STUDY ON FLAT SHELL-JOINT ELEMENT-FOUNDATION MODEL FOR SEGMENT OF SHIELD TUNNELS

Based on Mindlin plate theory and a layered and combined model of reinforced concrete, a flat shell-joint element-foundation model is proposed. The mechanical characteristics of segment joints can be simulated by the joint element model which is presented in this paper. The influence on the mechanical characteristics of lining segments, which is due to the reinforced bars and different structures of the joint zone, can be correctly simulated by the model. The mechanical and geometrical parameters of water-proof plastic, load cushion, conjunction bolts and concrete which can be obtained easily by test are used in the model instead of the joint stiffness parameters which are hard to be ascertained but used in the conventional model. Thusly, by using the model, the actual mechanical behavior of the segmental linings can be reflected and the calculation accuracy can be improved. The validity and effectivity of the model is demonstrated by examples.