Research on Lining and Surrounding Rock Load Sharing Ratio of Circular Pressure Tunnel

In combining with actual behaviors of united effects of surrounding rock-lined concrete-reinforcement after the occurrence of hydraulic engineering pressure tunnel lined cracks,and by means of non-linear finite element program,the united effects and material behaviors of surrounding rock an lining(concrete and steel bars) are simulated,and a fine,high-degree simulation 2-dimention(plain strain) numerical model is established.Through numerical analysis,the load sharing ratio between the lining and surrounding rock,the crack width and crack distribution laws,the concrete stress distribution laws,and the reinforced stress distribution laws are obtained under the conditions of satisfying the specification requirements and the economically rational reinforcement.The impact of the relative sliding occurred between lining and surrounding rock as well as surrounding rock parameter variations upon loading sharing ratio are analyzed.It has been found that when the relative sliding occurs between lining and surrounding rock,the reinforcing numbers should be increased,and that when the surrounding rock parameters change,there will be a great impact upon the adjacent crack spacing(crack numbers) and the lining load sharing ratio tends to rise slightly.