Abstract

Over the years, it has become obvious that simultaneous backfill grouting is of great significance to the design of the tunnel lining and process control of shield construction. It is essential to know the grout pressure distribution around the tunnel lining. The purpose of this study is to seek an alternative method to simulate the grout diffusion process and obtain pressure distribution of different time during simultaneous backfill grouting of tunnel construction. A lattice Boltzmann method (LBM) based free surface flow model is introduced and modified, and a Smagorinsky large-eddy simulation model serves to deal with the small-scale turbulent problem, which is a challenge for LBM to simulate the large-scale real-world engineering. The simulation results obtain the grout filling state with time and pressure distribution around the tunnel lining. Additionally, the grout pressures on site are measured at a ring in line 8 of Chengdu Rail tunnel, and the measurement results are also compared with ones taken from numerical simulation, it is showed that the numerical results are consistent with that of measurement on the whole. Through simulating different grouting strategies, it is concluded that for four-holes grouting schemes, the grouting pressures of upper holes are significant for the grout pressure distribution and should be paid most attention in construction.

摘要

多年来，同步回填注浆对隧道衬砌设计和盾构施工过程控制具有重要意义。了解隧道衬砌周围的灌浆压力分布至关重要。本研究的目的是寻求一种替代方法来模拟灌浆扩散过程，并获得隧道施工同时回填灌浆过程中不同时间的压力分布。引入并改进了基于格子玻尔兹曼方法（LBM）的自由表面流动模型，Smagorinsky大涡模拟模型用于处理小尺度湍流问题，这是LBM模拟大尺度实景的挑战。世界工程。模拟结果得到了隧道衬砌周围随时间和压力分布的灌浆状态。此外，在成都铁路隧道8号线一环现场实测灌浆压力，并将实测结果与数值模拟结果进行对比，表明数值结果与实测结果大体一致。 . 通过对不同注浆策略的模拟，得出对于四孔注浆方案，上孔注浆压力对注浆压力分布的影响很大，是施工中应重点关注的问题。