The longitudinal model test of shield tunnel

Longitudinal model test of shield tunnel was carried out in this paper. Four types of 50 rings of model tunnel were finished: complete continuous, continuous ring connected with longitudinal joints, nonstaggering and staggering installation. Then longitudinal loading test of 50 rings of the above four model tunnels embedded in sand were implemented. Uniform load and local load were respectively added on the overlay sand. The subsoil of model tunnel was firstly uniform sand and then soft soil would be added to modify the varied subsoil. The test study shows the longitudinal settlement curve is in accordance with Gauss Curve when the tunnel is under local load or the tunnel crosses through the uneven substratum; the settlement increment changes with the distance of load to the axis of tunnel as a linear relation; the influence of longitudinal local load is great when the load is 2-3D (D is the diameter of tunnel) to the axis of tunnel in cross section; larger longitudinal rigidity means larger influence range and fewer settlement. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. "Reprinted with permission from Elsevier".