基于普氏理论的双洞小净距隧道围岩压力计算模型研究

Research on Calculation Model of Surrounding Rock Pressure of Double-hole Small Clear Space Tunnel Based on Platts Theory

为揭示深埋双洞小净距隧道围岩压力的变化规律,本文考虑了双洞隧道中岩柱的影响及不同里程段围岩岩质差异性的影响,深入分析了普氏理论围岩压力和附加承载拱引起的附加围岩压力,构建了深埋双洞小净距隧道围岩压力的计算模型。研究结果表明,深埋双洞小净距隧道围岩出现偏压现象,偏压程度与岩质呈正比,表现为围岩岩质越差,偏压的效果越明显,拱顶的围岩压力值越大,周边围岩压力值则越小,通过围岩压力计算值与监测值比较发现,左边墙、左拱腰、拱顶、右拱腰、右边墙的偏差率分别在4.29%~10.53%、5.06%~9.76%、1.22%~9.57%、3.13%~8.82%、1.96~8.16%之间,表明了本文提出的围岩压力计算模型的合理性。研究结果可为隧道施工与监控量测提供参考。

In order to reveal the variation law of the surrounding rock pressure of deep-buried double-hole small clear distance tunnels,this paper considers the influence of the rock column in the double-hole tunnel and the influence of the difference of surrounding rock quality at different mileages,and deeply analyzes the surrounding rock pressure of Platts theory.And the additional surrounding rock pressure caused by the additional load-bearing arch,a calculation model of the surrounding rock pressure of the deep-buried double-hole small clear distance tunnel is constructed.The research results show that the phenomenon of eccentric pressure occurs in the surrounding rock of the deep-buried double-hole small clear distance tunnel,and the degree of eccentric pressure is proportional to the rock quality.The larger the value is,the smaller the surrounding rock pressure value is.By comparing the calculated value of the surrounding rock pressure with the monitoring value,it is found that the deviation rates of the left wall,left arch waist,vault,right arch waist and right wall are respectively 4.29%~10.53%,5.06%~9.76%,1.22%~9.57%,3.13%~8.82%,1.96~8.16%,which shows the rationality of the surrounding rock pressure calculation model proposed in this paper.The research results can provide reference for tunnel construction and monitoring measurement.