrete girder in alpine areas and its choice and formulation of the maintenance schemes.