地面非对称填载对既有明挖隧道围岩压力的影响分析

Influence of Ground Asymmetric Filling Load on the Surrounding Rock Pressure of Existing Open Trench Tunnel

运用普氏理论、朗金土压力理论,对地面非对称填载作用下既有明挖隧道围岩的破坏模式和围岩压力计算进行了探讨。分析表明,地面非对称填载作用下既有明挖隧道的围岩压力计算按埋深可分为三种情况:深埋时采用普氏理论计算;浅埋且地面填载侧边墙与滑裂面之间会产生土拱效应时,该边墙所受的围岩压力采用普氏理论来计算,对侧边墙借助朗金土压力理论来计算;浅埋且地面填载侧边墙与滑裂面之间不产生土拱效应时,将左右边墙都当作挡土墙,借助朗金土压力理论来计算。

Based on the Protojiakonov′s theory and Rankine′s earth pressure theory,for the existing open trench tunnel under ground asymmetric filling load,the failure mode of the surrounding rock and the calculation of the surrounding rock pressure will be analysed in this paper.According to the embedment depth,the analysis shows that the surrounding rock pressure calculation can be divided into three situations：when the tunnel is deep buried,the Protojiakonov′s theory is used to calculate the surrounding rock pressure;when the tunnel is shallow buried and the side wall generates soil arching effect,the surrounding rock pressure calculation of the side wall will consider the soil arching effect and use the Protojiakonov′s theory.However,another side wall will use the Rankine′s earth pressure theory;when the tunnel is shallow buried and the side wall can′t generate soil arching effect,the two side walls may be regarded as retaining walls according to the Rankine′s earth pressure theory.