盾构隧道管片接头的易损性分析和评价

Vulnerability Analysis and Assessment of Segmeng Joints in Shield Tunnel

摘要:

管片接头是盾构隧道结构力学性能的薄弱和关键部位.从抗弯、抗剪及抗渗三个方面，提出接头易损性评价方法.在轴力、弯矩和剪力作用下，考虑接头自身健康状况，并以混凝土、螺栓的应力状况和渗漏水作为评价指标，建立接头易损性评价模型.建立管片接头力学解析模型，分析接头的力学响应，并建立管片接头三维有限元精细化模型，对比验证解析模型的正确性.通过蒙特卡洛计算，获得大量计算样本，并在此基础上构建管片接头易损性的贝叶斯网络.根据接头易损性贝叶斯网络，分析接头易损性，并结合现场监测，反分析盾构隧道管片接头的健康状况，更新接头易损性预测，指导盾构隧道的正常运营维护.

Abstract:

Joints of shield tunnels are the weak but key elements of the whole structure. Considering the resistance capacity to bending moment, shear force and seepage, assessment of the vulnerability of shield tunnel segment joints was conducted and a model of vulnerability evaluation of segment joints subjected to inner forces was established under the consideration of the health state of joints. The stress of segment concrete and bolts, and seepage were taken as the assessment criteria of the model. Then, an analytical joint model was established to analyze the mechanical response of joints, and verified by the 3D refined numerical simulation. Based on a large number of learning cases offered by Monte Carlo simulation analysis, Bayesian networks were employed to evaluate the vulnerability of segment joints. Based on insitu monitoring data, the back analysis of health state of shield tunnel segment joints and the updated prediction of the vulnerability of segment joints are applied to help the operation and maintenance of shield tunnels.