盾构钢弹簧浮置板轨道结构高度不足的影响分析

Impact Analysis of Insufficient Height of Steel-spring Floating-slab Track Structure in Shield

受盾构结构空间狭小限制及施工误差影响,盾构中浮置板轨道结构高度不足问题在施工过程中普遍出现。为了研究此问题对浮置板受力和隔振效果的影响,本文针对目前此问题的常用处理措施,利用有限元软件建模分析这些措施对浮置板受力和隔振效果的影响。最终得出降低道床板厚度、减小隔振器纵向间距会增大浮置板1阶固有频率、降低浮置板的低频隔振效率,尤其道床板厚度的降低对浮置板隔振效果影响较大;隔振器纵横向间距减小会减小道床板内的拉、压应力,隔振器刚度增大会增大道床板内的应力。除此之外,目前的常用处理措施也会影响道床基底排水、浮置板施工及后期养护维修。

Influenced by the narrow space of shield and the error in shield construction, insufficient height of steel-spring floating-slab track structure in shield generally occurs during the construction. In order to study the influence on the floating slab stress and vibration isolation effect in this context, the finite element model is established to analyze the commonly used countermeasures. The results show that decreasing the height of slab and reducing the longitudinal spacing between isolators may increase the inherent frequency and reduce the vibration isolation efficiency in low frequency of floating slab especially the height of slab is lowered. Reducing the longitudinal and horizontal spacing between isolators will decrease the tensile stress and pressure stress of slab, while increasing isolator stiffness will increase the stress of slab. In addition, the current commonly used countermeasures may also affect the water drainage under the slab, the floating slab construction and the maintenance.