盾构隧道施工临近建筑物风险等级评估方法

Study on the Methods for Risk Grade Assessment of Buildings Adjacent to Shield Tunnel Construction

基于层次分析理论,将量化分析和专家经验相结合,最大程度消除传统层次分析法中专家主观因素对评价结果的影响,提出了盾构施工对邻近建筑物影响的风险评估方法:①构造风险等级评价层次结构;②分层次建立两两因子的判断矩阵P;③各判断矩阵最大特征值计算及一致性检验;④由层次分析法确定指标体系中各因素的组合权重集A;⑤根据专家意见及工程经验建立评价因素集R;⑥计算风险值并进行建筑物风险等级评判。然后,通过一个具体工程案例的风险等级评估验证了该方法的有效性。该风险评估方法充分考虑了盾构隧道沿线建筑物的施工环境、水文地质条件、建筑物位置、建筑物建设年代、基础类型及埋深、建筑物等级等因素,在此基础上建立风险评价指标体系,对盾构隧道施工过程中临近建筑物的风险进行分析,将模糊的风险概念进行量化,进而根据建筑物风险评估的量化得分确定建筑风险等级,结果可为盾构周边建筑物的安全评估及其加固保护措施的选取提供依据。

Based on hierarchical analysis theory,quantitative analysis and expert experience are combined to eliminate the influence of expert subjective factors on evaluation results in traditional hierarchical analysis method.A risk assessment method for the impact of shield construction on adjacent buildings is proposed.Firstly,construct a hierarchical structure of risk grade evaluation.Secondly,build a two-factor judgment matrix P at different levels.Thirdly,calculate the maximum eigenvalue of each judgment matrix and check the consistency.Fourthly,determine the combined weight set A of each factor in the index system by the analytic hierarchy process.Fifthly,establish the evaluation factor set R based on expert opinions and engineering experience.Sixthly,calculate the risk value and evaluate the building risk level.Then,the effectiveness of the method is verified by the risk grade evaluation of a specific engineering case.The risk assessment method takes into full account the construction environment,hydrogeological conditions,building location,building construction age,foundation type,buried depth and building grade of the buildings along the shield tunnel.On this basis,a risk evaluation index system is established to analyze the risks of adjacent buildings during the construction of the shield tunnel.The fuzzy risk concept is quantified,and the building risk grade is determined according to the quantitative score of building risk assessment.The research results can provide a basis for the safety assessment of the surrounding buildings of shield and the selection of reinforcement protection measures.