浅埋大跨隧道穿高压铁塔的注浆效果研究

Study on grouting effect of shallow-buried large-span tunnel through tower of high electric pressure

李家冲隧道为浅埋大跨隧道,其周围介质为Ⅴ级软弱围岩,隧道经过区域左洞侧上方有一高压电线塔。为保证高压电线塔的安全,防止由于隧道开挖引起的塔基不均匀沉降,需对围岩进行注浆预加固。通过应用FLAC3D,研究注浆前后隧道拱顶沉降和塔基沉降情况。数值分析表明:围岩在注浆后,拱顶沉降量和塔基沉降量有明显的减小,而且能有效控制塔基的不均匀沉降。与实际监测结果对比发现,围岩注浆效果较好,且模拟的计算值和实测值相近,说明应用FLAC3D进行注浆效果的事前分析是可行的。

Lijiachong tunnel is a shallow-buried large-span tunnel and its surrounding medium is V weak surrounding rock.There is a tower of high electric pressure through the left hole side of the tunnel area.In order to ensure the safety of the tower,and avoid the uneren settlement of tower foundation before the tunnel excavation,the surrounding rock should be carried out pre-grouting reinforcement.Tower foundation and vault settlement before and after grouting were numerically studied with FLAC3D,simulation results indicated that tower foundation and vault settlement were significantly reduced after grouting to surrounding rock,and it could effectively control the uneven settlement of tower foundation.Compared with the actual monitoring results,the surrounding rock grouting effect was better,and the measured values accord well with values of simulation.It is feasible to forecast the grouting reinforcement effect by FLAC3D simulation.