考虑施工动态特征的大直径盾构隧道管片力学行为与精细化模型研究

The existing segments mechanical model of shield tunnel, had neither considered the influence of the time and space distribution of construction load, nor the otherness of joint bending stiffness in case the joint position or external load are different, resulting some difference between calculation results and practical situation. Taking a typical large-diameter shield tunnel as research object, the mechanical behavior of segments during construction will be studied. Based on three dimension of space and time, a synchronous grout diffusion - consolidation - dissipation model will be built, to analysis the influence of grouting pressure on the mechanical behavior of segment. And than the nonlinear equations and an iteration model about the segment joint will be built, to calculate the bending stiffness of it at different location and under different external load condition. Finally, considering the time and space distribution characteristics of construction load and the otherness of joint bending stiffness, and adopting the random sets theory to express the uncertainty of construction load and formation parameters, the mechanical behavior of the large diameter segment will be analyzed, and the segment deformation and damage characterization index will be put forward too. The calculated results will be compared with the all-ring segment load model test, providing the basis for accurate control of large diameter shield tunnel construction. This project will build an effective union computing platform among time-space distribution of construction load, nonlinear iteration of joint bending stiffness and random set finite element theory, to solve the underlying scientific problems about segment mechanical behavior and algorithm during construction, which will has significant theoretical value and application prospects.

既有盾构隧道管片结构受力模型，没有考虑施工荷载时空分布的影响，也没有考虑接头位置或外荷载不同时接头抗弯刚度的差异性，得到的计算结果与实际存在一定差距。本项目以典型大直径盾构隧道施工阶段管片力学行为为研究对象，基于三维空间与时间维度，构建同步注浆浆液扩散-固结-消散模型，分析浆液压力对管片力学行为的影响。之后建立关于管片接头抗弯刚度的非线性方程组，构建外荷载作用下管片不同位置接头抗弯刚度迭代模型并快速求解。最后，考虑施工荷载的时空分布和接头刚度差异性特征，基于随机集理论表达施工荷载和地层参数的不确定性，精细化分析大直径管片力学行为特征，提出管片变形损伤表征指标，并将计算结果与管片全环加载模型试验结果进行验证，为大直径盾构隧道施工精确控制提供依据。本项目将在荷载时空分布、非线性迭代和随机集有限元之间搭建有效联合计算平台，解决管片结构力学行为与算法的重要底层科学问题，具有显著理论价值与应用前景。

既有盾构隧道管片结构受力模型，没有考虑施工荷载时空分布的影响，也没有考虑接头位置或外荷载不同时接头抗弯刚度的差异性，得到的计算结果与实际存在一定差距。本项目以典型大直径盾构隧道施工阶段管片力学行为为研究对象，基于三维空间与时间维度，构建同步注浆浆液扩散-固结-消散模型，分析浆液压力对管片力学行为的影响。之后建立关于管片接头抗弯刚度的非线性方程组，构建外荷载作用下管片不同位置接头抗弯刚度迭代模型并快速求解。最后，考虑施工荷载的时空分布和接头刚度差异性特征，基于随机集理论表达施工荷载和地层参数的不确定性，精细化分析大直径管片力学行为特征，提出管片变形损伤表征指标，并将计算结果与管片全环加载模型试验结果进行验证，为大直径盾构隧道施工精确控制提供依据。本项目将在荷载时空分布、非线性迭代和随机集有限元之间搭建有效联合计算平台，解决管片结构力学行为与算法的重要底层科学问题，具有显著理论价值与应用前景。