隧道衬砌水压力荷载及内力研究

通过轴对称解析计算和有限元数值计算隧道在不同衬砌渗透系数、不同注浆圈厚度、不同衬砌厚度条件下,衬砌背后的水压力、流量及衬砌内力,分析影响水压力的因素和水压力对衬砌内力的影响,轴对称解析计算和有限元数值计算结果显示水压力和流量十分接近。衬砌不透水时,水压力荷载系数不折减;在控制排水的条件下,调整衬砌渗透系数、注浆半径和衬砌厚度可以改变水压力、流量和衬砌内力。设计时正算水荷载,施工时通过监测流量反算水荷载,对水荷载设计进行检验和修正。

Research on Water Pressure Load and Internal Force of Tunnel Lining

In this paper, by using axisymmetric analytical calculation method and finite-element numerical calculation method,the water pressure behind the tunnel lining,the water flow rate,and the internal force of the tunnel lining were calculated under the condition of different lining permeability coefficients,different grouting circles,different lining thicknesses. Moreover,the factors affecting the water pressure were analyzed,and the influence of water pressure on the tunnel lining's internal force was also analyzed. From the research,it can be seen that the results of axisymmetric analytical calculation and finite element calculation are very close,either on water pressure or on water flow rate. This paper comes to the conclusion that when the tunnel lining is impervious,the water pressure load coefficient should not be reduced; and under the condition of controlled drainage,the water pressure load,water flow rate and internal force of tunnel lining can be changed by adjusting the lining permeability coefficient and the grouting radius as well as the tunnel lining thickness. It is suggested that the water pressure load calculation during design can serve as a normal calculation,and the water pressure load calculation by means of water flow rate monitoring during construction can serve as an inverse calculation so as to verify and modify the designed water pressure load.