盾构隧道非均质等效梁模型的建立与分析

Establishment of Heterogeneous Equivalent Beam Model of Shield Tunnel and Analysis

盾构隧道管片设计力学模型有均质圆环模型、多铰圆环模型、梁-弹簧模型等。在分析上述力学模型基础上,从管片接头截面力学性质出发,提出一种盾构隧道力学分析方法,建立非均质等效梁模型,即接头处单元与非接头处单元均采用等效参数不同的梁单元模拟,并从理论上推导接头处梁单元高度、宽度、弹性模量等截面性质等效参数解析式。根据现场试验数据,采用正交试验反演分析截面性质等效参数,验证理论解析式的有效性,得到一定条件下截面性质等效参数。将该模型内力结果与现场试验结果及梁-弹簧模型结果进行对比得出:非均质等效梁模型控制性截面内力值比现场试验值偏于安全,其安全系数介于现场试验值与梁-弹簧模型之间。结果表明:该模型可使管片接头力学性质更直观、明确,可在工程中推广应用。

At present mechanics models in designing shield el, multihinge ring model, beamspring model and so on. tunnel segments include the homogeneous ring mod In this paper on the basis of analysis on the above models, from the angle of the mechanical properties of segment joint sections, a new mechanical analysis meth od of shield tunnels was put forward. The inhomogeneous equivalent beam model was built in which both joint elements and nonjoint elements were simulated with beam elements of different equivalent parameters. The analytic equivalent parameters formulas of joint beam section properties, such as the height, width, elastic modulus and so on were deduced theoretically. According to field test data, the orthogonal test was applied to make back analysis on section properties equivalent parameters, verify the effectiveness of the above theoretical formulas, and get a group of section properties equivalent parameters under certain conditions. Comparing the results of internal forces of the new model with the results of the field tests and beamspring model, it is seen that the internal forces of the control sections of the new model are safer than the field test data and the safety factor of the new model lies between the field test data and beamspring model results. This model makes me chanical properties of segment joint clearer, and it can be popularly applied in engineering.