麻拉寨隧道水害综合整治措施及效果分析

基于麻拉寨隧道水害段轨道最大隆起值为28 mm,最大水平变形值为9 mm,运用FLAC3D软件模拟反算等效水头高度;数值模拟进一步验证了强降雨导致地下水壅高,高水压导致隧底中心水沟及边墙脚等薄弱部位产生劈裂破坏突水。通过降压泄水孔、封闭地表落水洞延缓地表水下渗、列车碾压等应急措施及隧底注浆加固、锚杆锚固、降压泄水洞等永久措施进行综合整治,并进行整治效果数值模拟。通过分级提速,2017年12月16日限速段恢复常速,恢复后轨道几何尺寸稳定。

Comprehensive Control Measures of Water Disease in Malazhai Tunnel and the Effect Analysis

For the section of Malazhai Tunnel subject to water disease, the rail therein has the maximum uplift of 28 mm and the maximum horizontal deformation of 9 mm and, with FLAC3D software, the equivalent height of water head was simulated and calculated reversely. This numerical simulation further proved that heavy rainfall would cause banked-up water level, thus due to the high water pressure, the water inrush as a result of splitting failure occurred at some weak positions, such as the central ditch at tunnel bottom and the foot of side wall. The comprehensive control measures, including the emergency actions, such as weep hole for depressurization, enclosed sinkhole to delay infiltration of surface water and train rolling, as well as the permanent actions, such as grouting reinforcement at tunnel bottom, bolt anchorage and drainage tunnel for depressurization, were conducted with the effect analyzed by numerical simulation. On December 16, 2017, through stepped acceleration, there recovered the normal speed in the section with speed limit. The physical dimensions of track was steady after the speed recovery.