岩溶隧道衬砌水压力分布规律研究

Research of water distribution of tunnel lining in Karst region

长期以来隧道衬砌水压力问题,一直是人们争论的焦点。依托宜万铁路岩溶隧道工程,对不同防排水方式(即全封堵、堵排结合及排放方式)的隧道衬砌水压力分布规律进行研究,研究方法主要采用模型试验及现场测试方法,模型试验的比例尺为1∶16,试验台架可同时施加土压和水压。通过模型试验得出水压力分布规律:全封堵条件下衬砌背后水压力不能折减,注浆圈也不能有效减小水压力;隧道内排水后衬砌背后水压力明显减小,并随着排水量的增加,水压力基本成直线下降;相同排水量时,注浆效果越好,衬砌背后水压力减小越明显;隧道采用全排导方式时,衬砌仍承受一定的水压。由模型试验得出的水压分布规律的部分结论,在现场水压力测试中得到了验证。

Tunnel lining water pressure problem has been bone of contention for a long time. Relying on Yichang -Wanzhou Railway karst tunnels to research on distribution of linning water pressure on different anti - drainage patterns （the whole block, block combined with drainage and drainage mode ）. The primary research method was model test and field monitoring. Model test scale was 1： 16, and test apparatus could be applied earth pressure and water pressure. Acquiring the distribution of linning water pressure by model test： the lining water pressure can＇ t discounted and reduced by the grouting ring at the condition of whole block; the lining water pressure reduced significantly and linear decreased as the development of drainage discharge at the condition of block combined with drainage, simultaneously, the better the effect of grouting, the more outstanding the water pressure reduce; the lining still bear a certain degree of water pressure at the condition of drainage. A part of conclusion about distribution of linning water pressure from model test has been verified in field monitoring.