采用拟合的列车振动荷载,研究在上部列车振动荷载作用以及不同围岩等级、不同隧道间距条件下空间交叠盾构隧道的动力响应特性和损伤分布规律.结果表明:上部隧道衬砌振动加速度在拱底最大,拱腰相对较小,拱顶最小,下部隧道衬砌振动加速度在拱顶最大,拱腰相对较小,拱底最小;上部隧道的压致与拉致损伤均在拱底最大,拱腰次之,其余各处相对较小,且上部隧道底部约130°范围为损伤主要区域;随着围岩等级的提高,上部隧道衬砌的最大主应力逐步增大,最大主应力峰值由拱腰逐渐向拱底转移;随着隧道间距的增大,上部隧道衬砌的最大主应力逐步减小.%The dynamic response characteristics and the damage distribution law of space overlapping shield tunnel with different surrounding rock grades and different tunnel spacing under the conditions of the upper train vibration load were studied by adopting the simulated train vibration load. The results show that the vibration acceleration of the upper tunnel lining is maximum at the bottom of the arch,the acceleration is relatively small in the arch waist and the acceleration is the smallest at the vault. The vibration acceleration of the lower tunnel lining is maximum at the vault,which is relatively small in the arch waist and is the smallest at the bottom of the arch. The pressure damage and tension damage of the upper tunnel both reach the maximum at the bottom of the arch,followed by that of the arch waist and damages are relatively small in the rest places. The main area of damage is 130° range of the upper tunnel bottom.The maximum main stress of the upper tunnel lining gradually increases and the peak value shifts from the waist to the bottom of the arch with the increase of the surrounding rock grade.The maximum main stress of the upper tunnel lining gradually decreases with the increase of the tunnel spacing.
展开▼
