According to the existed original data , the test result and standards built in other countries , some mechanical capacities of steel and concrete are given in the thesis . so , interrelated diagrams and formulae about the discount coefficient calculation of strength are earned 根据已有的原始数据及试验结果，并参照国外的相关规范，文中总结了钢筋和混凝土材料的力学性能，得到强度折减系数计算的图表及相关公式。
( 2 ) when tunnel water is blocked up fully behind the lining , water pressure on the lining will reach maximum at last so long as surrounding rock near the lining is infiltrative no mattter how much the permeability coefficient of surrounding rock is ( 2 )隧道采用完全不排水措施时，只要衬砌附近的围岩渗水，衬砌背后与含水围岩有水力联系，不论渗透系数多大，衬砌背后最终水压会达到静水压，计算时水压不宜折减。
( 3 ) when the permeability coefficient of surrounding rock is over 10 - 4cm / s , water pressure on the lining will inevitably decrease until drainage quantity is large enough , having a large difference at every part of lining , which is minimum at the drainage part ( 3 )当围岩渗透系数大于10 ~ ( - 4 ) cm s时，需要排放较大水流量，衬砌背后水压才有明显折减，且隧道各个部位水压折减相差较大，排水点处部位水压折减最大。
