考虑岩体及支护弹粘性的圆形巷道薄壁支护解析解

利用拉氏变换方法推导了圆形巷道处在平面应变情况下，在原岩的竖向和侧向应力相等时的薄壁筒支护弹粘性解析解，其中支护材料假设为马克斯韦尔体，岩体为包埃丁－汤姆逊体。以此为基础提出了考虑支护材料力学性质随时间变化的支护受力、变形计算方法，即把支护受力过程根据精度需要分成若干个首尾相接的时间区间，在每一区间内支护材料的力学参数取一定值，用不同区间内参数取值的不同，反映材料力学性质的变化，使用推得的解析计算

ANALYTIC SOLUTION FOR THIN WALL SUPPORT APPLIED IN A CIRCULAR TUNNEL BY TAKING INTO CONSIDERATION VISCOELASTICITY OF ROCKMASS AND SUPPORT

Analytic solution of viscoelasticity of thin wall support in a circular tunnel is deducted by using Laplace transformation for calculation of plane strain when the vertical and horizontal stresses in the virgin rock are equal, in which the structure material is regarded as Maxwell body and rockmass as Poyting-Thomson body. Based on this, a method for calculation of stress and strain of the support is proposed, in which the mechanical properties of the support material change with the time i. c., the stressing duration of support is divided into several continuous time zones. In each zone we can take a certain figure of mechanical parameter of support material, and we take many different values in different zones to represent variation of mechanical properties of support materials.The stress and strain of each zone is calculated by analytic formula. And the initial value of stress and strain in each zone is the final values of the previous zone. Based on the mechanical parameters of concrete in each time zone obtained in the laboratory and the data of parameters of rockmass measured at site,mechanical calculation of support used in one tunnel was made by using this method.