软弱土层下预制拼装综合管廊受力性能分析

Analysis of Mechanical Behavior of Precast Concrete Utility Tunnel Under Soft Subsoil

基于ANSYS软件,建立了考虑土-结构共同工作的预制拼装混凝土综合管廊有限元分析模型,并在此基础上开展了预制拼装综合管廊在软弱土层下的受力性能参数分析,主要分析参数为软弱土层弹性模量。结果表明:软弱土层弹性模量减小会加剧管廊的不均匀沉降,沉降变形量与软弱土层弹性模量的关系函数可近似简化为对数函数;软弱土层对管廊结构的纵横向内力影响较大,当软弱土层的弹性模量降为周围非软弱土层弹性模量的17%时,可使侧壁底部截面横向弯矩减小31.9%或增大19.7%,使纵向弯矩达到该截面开裂弯矩的25%。

Finite element analysis model of precast concrete utility tunnel considering soil-structure interaction was set up by nonlinear finite element software ANSYS,and on this basis,analysis of mechanical behavior of precast concrete utility tunnel under soft subsoil was performed. The main analysis parameter is the elasticity modulus of soft subsoil. Analysis results show that soft subsoil will cause uneven settlement of the utility tunnel. The relationship between settlement and elastic modulus of soft soil layer can be approximately simplified to logarithmic function. The soft subsoil has great influence on the transverse and longitudinal internal forces of the utility tunnel. For example,the elasticity modulus of the soft subsoil decreases to 17% of the surrounding non-weak subsoil. The maximum reduction of additional bending moment of the lateral wall bottom section can reach 31. 9% and the maximum increment can reach 19. 7%; the maximum longitudinal bending moment can reach 25% of the cracking moment of the section.