花岗岩残积土隧道渗流效应数值模拟研究

为探讨渗流效应对花岗岩残积土隧道的影响,通过将水注入围岩中实现渗流目的,并进行数值模拟。模拟过程中,设置了4组水压力,分别为0, 50, 100, 150 kPa,得到了不同压力与位移和支护结构之间的关系。研究结果表明:当围岩孔隙水压力为50 kPa时,不宜进行上台阶开挖;当围岩孔隙水压力为100kPa时,不宜进行下台阶开挖。隧道的开挖受水压力的影响较大,水压力越大,渗流范围越广,同时仰拱隆起现象越严重,此时顶部衬砌结构发生较大变形,故开挖隧道时应进行支护与监测。支护好上台阶后,应及时对围岩进行支护,以避免渗流过广而导致围岩出现较大位移。隧道下台阶的施工受多因素的影响,应及时对拱顶部位进行加固,避免出现工程事故。

A Numerical Simulation Study on Seepage Effect of Granite Residual Soil Tunnel

In order to study the influence of seepage effect on granite residual soil tunnel, seepage is realized by injecting water into surrounding rock, followed by a numerical simulation. In the simulation process, four groups of water pressures (0, 50, 100 and 150 kPa) have been set up, thus obtaining the relationship between different pressures, displacements and supporting structures. The results show that, with the pore water pressure of surrounding rock being 50 kPa, the excavation of the upper step is unfavorable; with the pore water pressure of surrounding rock being 100 kPa, the excavation of the lower step is more unfavorable. Tunnel excavation is greatly influenced by water pressure. The larger the water pressure is, the wider the seepage range is, and the more serious the inverted arch uplift will be. At this time, the top lining structure is characterized with a large deformation, which makes the supporting and monitoring of the tunnel excavation quite necessary. After supporting the upper steps, a timely supporting should be given to the surrounding rock so as to avoid a large displacement caused by excessive seepage. The construction of the lower steps of the tunnel is influenced by multiple factors, and the vault should be reinforced in time to avoid unnecessary engineering accidents.