水下盾构隧道纵向上浮理论解及工程应用

考虑静动态上浮力、浆液时变性和上覆土体反向压缩性因素,基于弹性地基梁的弯曲微分方程、有限元理论和变形、转角、剪力以及弯矩协调方程和边界条件,获得了水下盾构隧道纵向上浮的理论解,并运用于"河北第一盾"曹妃甸工业区综合管廊工程。工程算例表明,理论解与数值解最大误差在2.5%以内,与正常掘进段监测值吻合度较高,可用于分析水下盾构隧道纵向上浮。另外,所得理论解摒弃了数值计算模型建立和细化单元的繁琐过程,易被设计、施工人员接受和应用,同时也为完善相关设计规范提供一定参考。

Theoretical solution of longitudinal upward movement of underwater shield tunnel and its application

Considering the factors of static buoyancy and dynamic buoyancy, time variation of grout and compression of the overburden soil, based on curved differential equation of elastic foundation beam, finite element theory, boundary conditions and the coordination equations for deformation, angle rotation, shear and bending moment, a theoretical solution for longitudinal upward movement of underwater shield tunnel is obtained. It was applied to comprehensive pipe Project of Caofeidian Industrial Zone Gallery known as ‘the 1st shield of Hebei. The computation example of engineering shows that the maximum error of theoretical solution and numerical solution is within 2.5%. Furthermore, the result obtained by the proposed theoretical solution is well consistent with the monitoring result of normal excavation section and can be used to analyze the longitudinal upward movement of shield tunnel. Moreover, the theoretical solution has got rid of the tedious process when numerical model established and unit refined, so it will be accepted more easily by constructers or designers, so as to provide some reference to perfect the related design specifications.