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

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.

Key words:water transportation tunnel; singlelayer lining under inner water pressure; segment joint; moment adjustment factor; full scale test