输水隧道管片环弯矩调整系数试验与分析

Experimental Study on Moment Adjustment Factor of Waterconveyance Tunnel Segment Lining

摘要:

由管片错缝拼装的隧道衬砌圆环中,接头部分的挠曲刚度小于与之邻接的管片的挠曲刚度,接头部分承受的弯矩不同于管片承受的弯矩.目前,考虑接头的影响主要通过弯矩调整系数ξ来实现.但是弯矩调整系数ξ还没有通用公式,一般需要通过足尺试验来确定.由于时间和成本问题,所有隧道工程都做足尺试验不现实,故工程中经常需要借鉴类似工程的经验,这必然带来很大的随意性.以上海市青草沙输水隧道工程为依托,进行输水隧道管片弯矩调整系数的足尺试验,改变作用在管片上的径向力P和轴向力F,得到了弯矩调整系数ξ和弯矩M、轴向力F、一环管片长度L的关系公式,对隧道衬砌设计有一定参考价值.

Abstract:

In segmental linings with staggered joints,the bending moment near a radial joint is weaker than that in its neighbor segment because of their difference in flexural rigidity.The joint effect is mainly materialized by adjusting the ratio of bending moment near a joint to that in the segment near the joint.Since there is no general formula to calculate the moment adjustment factor ξ so far,a full scale test will be one practical approach to determine the factor ξ.Because it is too expensive to do a full scale test for every project,referring to similar projects is a common practice for determining the factor ξ,which introduces much casualness to engineering projects.In this paper,a fullscale segment joint test was carried out,changing the radial force P and axial force F on lining segments,the internal force of the structure is calculated,the relationship between adjustment factor ξ and average moment M,axial force F,and segment length L is established,some useful conclusions are drawn.