考虑应力重分布的深埋圆形透水隧洞弹塑性解

ELASTIC-PLASTIC ANALYTICAL SOLUTION OF DEEP BURIED CIRCLE TUNNEL CONSIDERING STRESS REDISTRIBUTION

引进应力调整系数考虑岩体应力重分布的影响,针对渗流作用下深埋圆形隧洞求得了塑性半径和弹塑性应力解析解。通过该解答与考虑及不考虑渗流影响的弹性解进行实例对比表明:应力重分布的影响不能忽略。应力重分布使得环向应力增大,径向应力减小。渗透作用使得应力比不考虑渗透时减小,且在远离隧洞一定距离处径向应力超过环向应力。当内水水头较小时,塑性半径比不考虑渗流时略大,且塑性半径随着内水水头的增大而逐渐减小直到塑性区消失。

In order to reflect the effects of stress redistribution, the stress adjustment coefficient is introduced in this paper to develop the elastic-plastic analytical solution of deep buried circle tunnel. The developed solution is compared with the elastic solution with and without the consideration of the seepage filed, and it is found considering stress redistribution is necessary. The stress redistribution will increase the circumferential stress and decrease the radial stress. If the seepage field is considered, the stress will be underestimated, and the radial stress will exceed the circumferential stress at some positions far from the tunnel center. When the inner head is small, considering the seepage field will underestimate the plastic radius, which decreases with the enlarging of inner head until the plastic zone disappears eventually.